Showing papers in "Circulation-cardiovascular Imaging in 2012"

Assessment of Echocardiography and Biomarkers for the Extended Prediction of Cardiotoxicity in Patients Treated With Anthracyclines, Taxanes, and Trastuzumab

Abstract: Background— Because cancer patients survive longer, the impact of cardiotoxicity associated with the use of cancer treatments escalates. The present study investigates whether early alterations of myocardial strain and blood biomarkers predict incident cardiotoxicity in patients with breast cancer during treatment with anthracyclines, taxanes, and trastuzumab. Methods and Results— Eighty-one women with newly diagnosed human epidermal growth factor receptor 2–positive breast cancer, treated with anthracyclines followed by taxanes and trastuzumab were enrolled to be evaluated every 3 months during their cancer therapy (total of 15 months) using echocardiograms and blood samples. Left ventricular ejection fraction, peak systolic longitudinal, radial, and circumferential myocardial strain were calculated. Ultrasensitive troponin I, N-terminal pro–B-type natriuretic peptide, and the interleukin family member (ST2) were also measured. Left ventricular ejection fraction decreased (64 ± 5% to 59 ± 6%; P <0.0001) over 15 months. Twenty-six patients (32%, [22%–43%]) developed cardiotoxicity as defined by the Cardiac Review and Evaluation Committee Reviewing Trastuzumab; of these patients, 5 (6%, [2%–14%]) had symptoms of heart failure. Peak systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines treatment predicted the subsequent development of cardiotoxicity; no significant associations were observed for left ventricular ejection fraction, N-terminal pro–B-type natriuretic peptide, and ST2. Longitudinal strain was <19% in all patients who later developed heart failure. Conclusions— In patients with breast cancer treated with anthracyclines, taxanes, and trastuzumab, systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines therapy are useful in the prediction of subsequent cardiotoxicity and may help guide treatment to avoid cardiac side-effects.

Bicuspid aortic valve is associated with altered wall shear stress in the ascending aorta.

Abstract: Background— Hemodynamics may play a role contributing to the progression of bicuspid aortic valve (BAV) aortopathy. This study measured the impact of BAV on the distribution of regional aortic wall shear stress (WSS) compared with control cohorts. Methods and Results— Local WSS distribution was measured in the thoracic aorta of 60 subjects using 4-dimensional (4D) flow-sensitive magnetic resonance imaging. WSS analysis included 15 BAV patients: 12 with fusion of the right-left coronary cusp (6 stenotic) and 3 with fusion of the right and noncoronary cusp. The right-left BAV cohort was compared with healthy subjects (n=15), age-appropriate subjects (n=15), and age-/aorta size–controlled subjects (n=15). Compared with the age-appropriate and age-/aorta size–matched controls, WSS patterns in the right-left BAV ascending aorta were significantly elevated, independent of stenosis severity (peak WSS=0.9±0.3 N/m2 compared with 0.4±0.3 N/m2 in age-/aorta size–controlled subjects; P <0.001). Time-resolved (cine) 2D images of the bicuspid valves were coregistered with 4D flow data, directly linking cusp fusion pattern to a distinct ascending aortic flow jet pattern. The observation of right-anterior ascending aorta wall/jet impingement in right-left BAV patients corresponded to regions with statistically elevated WSS. Alternative jetting patterns were observed in the right and noncoronary cusp fusion patients. Conclusions— The results of this study demonstrate that bicuspid valves induced significantly altered ascending aorta hemodynamics compared with age- and size-matched controls with tricuspid valves. Specifically, the expression of increased and asymmetric WSS at the aorta wall was related to ascending aortic flow jet patterns, which were influenced by the BAV fusion pattern.

Myocardial Tissue Characterization Using Magnetic Resonance Noncontrast T1 Mapping in Hypertrophic and Dilated Cardiomyopathy

Abstract: Background— Noncontrast magnetic resonance T1 mapping reflects a composite of both intra- and extracellular signal. We hypothesized that noncontrast T1 mapping can characterize the myocardium beyond that achieved by the well-established late gadolinium enhancement (LGE) technique (which detects focal fibrosis) in both hypertrophic (HCM) and dilated (DCM) cardiomyopathy, by detecting both diffuse and focal fibrosis. Methods and Results— Subjects underwent Cardiovascular Magnetic Resonance imaging at 3T (28 HCM, 18 DCM, and 12 normals). Matching short-axis slices were acquired for cine, T1 mapping, and LGE imaging (0.1 mmol/kg). Circumferential strain was measured in the midventricular slice, and 31P magnetic resonance spectroscopy was acquired for the septum of the midventricular slice. Mean T1 relaxation time was increased in HCM and DCM (HCM 1209±28 ms, DCM 1225±42 ms, normal 1178±13 ms, P <0.05). There was a weak correlation between mean T1 and LGE ( r =0.32, P <0.001). T1 values were higher in segments with LGE than in those without (HCM with LGE 1228±41 ms versus no LGE 1192±79 ms, P <0.01; DCM with LGE 1254±73 ms versus no LGE 1217±52 ms, P <0.01). However, in both HCM and DCM, even in segments unaffected by LGE, T1 values were significantly higher than normal ( P <0.01). T1 values correlated with disease severity, being increased as wall thickness increased in HCM; conversely, in DCM, T1 values were highest in the thinnest myocardial segments. T1 values also correlated significantly with circumferential strain ( r =0.42, P <0.01). Interestingly, this correlation remained statistically significant even for the slices without LGE ( r =0.56, P =0.04). Finally, there was also a statistically significant negative correlation between T1 values and phosphocreatine/adenosine triphosphate ratios ( r =−0.59, P <0.0001). Conclusions— In HCM and DCM, noncontrast T1 mapping detects underlying disease processes beyond those assessed by LGE in relatively low-risk individuals.

Improved Detection of Myocardial Involvement in Acute Inflammatory Cardiomyopathies Using T2 Mapping

Abstract: Background— T2-weighted cardiac magnetic resonance imaging is useful in diagnosing acute inflammatory myocardial diseases, such as myocarditis and tako-tsubo cardiomyopathy (TTCM). We hypothesized that quantitative T2 mapping could better delineate myocardial involvement in these disorders versus T2-weighted imaging. Methods and Results— Thirty patients with suspected myocarditis or TTCM, referred for cardiac magnetic resonance imaging, who met established diagnostic criteria underwent myocardial T2 mapping. T2 values were averaged in involved and remote myocardial segments, both defined by a reviewer blinded to T2 data. In myocarditis, T2 was 65.2±3.2 ms in the involved myocardium versus 53.5±2.1 ms in the remote myocardium ( P 0.05 for all). T2 maps provided diagnostic data even in patients with difficulty breath holding. A T2 cutoff of 59 ms identified areas of myocardial involvement, with sensitivity and specificity of 94% and 97%, respectively. T2 mapping revealed regions of abnormal T2 beyond those identified by wall motion abnormalities or late gadolinium-enhancement positivity. Conventional T2-weighted short tau inversion recovery images were uninterpretable in 7 patients because of artifact and unremarkable in 2 patients who had elevated T2 values. T2-prepared steady-state–free precession images showed areas of signal hyperintensity in only 17 of 30 patients. Conclusions— Quantitative T2 mapping reliably identifies myocardial involvement in patients with myocarditis and TTCM. T2 mapping delineated a greater extent of myocardial disease in both conditions compared with that identified by wall motion abnormalities, T2-weighted short tau inversion recovery imaging, T2-prepared steady-state–free precession, or late gadolinium enhancement. Quantitative T2 mapping warrants consideration as a robust technique to identify myocardial injury in patients with acute myocarditis or TTCM.

Reference values for normal pulmonary artery dimensions by noncontrast cardiac computed tomography: the Framingham Heart Study.

Abstract: Background— Main pulmonary artery diameter (mPA) and ratio of mPA to ascending aorta diameter (ratio PA) derived from chest CT are commonly reported in clinical practice. We determined the age- and sex-specific distribution and normal reference values for mPA and ratio PA by CT in an asymptomatic community-based population. Methods and Results— In 3171 men and women (mean age, 51±10 years; 51% men) from the Framingham Heart Study, a noncontrast, ECG-gated, 8-slice cardiac multidetector CT was performed. We measured the mPA and transverse axial diameter of the ascending aorta at the level of the bifurcation of the right pulmonary artery and calculated the ratio PA. We defined the healthy referent cohort (n=706) as those without obesity, hypertension, current and past smokers, chronic obstructive pulmonary disease, history of pulmonary embolism, diabetics, cardiovascular disease, and heart valve surgery. The mean mPA diameter in the overall cohort was 25.1±2.8 mm and mean ratio PA was 0.77±0.09. The sex-specific 90th percentile cutoff value for mPA diameter was 28.9 mm in men and 26.9 mm in women and was associated with increase risk for self-reported dyspnea (adjusted odds ratio, 1.31; P =0.02). The 90th percentile cutoff value for ratio PA of the healthy referent group was 0.91, similar between sexes but decreased with increasing age (range, 0.82–0.94), though not associated with dyspnea. Conclusions— For simplicity, we established 29 mm in men and 27 mm in women as sex-specific normative reference values for mPA and 0.9 for ratio PA.

Morphological and functional adaptation of the maternal heart during pregnancy.

Abstract: Background— Pregnancy provides a unique model to study the adaptation of the heart in a physiological situation of transient load changes. The aim of this study was to assess the performance of the left ventricle (LV) in normal, uncomplicated pregnancies while considering the actual LV load and shape. Methods and Results— Serial echocardiographic examinations were performed in 51 women in each pregnancy trimester and 3 to 6 months after delivery. Data from 10 nulliparous, age-matched women were used as the control. Conventional parameters of LV function (ejection fraction) as well as myocardial deformation (strain) were interpreted, taking into consideration maternal hemodynamics and LV shape. Cardiac output increased during pregnancy because of a higher stroke volume in early pregnancy and a late increase in heart rate, whereas total vascular resistance decreased. Progressive development of eccentric hypertrophy was observed, which subsequently recovered postpartum. Sphericity index decreased from the first to the third trimester (1.92±0.17 versus 1.71±0.17) and returned postpartum to values comparable to the control. Although higher LV stroke work was noted toward the third trimester (5.9±1.1 versus 5.3±1.0 Newton meter, P <0.001), ejection fraction showed no significant changes. LV strain decreased significantly in late pregnancy (−19.5±2% to −17.6±1.6%, P <0.001) and returned to baseline values after delivery (−19.5±2%). Conclusions— Pregnancy is a physiological process associated with increased cardiac performance and progressive LV remodeling. These changes are not directly reflected by parameters traditionally considered to describe systolic function, such as ejection fraction and longitudinal deformation. While ejection fraction was insensitive to the functional changes, the transient decrease in longitudinal deformation becomes only plausible when considering the changes in LV geometry.

Clinical Context and Mechanism of Functional Tricuspid Regurgitation in Patients With and Without Pulmonary Hypertension

Abstract: Background— Functional tricuspid regurgitation (FTR) with structurally normal valve is of poorly defined mechanisms. Prevalence and clinical context of idiopathic FTR (Id-FTR) (without overt TR cause) are unknown. Methods and Results— To investigate prevalence, clinical context, and mechanisms specific to FTR types, Id-FTR versus pulmonary hypertension-related (PHTN-FTR, systolic pulmonary pressure ≥50 mm Hg), we analyzed 1161 patients with prospectively quantified TR. Id-FTR (prevalence 12%) was associated with aging and atrial fibrillation. For mechanistic purposes, we measured valvular and right ventricular (RV) remodeling in 141 Id-FTR matched to 140 PHTN-FTR and to 99 controls with trivial TR for age, sex, atrial fibrillation, and ejection fraction. PHTN-FTR and Id-FTR were also matched for TR effective-regurgitant-orifice (ERO). Id-FTR valvular alterations (versus controls) were largest annular area (3.53±0.6 versus 2.74±0.4 cm2, P <0.0001) and lowest valvular/annular coverage ratio (1.06±0.1 versus 1.45±0.2, P <0.0001) but normal valve tenting height. PHTN-FTR had mild annular enlargement but excessive valve tenting height (0.8±0.3 versus 0.35±0.1 cm, P <0.0001). Valvular changes were linked to specific RV changes, largest basal dilatation, and normal length (RV conical deformation) in Id-FTR versus longest RV with elliptical/spherical deformation in PHTN-FTR. With increasing FTR severity (ERO ≥40 mm2), changes specific to each FTR type were accentuated, and RV function (index of myocardial performance) was consistently reduced. Conclusions— Id-FTR is frequent, linked to aging and atrial fibrillation, can be severe, and is of unique mechanism. In Id-FTR, excess annular and RV-basal enlargement exhausts valvular/annular coverage reserve, and RV conical deformation does not cause notable valvular tenting. Conversely, PHTN-FTR is determined by valvular tethering with tenting linked to RV elongation and elliptical/spherical deformation. These specific FTR-mechanisms may be important in considering surgical correction in FTR.

Prognostic value of right ventricular longitudinal peak systolic strain in patients with pulmonary hypertension.

Abstract: Background— Right ventricular (RV) function is an important prognostic marker in patients with pulmonary hypertension. The present evaluation assessed the prognostic value of RV longitudinal peak systolic strain (LPSS) in patients with pulmonary hypertension. Methods and Results— A total of 150 patients with pulmonary hypertension of different etiologies (mean age, 59±15 years; 37.3% male) were evaluated. RV fractional area change and tricuspid annular plane systolic excursion index were evaluated with 2-dimensional echocardiography. RV LPSS was assessed with speckle-tracking echocardiography. The patient population was categorized according to a RV LPSS value of –19%. Among several clinical and echocardiographic parameters, the significant determinants of all-cause mortality were evaluated. There were no significant differences in age, sex, pulmonary hypertension cause and left ventricular ejection fraction between patients with RV LPSS <−19% and patients with RV LPSS ≥−19%. However, patients with RV LPSS ≥−19% had significantly worse New York Heart Association functional class (2.7±0.6 versus 2.3±0.8; P =0.003) and lower tricuspid annular plane systolic excursion (16±4 mm versus 18±3 mm; P <0.001) than their counterparts. During a median follow-up of 2.6 years, 37 patients died. RV LPSS was a significant determinant of all-cause mortality (HR, 3.40; 95% CI, 1.19–9.72; P =0.02). Conclusions— In patients with pulmonary hypertension, RV LPSS is significantly associated with all-cause mortality. RV LPSS may be a valuable parameter for risk stratification of these patients. Future studies are needed to confirm these results in the pulmonary hypertension subgroups.

Prediction of arrhythmic events in ischemic and dilated cardiomyopathy patients referred for implantable cardiac defibrillator: evaluation of multiple scar quantification measures for late gadolinium enhancement magnetic resonance imaging.

Abstract: Background— Scar signal quantification using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) identifies patients at higher risk of future events, both in ischemic cardiomyopathy (ICM) and nonischemic dilated cardiomyopathy (DCM). However, the ability of scar signal burden to predict events in such patient groups at the time of referral for implantable cardioverter-defibrillator (ICD) has not been well explored. This study evaluates the predictive use of multiple scar quantification measures in ICM and DCM patients being referred for ICD. Methods and Results— One hundred twenty-four consecutive patients referred for ICD therapy (59 with ICM and 65 with DCM) underwent a standardized LGE-CMR protocol with blinded, multithreshold scar signal quantification and, for those with ICM, peri-infarct signal quantification. Patients were followed prospectively for the primary combined outcome of appropriate ICD therapy, survived cardiac arrest, or sudden cardiac death. At a mean follow-up of 632 ± 262 days, 18 patients (15%) had suffered the primary outcome. Total scar was significantly higher among those suffering a primary outcome, a relationship maintained within each cardiomyopathy cohort ( P <0.01 for all comparisons). Total scar was the strongest independent predictor of the primary outcome and demonstrated a negative predictive value of 86%. In the ICM subcohort, peri-infarct signal showed only a nonsignificant trend toward elevation among those having a primary end point. Conclusions— Myocardial scar quantification by LGE-CMR predicts arrhythmic events in patients being evaluated for ICD eligibility irrespective of cardiomyopathy etiology.

Diagnostic accuracy of cardiac positron emission tomography versus single photon emission computed tomography for coronary artery disease: a bivariate meta-analysis.

Abstract: Background—Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits compared with single photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. We performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50% stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease. Methods and Results—We searched MEDLINE and EMBASE from inception through January 2012 and the references of identified studies for prospective, English language studies that evaluated the sensitivity and specificity of PET and/or SPECT MPI with coronary angiography as the reference standard and reported sufficient data to calculate patient-level true and false positives and negatives. Two investigators independently extracted patient and study characteristics; a third investigator resolved any disagreements. We identified 117 studies, including 108 evaluating SPECT MPI, 4 evaluating PET MPI, and 5 evaluating both modalities. Bivariate meta-analysis demonstrated a significantly higher pooled mean sensitivity with PET (92.6% [95% Confidence Interval, 88.3% to 95.5%]) compared with SPECT (88.3% [95% confidence interval, 86.4% to 90.0%]) (P=0.035). No significant difference in specificity was observed between PET (81.3% [95% confidence interval, 66.6% to 90.4%]) and SPECT (75.8% [95% confidence interval, 72.1% to 79.1%]) (P=0.39). Few studies investigated coronary angiography with PET. Only 5 studies directly compared SPECT and PET. Conclusions—In a meta-analysis of 11,862 patients, PET MPI demonstrated a higher sensitivity for coronary artery disease than SPECT MPI. No difference in specificity was detected in the pooled analysis of PET and SPECT MPI. (Circ Cardiovasc Imaging. 2012;5:700-707.)

Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Normal Ejection Fraction Is Associated with Severe Left Ventricular Dysfunction as Assessed by Speckle-Tracking Echocardiography: A Multicenter Study

Abstract: BACKGROUND: Low-flow low-gradient (LFLG) is sometimes observed in severe aortic stenosis (AS) despite normal ejection fraction, but its frequency and mechanisms are still debated. We aimed to describe the characteristics of patients with LFLG AS and assess the presence of longitudinal left ventricular dysfunction in these patients. METHODS AND RESULTS: In a multicenter prospective study, 340 consecutive patients with severe AS and normal ejection fraction were studied. Longitudinal left ventricular function was assessed by 2D-strain and global afterload by valvulo-arterial impedance. Patients were classified according to flow and gradient: low flow was defined as a stroke volume index ≤35 mL/m(2), low gradient as a mean gradient ≤40 mm Hg. Most patients (n=258, 75.9%) presented with high-gradient AS, and 82 patients (24.1%) with low-gradient AS. Among the latter, 52 (15.3%) presented with normal flow and low gradient and 30 (8.8%) with LFLG. As compared with normal flow and low gradient, patients with LFLG had more severe AS (aortic valve area=0.7±0.12 cm(2) versus 0.86±0.14 cm(2)), higher valvulo-arterial impedance (5.5±1.1 versus 4±0.8 mm Hg/mL/m(2)), and worse longitudinal left ventricular function (basal longitudinal strain=-11.6±3.4 versus -14.8±3%; P<0.001 for all). CONCLUSIONS: LFLG AS is observed in 9% of patients with severe AS and normal ejection fraction and is associated with high global afterload and reduced longitudinal systolic function. Patients with normal-flow low-gradient AS are more frequent and present with less severe AS, normal afterload, and less severe longitudinal dysfunction. Severe left ventricular longitudinal dysfunction is a new explanation to the concept of LFLG AS.

Nonculprit plaques in patients with acute coronary syndromes have more vulnerable features compared with those with non-acute coronary syndromes: a 3-vessel optical coherence tomography study.

Abstract: Background —Patients with acute coronary syndrome (ACS) have a higher incidence of recurrent ischemic events. The aim of this study was to compare the plaque characteristics of non-culprit lesions between ACS and non-ACS patients using optical coherence tomography (OCT) imaging. Methods and Results —Patients who had 3-vessel OCT imaging were selected from the Massachusetts General Hospital (MGH) OCT Registry. MGH registry is a multicenter registry of patients undergoing OCT. The prevalence and characteristics of non-culprit plaques were compared between ACS and non-ACS patients. A total of 248 non-culprit plaques were found in 104 patients: 45 plaques in 17 ACS patients and 203 plaques in 87 non-ACS patients. Compared to plaques of non-ACS patients, more frequent in ACS patients. Although the prevalence of plaques of ACS patients had a wider lipid arc (147.3±29.5° vs. 116.2±33.7°, p<0.001), a longer lipid length (10.7±5.9mm vs. 7.0±3.7mm, p=0.002), a larger lipid volume index [averaged lipid arc × lipid length] (1605.5±1013.1 vs. 853.4±570.8, p<0.001), and a thinner fibrous cap (70.2±20.2μm vs. 103.3±46.8μm, p<0.001). Moreover, thin-cap fibroatheroma (TCFA) (64.7% vs. 14.9%, p<0.001), macrophage (82.4% vs. 37.9%, p=0.001), and thrombus (29.4% vs. 1.1%, p<0.001) were microchannel did not differ between the groups, the closest distance from the lumen to microchannel in the patient was shorter in ACS subjects than in non-ACS (104.6±67.0μm vs. 198.3±133.0μm, p=0.027). Conclusions —Non-culprit lesions in patients with ACS have more vulnerable plaque characteristics compared to those with non-ACS. Neovascularization was more frequently located close to the lumen in patients with ACS.

Computed tomography myocardial perfusion imaging with 320-row detector computed tomography accurately detects myocardial ischemia in patients with obstructive coronary artery disease

Abstract: Background— Computed tomography coronary angiography (CTA) has been shown to be accurate in detecting anatomic coronary arterial obstruction, but is limited for the detection of myocardial ischemia. The primary aim of this study was to assess the accuracy of 320-row computed tomography perfusion imaging (CTP) to detect atherosclerosis causing myocardial ischemia. Methods and Results— Fifty symptomatic patients with recent single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) underwent a comprehensive cardiac computed tomography (CT) protocol that included 320-CTA, followed by adenosine stress CTP. CTP images were analyzed quantitatively for the presence of subendocardial perfusion deficits. All analyses were blinded to imaging and clinical results. CTA alone was a limited predictor of myocardial ischemia compared with SPECT, with a sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of 56%, 75%, 56%, and 75%, and the area under the receiver operator characteristic curve (AUC) was 0.65 (95% CI, 0.51–0.78, P =0.07). CTP was a better predictor of myocardial ischemia, with a sensitivity, specificity, PPV, and NPV of 72%, 91%, 81%, and 85%, with an AUC of 0.81 (95% CI, 0.68–0.91, P <0.001), and was an excellent predictor of myocardial ischemia on SPECT-MPI in the presence of stenosis (≥50% on CTA), with a sensitivity, specificity, PPV, and NPV of 100%, 81%, 50%, and 100%, with an AUC of 0.92 (95% CI, 0.80–0.97, P <0.001). The radiation dose for the comprehensive cardiac CT protocol and SPECT were 13.8±2.9 and 13.1±1.7; respectively ( P =0.15). Conclusions— Computed tomography perfusion imaging with rest and adenosine stress 320-row CT is accurate in detecting obstructive atherosclerosis causing myocardial ischemia.

Trabeculated (Noncompacted) and compact myocardium in adults: The multi-ethnic study of atherosclerosis

Abstract: Background— A high degree of noncompacted (trabeculated) myocardium in relationship to compact myocardium (trabeculated to compact myocardium [T/M] ratio >2.3) has been associated with a diagnosis of left ventricular noncompaction (LVNC). The purpose of this study was to determine the normal range of the T/M ratio in a large population-based study and to examine the relationship to demographic and clinical parameters. Methods and Results— The thickness of trabeculation and the compact myocardium were measured in 8 left ventricular regions on long axis cardiac MR steady-state free precession cine images in 1000 participants (551 women; 68.1±8.9 years) of the Multi-Ethnic Study of Atherosclerosis cohort. Of 323 participants without cardiac disease or hypertension and with all regions evaluable, 140 (43%) had a T/M ratio >2.3 in at least 1 region; in 20 of 323 (6%), T/M >2.3 was present in >2 regions. A multivariable linear regression model revealed no association of age, sex, ethnicity, height, and weight with maximum T/M ratio in participants without cardiac disease or hypertension ( P >0.05). In the entire cohort (n=1000), left ventricular ejection fraction (β=−0.02/%; P =0.015), left ventricular end-diastolic volume (β=0.01/mL; P 0.05). At the apical level, T/M ratios were significantly lower when obtained on short- compared with long-axis images ( P =0.017). Conclusions— A ratio of T/M of >2.3 is common in a large population-based cohort. These results suggest re-evaluation of the current cardiac MR criteria for left ventricular noncompaction may be necessary.

Interplay of coronary artery calcification and traditional risk factors for the prediction of all-cause mortality in asymptomatic individuals

Abstract: Background—Current guidelines recommend the use of coronary artery calcium (CAC) scoring for intermediate-risk patients; however, the potential role of CAC among individuals who have no risk factors (RFs) is less established. We sought to examine the relationship between the presence and burden of traditional RFs and CAC for the prediction of all-cause mortality. Methods and Results—The study cohort consisted of 44 052 consecutive asymptomatic individuals free of known coronary heart disease referred for computed tomography for the assessment of CAC. The following RFs were considered: (1) current cigarette smoking, (2) dyslipidemia, (3) diabetes mellitus, (4) hypertension, and (5) family history of coronary heart disease. Patients were followed for a mean of 5.6±2.6 years for the primary end point of all-cause mortality. Among individuals who had no RF, Cox proportional model adjusted for age and sex identified that increasing CAC scores were associated with 3.00- to 13.38-fold higher mortality risk. The ...

Distribution of inflammation within carotid atherosclerotic plaques with high-risk morphological features: a comparison between positron emission tomography activity, plaque morphology, and histopathology.

Abstract: Background —Several high-risk morphological features (HRM) of plaques, especially in combination, are associated with an increased risk of a clinical event. While plaque inflammation is also associated with atherothrombosis, the relationship between inflammation and number of HRM is not well understood. Methods and Results —Thirty-four patients underwent 18 flurodeoxyglucose positron emission tomography (FDG-PET) imaging and carotid atherosclerotic inflammation was assessed (target-to-background ratio, TBR). Additionally, in a subset of 10 subjects with carotid stenosis who underwent carotid endarterectomy (CEA), inflammation was histologically assessed (CD68 staining). Vessel wall morphology was examined using computed tomography for the presence of visible plaque and presence of three HRM: positive remodeling (PR), luminal irregularity (LI), and low attenuation (LAP). A total of 100 vascular segments were analyzed, of which 69 contained visible plaque (26 plaques with ≥ 1 HRM). Inflammation, by FDG uptake (TBR), was higher in plaques with (vs. without) HRM (Mean ± SEM: 2.21 ± 0.20 vs. 1.66 ± 0.07, p=0.03), and increased with the number of HRM observed (p<0.001 for trend). Similarly, inflammation within atherosclerotic specimens (% CD68 staining) was higher in plaques with (vs. without) HRM (Median [IQR]: 10[0,19.85] vs. 0[0,1.55], p=0.01) and increased with the number of HRM observed (p<0.001 for trend). Conclusions —Inflammation, as assessed by both FDG uptake and histology, is increased in plaques containing high-risk morphological features and increases with increasing number of HRM. These data support the concept that inflammation accumulates relative to the burden of morphological abnormalities.

Association of Myocardial Deformation With Outcome in Asymptomatic Aortic Stenosis With Normal Ejection Fraction

Abstract: Background—Current guidelines recommend intervention for symptomatic aortic stenosis, but the management of asymptomatic aortic stenosis remains controversial. As left ventricular global longitudinal strain (GLS) has been shown to predict cardiovascular outcome, we sought to find whether its use could guide the assessment of risk in these patients. Methods and Results—We prospectively followed 79 patients with severe asymptomatic aortic stenosis (39 men; mean age, 77 ± 12 years; aortic valve [AV] area index, 0.36 cm2/m2). In addition to standard echocardiography, speckle strain was measured to assess GLS. Patients were followed for cardiac death and AV replacement driven by symptom development. A multivariable Cox regression was performed to identify associations with events. During 23 ± 20 months, 3 patients had cardiac death and 49 underwent AV replacement. Event-free survival was 72 ± 5% at 1 year, 50 ± 5% at 2 years, and 24 ± 5% at 4 years. Death and AV replacement were predicted by GLS (hazard ratio ...

Global longitudinal strain predicts long-term survival in patients with chronic ischemic cardiomyopathy.

Abstract: BACKGROUND Left ventricular (LV) global longitudinal strain (GLS) is a measure of the active shortening of the LV in the longitudinal direction, which can be assessed with speckle-tracking echocardiography. The aims of this evaluation were to validate the prognostic value of GLS as a new index of LV systolic function in a large cohort of patients with chronic ischemic cardiomyopathy and to determine the incremental value of GLS to predict long-term outcome over other strong and well-established prognostic factors. METHODS AND RESULTS A total of 1060 patients underwent baseline clinical evaluation and transthoracic echocardiography. Median age was 66.9 years (interquartile range, 58.4, 74.2 years); 739 (70%) were men. The median follow-up duration for the entire patient population was 31 months. During the follow-up, 270 patients died and 309 patients reached the combined end point (all-cause mortality and heart failure hospitalization). Compared with survivors, patients who died (270, [25%]) had larger LV volumes (P -11.5% (log-rank χ(2), 13.86 and 14.16 for all-cause mortality and combined end point, respectively, P<0.001 for both). On multivariate analysis, GLS was independently related to all-cause mortality (hazard ratio per 5% increase, 1.69; 95% confidence interval, 1.33-2.15; P<0.001) and combined end point (1.64; 95% confidence interval, 1.32-2.04; P<0.001). CONCLUSIONS The assessment of LV GLS with speckle-tracking echocardiography is significantly related to long-term outcome in patients with chronic ischemic cardiomyopathy.

Ultrasmall superparamagnetic particles of iron oxide in patients with acute myocardial infarction: early clinical experience.

Abstract: Background— Inflammation following acute myocardial infarction (MI) has detrimental effects on reperfusion, myocardial remodelling, and ventricular function. Magnetic resonance imaging using ultrasmall superparamagnetic particles of iron oxide can detect cellular inflammation in tissues, and we therefore explored their role in acute MI in humans. Methods and Results— Sixteen patients with acute ST-segment elevation MI were recruited to undergo 3 sequential magnetic resonance scans within 5 days of admission at baseline, 24 and 48 hours following no infusion (controls; n=6) or intravenous infusion of ultrasmall superparamagnetic particles of iron oxide (n=10; 4 mg/kg). T2*-weighted multigradient-echo sequences were acquired and R2* values were calculated for specific regions of interest. In the control group, R2* values remained constant in all tissues across all scans with excellent repeatability (bias of −0.208 s−1, coefficient of repeatability of 26.96 s−1; intraclass coefficient 0.989). Consistent with uptake by the reticuloendothelial system, R2* value increased in the liver (84±49.5 to 319±70.0 s−1; P 0.05) 24 hours after administration of ultrasmall superparamagnetic particles of iron oxide. In the myocardial infarct, R2* value increased from 41.0±12.0 s−1 (baseline) to 155±45.0 s−1 ( P <0.001) and 124±35.0 s−1 ( P <0.05) at 24 and 48 hours, respectively. A similar but lower magnitude response was seen in the remote myocardium, where it increased from 39±3.2 s−1 (baseline) to 80±14.9 s−1 ( P <0.001) and 67.0±15.7 s−1 ( P <0.05) at 24 and 48 hours, respectively. Conclusions— Following acute MI, uptake of ultrasmall superparamagnetic particles of iron oxide occurs with the infarcted and remote myocardium. This technique holds major promise as a potential method for assessing cellular myocardial inflammation and left ventricular remodelling, which may have a range of applications in patients with MI and other inflammatory cardiac conditions. Clinical Trial Registration— URL: . Unique identifier: [NCT01323296][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01323296&atom=%2Fcirccvim%2F5%2F5%2F559.atom

Predictors for neoatherosclerosis: a retrospective observational study from the optical coherence tomography registry.

Abstract: Background Recent studies have reported development of neoatherosclerosis (NA) inside the stents several years after stent implantation. The aim of this study was to determine the predictors for NA using optical coherence tomography. Methods and results From a total of 1080 patients who underwent optical coherence tomography, we identified 179 stents in 151 patients in which the mean neointimal thickness was >100 µm. The presence of lipid-laden neointima or calcification inside the stents was defined as NA in the present study. Patient characteristics, stent type, and time since stent implantation (stent age) were compared between stents with or without NA. Univariable and multivariable logistic regression analyses were used to assess the independent predictors. In univariate analysis, stent age ≥48 months (Odds ratio [OR], 4.48; [95% CI 2.68-9.65]; P Conclusions In addition to the stent type and the stent age, patient characteristics, including current smoking, chronic kidney disease, and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockade, were associated with the presence of NA. This result may support the importance of secondary prevention after stent implantation.

Prevalence and clinical profile of myocardial crypts in hypertrophic cardiomyopathy.

Abstract: Background— In hypertrophic cardiomyopathy (HCM), cardiovascular MR can detect morphological abnormalities of the left ventricle (LV) not visualized with echocardiography. Although myocardial crypts (ie, narrow, blood-filled invaginations within the LV wall) have been recognized in HCM, all clinical implications of these structural abnormalities within the broad clinical HCM spectrum are not completely resolved. Therefore, we sought to characterize the prevalence and diagnostic significance of myocardial crypts in HCM patients. Methods and Results— Cine and late gadolinium enhancement cardiovascular MR and 2-dimensional echocardiography were obtained in 292 consecutive patients with HCM including 31 genotype-positive/phenotype-negative family members without LV hypertrophy (28 ± 16 years; 51% male) and 261 patients with LV hypertrophy (46 ± 18 years; 60% male). Ninety-eight subjects without cardiovascular disease were controls. Myocardial crypts (1–6/patient) were identified only by cardiovascular MR in 19 of 31 genotype-positive/phenotype-negative patients (61%) compared with only 10 of 261 (4%) patients with HCM with LV hypertrophy ( P <0.001) and were absent in control subjects. Twelve-lead electrocardiograms were normal in 10 (53%) of the genotype-positive/phenotype-negative patients with crypts. Crypts were confined to the basal LV, most commonly in the ventricular septum (n=21) or posterior LV free wall (n=4), and associated with normal LV contractility and absence of late gadolinium enhancement in all but one patient. Conclusions— LV myocardial crypts represent a distinctive morphological expression of HCM, occurring with different frequency in HCM patients with or without LV hypertrophy. Crypts are a novel cardiovascular MR imaging marker, which may identify individual HCM family members who should also be considered for diagnostic genetic testing. These data support an expanded role for cardiovascular MR in early evaluation of HCM families.

Quantifying pulmonary regurgitation and right ventricular function in surgically repaired tetralogy of Fallot: a comparative analysis of echocardiography and magnetic resonance imaging.

Abstract: Background— Patients with repaired tetralogy of Fallot are monitored for pulmonary regurgitation (PR) and right ventricular (RV) function. We sought to compare measures of PR and RV function on echocardiogram to those on cardiac magnetic resonance (CMR) and to develop a new tool for assessing PR by echocardiogram. Methods and Results— Patients with repaired tetralogy of Fallot (n=143; 12.5±3.2 years) had an echocardiogram and CMR within 3 months of each other. On echocardiogram, RV function was assessed by (1) Doppler tissue imaging of the RV free wall and (2) myocardial performance index. The ratio of diastolic and systolic time-velocity integrals measured by Doppler of the main pulmonary artery was calculated. CMR variables included RV ejection fraction, RV volumes, and pulmonary regurgitant fraction (RF). Pulmonary regurgitation was graded as mild (RF 40%). On CMR, RF was 34+17% and RV ejection fraction was 61+8%. Echocardiography had good sensitivity identifying cases with RF>20% (sensitivity 97%; 95% CI: 92–99%) but overestimated the amount of PR when RF<20% (false-positive rate 36%; 95% CI: 18–57%). The diastolic and systolic time-velocity integrals on echocardiogram showed moderate correlation with RF on CMR ( R =0.60; P <0.0001). On CMR, RF of 20% and 40% corresponded with a diastolic and systolic time-velocity integral of 0.49 (95% CI: 0.44–0.56) and 0.72 (95% CI: 0.68–0.76), respectively. RV myocardial performance index correlated modestly with RV ejection fraction ( r =−0.33; P <0.001). Conclusions— This study suggests that the diastolic and systolic time-velocity integrals ratio may make a modest contribution to the overall assessment of PR in patients with repaired tetralogy of Fallot and warrants further investigation. However, echocardiography continues to have a limited ability to quantify PR and RV function as compared with CMR.

Global strain in severe aortic valve stenosis: relation to clinical outcome after aortic valve replacement.

Abstract: Background— Global longitudinal systolic strain (GLS) is often reduced in aortic stenosis despite normal ejection fraction. The importance of reduced preoperative GLS on long-term outcome after aortic valve replacement is unknown. Methods and Results— A total of 125 patients with severe aortic stenosis and ejection fraction >40% scheduled for aortic valve replacement were evaluated preoperatively and divided into 4 groups according to GLS quartiles. Patients were followed up for 4 years. The primary end points were major adverse cardiac events (MACEs) defined as cardiovascular mortality and cardiac hospitalization because of worsening of heart failure; the secondary end point was cardiovascular mortality. MACE and cardiac mortality were significantly increased in patients with lower GLS. Estimated 5-year MACE was increased: first quartile 19% (n=6) / second quartile 20% (n=6) / third quartile 35% (n=11) / fourth quartile 49% (n=15); P =0.04. Patients with increased age, left ventricular hypertrophy, and left atrial dilatation were at increased risk. In Cox regression analysis, after correcting for standard risk factors and ejection fraction, GLS was found to be significantly associated with cardiac morbidity and mortality. In a stepwise Cox model with forward selection, GLS was the sole independent predictor: hazard ratio=1.13 (95% confidence interval, 1.02–1.25), P =0.04. Comparing the overall log likelihood χ2 of the predictive power of the multivariable model containing GLS was statistically superior to models based on EuroScore, history with ischemic heart disease, and ejection fraction. Conclusions— In patients with symptomatic severe aortic stenosis undergoing aortic valve replacement, reduced GLS provides important prognostic information beyond standard risk factors. Clinical Trial Registration— URL: [http://www.clinicaltrials.gov][1]. Unique identifier: [NCT00294775][2]. [1]: http://www.clinicaltrial.gov [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00294775&atom=%2Fcirccvim%2F5%2F5%2F613.atom

Assessment of skin microvascular function and dysfunction with laser speckle contrast imaging.

Abstract: In recent years, skin microcirculation has been considered an easily accessible and potentially representative vascular bed to evaluate and understand the mechanisms of microvascular function and dysfunction.1–3 Vascular dysfunction (including impaired endothelium-dependent vasodilation) induced by different pathologies is evident in the cutaneous circulation.4–7 It has been suggested that the skin microcirculation may mirror generalized systemic vascular dysfunction in magnitude and underlying mechanisms.1 Furthermore, minimally invasive skin-specific methodologies using laser systems make the cutaneous circulation a useful translational model for investigating mechanisms of skin physiology and skin pathophysiology induced either by skin disease itself or by other diseases such as vascular, rheumatologic, and pneumologic. To date, the skin has been used as a circulation model to investigate vascular mechanisms in a variety of diseased states, including hypercholesterolemia,8 Alzheimer disease,9 carpal tunnel syndrome,10 schizophrenia,11 hypertension,6 renal disease,12 type 2 diabetes,13 peripheral vascular disease,14 atherosclerotic coronary artery disease,2 heart failure,15 systemic sclerosis,16 obesity,17 primary aging,18,19 and sleep apnea.20 Assessment of skin microvascular function can be done by both invasive and noninvasive techniques. Among noninvasive techniques, laser systems are mainly used.21 The recent development of the laser speckle contrast imaging (LSCI) technique for monitoring skin microvascular function enables its use as a surrogate end point in clinical trials. LSCI allows for noncontact, real-time, and noninvasive monitoring of cutaneous blood flow changes.22,23 Recent evidence has shown that the LSCI technique dramatically reduces the variability of clinical measurements compared with laser Doppler flowmetry (LDF), making the technique a fascinating tool to facilitate microvascular studies in clinical routine.23,24 In this review, we describe …

Association between diffuse myocardial fibrosis by cardiac magnetic resonance contrast-enhanced T₁ mapping and subclinical myocardial dysfunction in diabetic patients: a pilot study.

Abstract: Background— Diabetic patients have increased interstitial myocardial fibrosis on histological examination. Magnetic resonance imaging (MRI) T1 mapping is a previously validated imaging technique that can quantify the burden of global and regional interstitial fibrosis. However, the association between MRI T1 mapping and subtle left ventricular (LV) dysfunction in diabetic patients is unknown. Methods and Results— Fifty diabetic patients with normal LV ejection fraction (EF) and no underlying coronary artery disease or regional macroscopic scar on MRI delayed enhancement were prospectively recruited. Diabetic patients were compared with 19 healthy controls who were frequency matched in age, sex and body mass index. There were no significant differences in mean LV end-diastolic volume index, end-systolic volume index and LVEF between diabetic patients and healthy controls. Diabetic patients had significantly shorter global contrast-enhanced myocardial T1 time (425±72 ms vs. 504±34 ms, P <0.001). There was no correlation between global contrast-enhanced myocardial T1 time and LVEF ( r =0.14, P =0.32) in the diabetic patients. However, there was good correlation between global contrast-enhanced myocardial T1 time and global longitudinal strain ( r =−0.73, P <0.001). Global contrast-enhanced myocardial T1 time was the strongest independent determinant of global longitudinal strain on multivariate analysis (standardized β=−0.626, P <0.001). Similarly, there was good correlation between global contrast-enhanced myocardial T1 time and septal E′ ( r =0.54, P <0.001). Global contrast-enhanced myocardial T1 time was also the strongest independent determinant of septal E′ (standardized β=0.432, P <0.001). Conclusions— A shorter global contrast-enhanced myocardial T1 time was associated with more impaired longitudinal myocardial systolic and diastolic function in diabetic patients.

Normal left ventricular myocardial thickness for middle-aged and older subjects with steady-state free precession cardiac magnetic resonance: the multi-ethnic study of atherosclerosis.

Abstract: Background— Increased left ventricular myocardial thickness (LVMT) is a feature of several cardiac diseases. The purpose of this study was to establish standard reference values of normal LVMT with cardiac magnetic resonance and to assess variation with image acquisition plane, demographics, and left ventricular function. Methods and Results— End-diastolic LVMT was measured on cardiac magnetic resonance steady-state free precession cine long and short axis images in 300 consecutive participants free of cardiac disease (169 women; 65.6±8.5 years) of the Multi-Ethnic Study of Atherosclerosis cohort. Mean LVMT on short axis images at the mid-cavity level was 5.3±0.9 mm and 6.3±1.1 mm for women and men, respectively. The average of the maximum LVMT at the mid-cavity for women/men was 7/9 mm (long axis) and 7/8 mm (short axis). Mean LVMT was positively associated with weight (0.02 mm/kg; P =0.01) and body surface area (1.1 mm/m2; P <0.001). No relationship was found between mean LVMT and age or height. Greater mean LVMT was associated with lower left ventricular end-diastolic volume (0.01 mm/mL; P <0.01), a lower left ventricular end-systolic volume (−0.01 mm/mL; P =0.01), and lower left ventricular stroke volume (−0.01 mm/mL; P <0.05). LVMT measured on long axis images at the basal and mid-cavity level were slightly greater (by 6% and 10%, respectively) than measurements obtained on short axis images; apical LVMT values on long axis images were 20% less than those on short axis images. Conclusions— Normal values for wall thickness are provided for middle-aged and older subjects. Normal LVMT is lower for women than men. Observed values vary depending on the imaging plane for measurement.

A Simple Echocardiographic Prediction Rule for Hemodynamics in Pulmonary Hypertension

Abstract: Background— Pulmonary hypertension (PH) has diverse causes with heterogeneous physiology compelling distinct management. Differentiating patients with primarily elevated pulmonary vascular resistance (PVR) from those with PH predominantly because of elevated left-sided filling pressure is critical. Methods and Results— We reviewed hemodynamics, echocardiography, and clinical data for 108 patients seen at a referral PH clinic with transthoracic echocardiogram and right heart catheterization within 1 year. We derived a simple echocardiographic prediction rule to allow hemodynamic differentiation of PH attributed to pulmonary vascular disease (PHPVD, defined as pulmonary artery wedge pressure [PAWP]≤15 mm Hg and PVR>3 WU). Age averaged 61.3±14.8 years, μPAWP and PVR were 16.4±7.1 mm Hg and 6.3±4.0 WU, respectively, and 52 (48.1%) patients fulfilled PHPVD hemodynamic criteria. The derived prediction rule ranged from –2 to +2 with higher scores suggesting higher probability of PHPVD: +1 point for left atrial anterior–posterior dimension 10; –1 for left atrial anterior-posterior dimension >4.2 cm. PVR increased stepwise with score (for –2, 0, and +2, μPVR were 2.5, 4.5, and 8.1 WU, respectively), whereas the inverse was true for pulmonary artery wedge pressure (corresponding μPAWP were 21.5, 16.5, and 10.4 mm Hg). Among subjects with complete data, the score had an area under the curve (AUC) of 0.921 for PHPVD. A score ≥0 had 100% sensitivity and 69.3% positive predictive value for PHPVD, with 62.3% specificity. No patients with a negative score had PHPVD. Patients with a negative score and acceleration time >100 ms had normal PVR (μPVR=1.8 WU, range=0.7–3.2 WU). Conclusions— We present a simple echocardiographic prediction rule that accurately defines PH hemodynamics, facilitates improved screening and focused clinical investigation for PH diagnosis and management.

Characterizing Myocardial Edema and Hemorrhage Using Quantitative T2 and T2* Mapping at Multiple Time Intervals Post ST-Segment Elevation Myocardial Infarction

Abstract: Background—Accurate characterization of the longitudinal trends of myocardial edema and hemorrhage has been previously limited by subjective qualitative methods. We aimed to prospectively character...

Multimodality imaging of lower extremity peripheral arterial disease: current role and future directions.

Abstract: Patients with symptomatic peripheral arterial disease (PAD) affecting the lower extremities are initially evaluated with an ankle-brachial index (ABI) and segmental pressure measurements. An ABI 50% stenosis) with a sensitivity and specificity of 79% and 96%, respectively.1 An ABI between 0.90 and 1.0 is considered borderline. The localization of the stenosis can be inferred by an abnormal decrease (>20 mm Hg) in segmental lower extremity pressures. In the presence of calcified atherosclerosis, arteries may become stiff and noncompressible, which results in a falsely elevated ABI (often >1.3). For patients with suspected PAD and a normal ABI at rest, it is valuable to obtain postexercise ABI measurements, which if <0.85 are consistent with PAD and is an independent predictor of mortality.2 Imaging is then needed to confirm the location and degree of stenosis before revascularization or if the diagnosis of PAD is uncertain. Characterization of PAD can be performed with noninvasive angiography using computed tomography (CTA) or magnetic resonance angiography (MRA), as well as with duplex ultrasonography (US), depending on patient specific characteristics (Table 1). Advances in both CTA and MRA provide clinicians with the opportunity to obtain a high resolution, 3-dimensional (3-D) road map of the peripheral arterial tree in patients, particularly when planning revascularization strategies. Invasive digital subtraction angiography (DSA) has been the accepted standard for evaluation of lower extremity atherosclerosis. Although DSA is a robust technique for diagnosing significant arterial stenosis or obstruction, it provides a 2-D view of the vessels, which may underestimate the degree of stenosis for tortuous vessels.3 Furthermore, there are inherent risks with arterial access, ionizing radiation, and the use of iodinated contrast media (CM).4 View this table: Table 1. Comparison Between CTA, MRA, and Duplex US for Diagnosis of PAD This review aims to deliver a comprehensive, yet concise …

Utility of Cardiovascular Magnetic Resonance in Identifying Substrate for Malignant Ventricular Arrhythmias

Abstract: Background— Sudden cardiac death (SCD) and sustained monomorphic ventricular tachycardia (SMVT) are frequently associated with prior or acute myocardial injury Cardiovascular magnetic resonance (CMR) provides morphological, functional, and tissue characterization in a single setting We sought to evaluate the diagnostic yield of CMR-based imaging versus non–CMR-based imaging in patients with resuscitated SCD or SMVT Methods and Results— Eighty-two patients with resuscitated SCD or SMVT underwent routine non-CMR imaging, followed by a CMR protocol with comprehensive tissue characterization Clinical reports of non-CMR imaging studies were blindly adjudicated and used to assign each patient to 1 of 7 diagnostic categories CMR imaging was blindly interpreted using a standardized algorithm used to assign a patient diagnosis category in a similar fashion The diagnostic yield of CMR-based and non–CMR-based imaging, as well as the impact of the former on diagnosis reclassification, was established Relevant myocardial disease was identified in 51% of patients using non–CMR-based imaging and in 74% using CMR-based imaging ( P =0002) Forty-one patients (50%) were reassigned to a new or alternate diagnosis using CMR-based imaging, including 15 (18%) with unsuspected acute myocardial injury Twenty patients (24%) had no abnormality by non-CMR imaging but showed clinically relevant myocardial disease by CMR imaging Conclusions— CMR-based imaging provides a robust diagnostic yield in patients presenting with resuscitated SCD or SMVT and incrementally identifies clinically unsuspected acute myocardial injury When compared with non–CMR-based imaging, a new or alternate myocardial disease process may be identified in half of these patients