Showing papers in "Circulation in 2009"
TL;DR: It was agreed that there should not be an obligatory component, but that waist measurement would continue to be a useful preliminary screening tool, and a single set of cut points would be used for all components except waist circumference, for which further work is required.
Abstract: A cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus, which occur together more often than by chance alone, have become known as the metabolic syndrome. The risk factors include raised blood pressure, dyslipidemia (raised triglycerides and lowered high-density lipoprotein cholesterol), raised fasting glucose, and central obesity. Various diagnostic criteria have been proposed by different organizations over the past decade. Most recently, these have come from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. The main difference concerns the measure for central obesity, with this being an obligatory component in the International Diabetes Federation definition, lower than in the American Heart Association/National Heart, Lung, and Blood Institute criteria, and ethnic specific. The present article represents the outcome of a meeting between several major organizations in an attempt to unify criteria. It was agreed that there should not be an obligatory component, but that waist measurement would continue to be a useful preliminary screening tool. Three abnormal findings out of 5 would qualify a person for the metabolic syndrome. A single set of cut points would be used for all components except waist circumference, for which further work is required. In the interim, national or regional cut points for waist circumference can be used.
11,737 citations
TL;DR: The statistical update brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update.
Abstract: We thank Drs Sean Coady, Eric L. Ding, Brian Eigel, Gregg C. Fonarow, Linda Geiss, Cherie James, Michael Mussolino, and Michael Wolz for their valuable comments and contributions. We acknowledge Tim Anderson and Tom Schneider for their editorial contributions, and Karen Modesitt for her administrative assistance.
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# Summary {#article-title-2}
Each year, the American Heart Association, in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay …
5,019 citations
TL;DR: The statistical update brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update.
Abstract: We thank Drs Sean Coady, Eric L. Ding, Brian Eigel, Gregg C. Fonarow, Linda Geiss, Cherie James, Michael Mussolino, and Michael Wolz for their valuable comments and contributions. We acknowledge Tim Anderson and Tom Schneider for their editorial contributions, and Karen Modesitt for her administrative assistance.
Disclosures
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Writing Group Disclosures
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# Summary {#article-title-2}
Each year, the American Heart Association, in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay …
4,003 citations
TL;DR: Theodore G. Feldman, MD, PhD, FACC, FAHA, Chair as mentioned in this paper, Chair, Chair of FAHA 2015, 2016, 2017, 2018, 2019, 2019
Abstract: Mariell Jessup, MD, FACC, FAHA, Chair [*][1]
William T. Abraham, MD, FACC, FAHA[†][2]
Donald E. Casey, MD, MPH, MBA[‡][3]
Arthur M. Feldman, MD, PhD, FACC, FAHA[§][4]
Gary S. Francis, MD, FACC, FAHA[§][4]
Theodore G. Ganiats, MD[∥][5]
Marvin A. Konstam, MD, FACC[¶][6]
Donna M.
3,542 citations
TL;DR: In this national registry, the absolute number of cardiovascular sudden deaths in young US athletes was somewhat higher than previous estimates but relatively low nevertheless, with a rate of <100 per year.
Abstract: Background— Sudden deaths in young competitive athletes are highly visible events with substantial impact on the physician and lay communities. However, the magnitude of this public health issue has become a source of controversy. Methods and Results— To estimate the absolute number of sudden deaths in US competitive athletes, we have assembled a large registry over a 27-year period using systematic identification and tracking strategies. A total of 1866 athletes who died suddenly (or survived cardiac arrest), 19±6 years of age, were identified throughout the United States from 1980 to 2006 in 38 diverse sports. Reports were less common during 1980 to 1993 (576 [31%]) than during 1994 to 2006 (1290 [69%], P<0.001) and increased at a rate of 6% per year. Sudden deaths were predominantly due to cardiovascular disease (1049 [56%]), but causes also included blunt trauma that caused structural damage (416 [22%]), commotio cordis (65 [3%]), and heat stroke (46 [2%]). Among the 1049 cardiovascular deaths, the hi...
1,655 citations
TL;DR: The goals of the present report are to address different methods of measuring adherence, the prevalence of medicationNonadherence, the association between nonadherence and outcomes, the reasons for nonad adherence, and finally, interventions to improve medication adherence.
Abstract: Medication adherence usually refers to whether patients take their medications as prescribed (eg, twice daily), as well as whether they continue to take a prescribed medication. Medication nonadherence is a growing concern to clinicians, healthcare systems, and other stakeholders (eg, payers) because of mounting evidence that it is prevalent and associated with adverse outcomes and higher costs of care. To date, measurement of patient medication adherence and use of interventions to improve adherence are rare in routine clinical practice. The goals of the present report are to address (1) different methods of measuring adherence, (2) the prevalence of medication nonadherence, (3) the association between nonadherence and outcomes, (4) the reasons for nonadherence, and finally, (5) interventions to improve medication adherence.
1,394 citations
TL;DR: The 2009 Focused Update: ACCF/AHA Guidelines for the Diagnosis and This information is current as of August 30, 2010 http://content.onlinejacc.org/cgi/content/full/53/15/1343 located on the World Wide Web at: The online version of this article, along with updated information and services, is
Abstract: 2009;53;1343-1382; originally published online Mar 26, 2009; J. Am. Coll. Cardiol. Rahko, Marc A. Silver, Lynne Warner Stevenson, and Clyde W. Yancy Francis, Theodore G. Ganiats, Marvin A. Konstam, Donna M. Mancini, Peter S. Mariell Jessup, William T. Abraham, Donald E. Casey, Arthur M. Feldman, Gary S. Heart and Lung Transplantation Developed in Collaboration With the International Society for Guidelines Cardiology Foundation/American Heart Association Task Force on Practice Management of Heart Failure in Adults: A Report of the American College of 2009 Focused Update: ACCF/AHA Guidelines for the Diagnosis and This information is current as of August 30, 2010 http://content.onlinejacc.org/cgi/content/full/53/15/1343 located on the World Wide Web at: The online version of this article, along with updated information and services, is
1,201 citations
TL;DR: Evidence from observational studies indicates that a higher intake of soft drinks is associated with greater energy intake, higher body weight, and lower intake of essential nutrients, and national survey data indicate that excessive consumption of added sugars is contributing to overconsumption of discretionary calories by Americans.
Abstract: High intakes of dietary sugars in the setting of a worldwide pandemic of obesity and cardiovascular disease have heightened concerns about the adverse effects of excessive consumption of sugars. In 2001 to 2004, the usual intake of added sugars for Americans was 22.2 teaspoons per day (355 calories per day). Between 1970 and 2005, average annual availability of sugars/added sugars increased by 19%, which added 76 calories to Americans' average daily energy intake. Soft drinks and other sugar-sweetened beverages are the primary source of added sugars in Americans' diets. Excessive consumption of sugars has been linked with several metabolic abnormalities and adverse health conditions, as well as shortfalls of essential nutrients. Although trial data are limited, evidence from observational studies indicates that a higher intake of soft drinks is associated with greater energy intake, higher body weight, and lower intake of essential nutrients. National survey data also indicate that excessive consumption of added sugars is contributing to overconsumption of discretionary calories by Americans. On the basis of the 2005 US Dietary Guidelines, intake of added sugars greatly exceeds discretionary calorie allowances, regardless of energy needs. In view of these considerations, the American Heart Association recommends reductions in the intake of added sugars. A prudent upper limit of intake is half of the discretionary calorie allowance, which for most American women is no more than 100 calories per day and for most American men is no more than 150 calories per day from added sugars. (Circulation. 2009; 120:1011-1020.)
1,178 citations
TL;DR: In general, a novel risk marker should be evaluated in several phases, including initial proof of concept, prospective validation in independent populations, documentation of incremental information when added to standard risk markers, assessment of effects on patient management and outcomes, and ultimately, cost-effectiveness.
Abstract: There is increasing interest in utilizing novel markers of cardiovascular disease risk, and consequently, there is a need to assess the value of their use. This scientific statement reviews current concepts of risk evaluation and proposes standards for the critical appraisal of risk assessment methods. An adequate evaluation of a novel risk marker requires a sound research design, a representative at-risk population, and an adequate number of outcome events. Studies of a novel marker should report the degree to which it adds to the prognostic information provided by standard risk markers. No single statistical measure provides all the information needed to assess a novel marker, so measures of both discrimination and accuracy should be reported. The clinical value of a marker should be assessed by its effect on patient management and outcomes. In general, a novel risk marker should be evaluated in several phases, including initial proof of concept, prospective validation in independent populations, documentation of incremental information when added to standard risk markers, assessment of effects on patient management and outcomes, and ultimately, cost-effectiveness.
1,070 citations
TL;DR: Ticagrelor achieved more rapid and greater platelet inhibition than high-loading-dose clopidogrel; this was sustained during the maintenance phase and was faster in offset after drug discontinuation.
Abstract: Background— Ticagrelor is the first reversibly binding oral P2Y 12 receptor antagonist. This is the first study to compare the onset and offset of platelet inhibition (IPA) with ticagrelor using the PLATO (PLATelet inhibition and patient Outcomes) trial loading dose (180 mg) with a high loading dose (600 mg) of clopidogrel. Methods and Results— In a multicenter, randomized, double-blind study, 123 patients with stable coronary artery disease who were taking aspirin therapy (75 to 100 mg/d) received ticagrelor (180-mg load, 90-mg BID maintenance dose [n=57]), clopidogrel (600-mg load, 75-mg/d maintenance dose [n=54]), or placebo (n=12) for 6 weeks. Greater IPA (20 μmol/L ADP, final extent) occurred with ticagrelor than with clopidogrel at 0.5, 1, 2, 4, 8, and 24 hours after loading and at 6 weeks ( P 50% IPA (98% versus 31%, P 70% IPA (90% versus 16%, P P P =NS). IPA for ticagrelor on day 3 after the last dose was comparable to clopidogrel at day 5; IPA on day 5 for ticagrelor was similar to clopidogrel on day 7 and did not differ from placebo ( P =NS). Conclusions— Ticagrelor achieved more rapid and greater platelet inhibition than high-loading-dose clopidogrel; this was sustained during the maintenance phase and was faster in offset after drug discontinuation. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00528411.
1,019 citations
TL;DR: The situations in which qualitative approaches are most helpful are described and the primary principles and practices in study design, sampling, data collection, and data analysis for qualitative studies are summarized to synthesize current standards for qualitative research methods.
Abstract: Outcomes research examines the effects of medical care interventions and policies on the health outcomes of individuals and society.1 Investigators conducting outcomes research seek to inform the development of clinical practice guidelines, to evaluate the quality of medical care, and to foster effective interventions to improve the quality of care.2 Outcomes research has traditionally used quantitative sciences to examine the utilization, cost, and clinical effectiveness of medical care through randomized and nonrandomized experimental designs. Quantitative methods are not as well suited to measure other complex aspects of the healthcare delivery system, such as organizational change, clinical leadership in implementing evidence-based guidelines, and patient perceptions of quality of care, which are also critical issues in outcomes research.3–7 These more nuanced aspects of healthcare delivery may be most appropriately examined with qualitative research methods.8–10
Qualitative approaches are becoming more common in clinical medicine and health services research.5,11–15 Federal encouragement of qualitative research is regularly reflected in funding program announcements issued by the National Institutes of Health.16 For more than a decade, federal agencies and foundations such as the National Science Foundation have demonstrated a commitment to supporting qualitative research through funding scientific conferences, workshops, and monographs on this field of inquiry.17–20 Despite this steady growth in qualitative research, outcomes investigators in cardiology have relatively little guidance on when and how best to implement these methods in their investigations.
The purpose of the present report is to introduce qualitative methods as providing unique and critical contributions to outcomes research. This report will describe the situations in which qualitative approaches are most helpful; summarize the primary principles and practices in study design, sampling, data collection, and data analysis for qualitative studies; present representative examples of cardiovascular outcomes research that uses qualitative methods; and synthesize current standards for …
TL;DR: This scientific statement seeks to highlight concepts and evidence important to the understanding and promotion of self-care in persons with HF, and describes what is known about the self- Care behaviors required of HF patients, and the effect ofSelf-care on HF outcomes.
Abstract: Self-care is advocated as a method of improving outcomes from heart failure (HF), the final common pathway for several prevalent illnesses, including hypertension and coronary artery disease. HF is widespread in aging populations across the world.1 The burden of HF is manifested in poor quality of life (QOL)2,3 and early mortality.4 In addition, there are >3 million ambulatory care and emergency department visits5 and well over 1 million hospitalizations for HF in the United States annually,6 which contributes to the exorbitant costs associated with HF. Much of this healthcare utilization is thought to be preventable if patients engage in consistent self-care.7,8
This scientific statement seeks to highlight concepts and evidence important to the understanding and promotion of self-care in persons with HF. Specifically, the document describes what is known about (1) the self-care behaviors required of HF patients, (2) factors that make self-care challenging for patients, (3) interventions that promote self-care, and (4) the effect of self-care on HF outcomes. The review ends with evidence-based recommendations for clinicians and direction for future research.
Self-care is defined as a naturalistic decision-making process that patients use in the choice of behaviors that maintain physiological stability (symptom monitoring and treatment adherence) and the response to symptoms when they occur.9 The term naturalistic decision making is used to describe how people make decisions in real-world settings. Naturalistic decision makers focus on process rather than outcomes, make decisions based on the situation, let the context influence their decision-making processes, and base practical decisions on the information available at the moment.10
In HF, self-care maintenance requires following the advice of providers to take medications, eat a low-sodium diet, exercise, engage in preventive behaviors, and actively monitor themselves for signs and symptoms. Self-care management refers to decision making in …
TL;DR: The utility of delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome is reported and may provide insight into the progress of the disease.
Abstract: Background— Atrial fibrillation (AF) is associated with diffuse left atrial fibrosis and a reduction in endocardial voltage. These changes are indicators of AF severity and appear to be predictors of treatment outcome. In this study, we report the utility of delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome. Methods and Results— Eighty-one patients presenting for pulmonary vein antrum isolation for treatment of AF underwent 3-dimensional DE-MRI of the left atrium before the ablation. Six healthy volunteers also were scanned. DE-MRI images were manually segmented to isolate the left atrium, and custom software was implemented to quantify the spatial extent of delayed enhancement, which was then compared with the regions of low voltage from electroanatomic maps from the pulmonary vein antrum isolation procedure. Patients were assessed for AF recurrence at least 6 months after pulmonary vein antrum i...
TL;DR: In patients with pulmonary arterial hypertension, tadalafil 40 mg was well tolerated and improved exercise capacity and quality of life measures and reduced clinical worsening.
Abstract: Background— Treatment options for pulmonary arterial hypertension target the prostacyclin, endothelin, or nitric oxide pathways. Tadalafil, a phosphodiesterase type-5 inhibitor, increases cGMP, the final mediator in the nitric oxide pathway. Methods and Results— In this 16-week, double-blind, placebo-controlled study, 405 patients with pulmonary arterial hypertension (idiopathic or associated), either treatment-naive or on background therapy with the endothelin receptor antagonist bosentan, were randomized to placebo or tadalafil 2.5, 10, 20, or 40 mg orally once daily. The primary end point was the change from baseline to week 16 in the distance walked in 6 minutes. Changes in World Health Organization functional class, clinical worsening, and health-related quality of life were also assessed. Patients completing the 16-week study could enter a long-term extension study. Tadalafil increased the distance walked in 6 minutes in a dose-dependent manner; only the 40-mg dose met the prespecified level of statistical significance ( P P =0.041), incidence of clinical worsening (68% relative risk reduction; P =0.038), and health-related quality of life. The changes in World Health Organization functional class were not statistically significant. The most common treatment-related adverse events reported with tadalafil were headache, myalgia, and flushing. Conclusions— In patients with pulmonary arterial hypertension, tadalafil 40 mg was well tolerated and improved exercise capacity and quality of life measures and reduced clinical worsening.
TL;DR: The Expert Consensus Document (ECD) as mentioned in this paper was developed by the American College of Cardiology Foundation (ACCF) Task Task Task Force on Consensus Documents (ECDs) and was cosponsored by AHA.
Abstract: This document has been developed by the American College of Cardiology Foundation (ACCF) Task Force on Expert Consensus Documents (ECDs), and was cosponsored by the American Heart Association (AHA). Expert Consensus Documents are intended to inform practitioners and other interested parties of the
TL;DR: The CRUSADE bleeding score quantifies risk for in-hospital major bleeding across all postadmission treatments, which enhances baseline risk assessment for NSTEMI care.
Abstract: Background— Treatments for non–ST-segment–elevation myocardial infarction (NSTEMI) reduce ischemic events but increase bleeding. Baseline prediction of bleeding risk can complement ischemic risk pr...
TL;DR: This study provides the first data-based estimate of the prevalence of LQTS among whites and advances the hypothesis that this prevalence might be close to 1:2000, thus allowing effective preventive measures.
Abstract: Background— The prevalence of genetic arrhythmogenic diseases is unknown. For the long-QT syndrome (LQTS), figures ranging from 1:20 000 to 1:5000 were published, but none was based on actual data. Our objective was to define the prevalence of LQTS. Methods and Results— In 18 maternity hospitals, an ECG was performed in 44 596 infants 15 to 25 days old (43 080 whites). In infants with a corrected QT interval (QTc) >450 ms, the ECG was repeated within 1 to 2 weeks. Genetic analysis, by screening 7 LQTS genes, was performed in 28 of 31 (90%) and in 14 of 28 infants (50%) with, respectively, a QTc >470 ms or between 461 and 470 ms. A QTc of 451 to 460, 461 to 470, and >470 ms was observed in 177 (0.41%), 28 (0.06%), and 31 infants (0.07%). Among genotyped infants, disease-causing mutations were found in 12 of 28 (43%) with a QTc >470 ms and in 4 of 14 (29%) with a QTc of 461 to 470 ms. One genotype-negative infant (QTc 482 ms) was diagnosed as affected by LQTS on clinical grounds. Among family members of gen...
TL;DR: Brachial artery flow-mediated dilation is a predictor of incident cardiovascular events in population-based adults and improved the classification of subjects as low, intermediate, and high CVD risk compared with the FRS.
Abstract: Background— Although brachial artery flow-mediated dilation (FMD) predicts recurrent cardiovascular events, its predictive value for incident cardiovascular disease (CVD) events in adults free of CVD is not well established. We assessed the predictive value of FMD for incident CVD events in the Multi-Ethnic Study of Atherosclerosis (MESA). Methods and Results— Brachial artery FMD was measured in a nested case-cohort sample of 3026 of 6814 subjects (mean±SD age, 61.2±9.9 years) in MESA, a population-based cohort study of adults free of clinical CVD at baseline recruited at 6 clinic sites in the United States. The sample included 50.2% female, 34.3% white, 19.7% Chinese, 20.8% black, and 25.1% Hispanic subjects. Probability-weighted Cox proportional hazards analysis was used to examine the association between FMD and 5 years of adjudicated incident CVD events, including incident myocardial infarction, definite angina, coronary revascularization (coronary artery bypass grafting, percutaneous transluminal cor...
TL;DR: The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery, so improved renal protection and closer postdischarge follow-up of renal function may be warranted.
Abstract: Background—Long-term survival after acute kidney injury (AKI) is poorly studied. We report the relationship between long-term mortality and AKI with small changes in serum creatinine during hospitalization after various cardiothoracic surgery procedures. Methods and Results—This was a retrospective study of 2973 patients with no history of chronic kidney disease who were discharged from the hospital after cardiothoracic surgery between 1992 and 2002. AKI was defined by the RIFLE classification (Risk, Injury, Failure, Loss, and End stage), which requires at least a 50% increase in serum creatinine and stratifies patients into 3 grades of AKI: Risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed with a risk-adjusted Cox proportional hazards regression model. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio of 1.23 (95% CI 1.06 to 1.42) for the least severe RIFLE risk class and 2.14 (95% CI 1.73 to 2.66) for the RIFLE failure class compared with patients without AKI. Survival was worse among all subgroups of cardiothoracic surgery with AKI except for valve surgery. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.28 (95% CI 1.11 to 1.48) compared with patients without AKI. Conclusions—The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery. Improved renal protection and closer postdischarge follow-up of renal function may be warranted. (Circulation. 2009;119:2444-2453.)
TL;DR: FGF-23 is independently associated withleft ventricular mass index and left ventricular hypertrophy in patients with CKD, and whether increased FGF- 23 is a marker or a potential mechanism of myocardial hyperTrophy in CKD requires further study.
Abstract: Background— Fibroblast growth factor 23 (FGF-23) is a phosphorus-regulating hormone. In chronic kidney disease (CKD), circulating FGF-23 levels are markedly elevated and independently associated with mortality. Left ventricular hypertrophy and coronary artery calcification are potent risk factors for mortality in CKD, and FGFs have been implicated in the pathogenesis of both myocardial hypertrophy and atherosclerosis. We conducted a cross-sectional study to test the hypothesis that elevated FGF-23 concentrations are associated with left ventricular hypertrophy and coronary artery calcification in patients with CKD. Methods and Results— In this study, 162 subjects with CKD underwent echocardiograms and computed tomography scans to assess left ventricular mass index and coronary artery calcification; echocardiograms also were obtained in 58 subjects without CKD. In multivariable-adjusted regression analyses in the overall sample, increased log FGF-23 concentrations were independently associated with increas...
TL;DR: A greater adherence to the Mediterranean diet, as reflected by a higher Alternate Mediterranean Diet Score, was associated with a lower risk of incident CHD and stroke in women.
Abstract: Background— Several studies have documented an inverse association between adherence to the Mediterranean diet and risk of coronary heart disease (CHD), but few data are available on the relationsh...
TL;DR: In this paper, a modified Cox model that allows adjustment for competing risk of noncardiovascular death was used to construct a prediction algorithm for 30-year risk of hard CVD events (coronary death, myocardial infarction, stroke).
Abstract: Background— Present cardiovascular disease (CVD) risk prediction algorithms were developed for a ≤10-year follow up period. Clustering of risk factors at younger ages and increasing life expectancy suggest the need for longer-term risk prediction tools. Methods and Results— We prospectively followed 4506 participants (2333 women) of the Framingham Offspring cohort aged 20 to 59 years and free of CVD and cancer at baseline examination in 1971–1974 for the development of “hard” CVD events (coronary death, myocardial infarction, stroke). We used a modified Cox model that allows adjustment for competing risk of noncardiovascular death to construct a prediction algorithm for 30-year risk of hard CVD. Cross-validated survival C statistic and calibration χ2 were used to assess model performance. The 30-year hard CVD event rates adjusted for the competing risk of death were 7.6% for women and 18.3% for men. Standard risk factors (male sex, systolic blood pressure, antihypertensive treatment, total and high-densit...
TL;DR: The present article is the fourth in a series of 6 documents focused on providing current guidelines for the standardization and interpretation of the electrocardiogram (ECG) and explains why the ST and TP segments are normally nearly flat and at approximately the same level; that is, they are isoelectric.
Abstract: The present article is the fourth in a series of 6 documents focused on providing current guidelines for the standardization and interpretation of the electrocardiogram (ECG). The project was initiated by the Council on Clinical Cardiology of the American Heart Association. The rationale for this project and the process for its implementation were described earlier.1 Abnormalities in the ST segment, T wave, and duration of the QT interval reflect abnormalities in ventricular repolarization. These abnormalities are common and often difficult to interpret. The U wave most likely represents an electricmechanical phenomenon that occurs after repolarization is completed. However, it is frequently included in discussions of repolarization and is discussed in this section. The ST segment corresponds to the plateau phase of the ventricular transmembrane action potential. Under normal conditions, the transmembrane voltage changes slowly during this phase and remains at approximately the same level in all ventricular myocardial cells. As a result, only small voltage gradients are present. This absence of pronounced voltage gradients is similar to that which occurs during electric diastole, ie, from the end of repolarization to the onset of the next depolarization, when ventricular myocardial cells are at their resting transmembrane potential of approximately 85 mV. This corresponds to the TP segment on the ECG. The absence of significant voltage gradients in ventricular myocardial cells during these 2 phases of the cardiac cycle explains why the ST and TP segments are normally nearly flat and at approximately the same level; that is, they are isoelectric. The T wave corresponds to the phase of rapid ventricular repolarization (phase 3) of the ventricular action potential.
TL;DR: This advisory focuses primarily onLinoleic acid, an 18-carbon fatty acid with 2 double bonds, which accounts for 85% to 90% of the dietary omega-6 PUFA, recognizing that dietary AA, which can affect tissue AA levels,5 may have physiological sequelae.
Abstract: A large body of literature suggests that higher intakes of omega-6 (or n-6) polyunsaturated fatty acids (PUFAs) reduce risk for coronary heart disease (CHD). However, for the reasons outlined below, some individuals and groups have recommended substantial reductions in omega-6 PUFA intake.1–4 The purpose of this advisory is to review evidence on the relationship between omega-6 PUFAs and the risk of CHD and cardiovascular disease.
Omega-6 PUFAs are characterized by the presence of at least 2 carbon-carbon double bonds, with the first bond at the sixth carbon from the methyl terminus. Linoleic acid (LA), an 18-carbon fatty acid with 2 double bonds (18:2 omega-6), is the primary dietary omega-6 PUFA. LA cannot be synthesized by humans, and although firm minimum requirements have not been established for healthy adults, estimates derived from studies in infants and hospitalized patients receiving total parenteral nutrition suggest that an LA intake of ≈0.5% to 2% of energy is likely to suffice. After consumption, LA can be desaturated and elongated to form other omega-6 PUFAs such as γ-linolenic and dihomo-γ-linolenic acids. The latter is converted to the metabolically important omega-6 PUFA arachidonic acid (AA; 20:4 omega-6), the substrate for a wide array of reactive oxygenated metabolites. Because LA accounts for 85% to 90% of the dietary omega-6 PUFA, this advisory focuses primarily on this fatty acid, recognizing that dietary AA, which can affect tissue AA levels,5 may have physiological sequelae.6–8 LA comes primarily from vegetable oils (eg, corn, sunflower, safflower, soy). The average US intake of LA, according to National Health and Nutrition Examination Survey 2001 to 2002 data for adults ≥19 years of age, is 14.8 g/d.9 On the basis of an average intake of 2000 kcal/d, LA intake is 6.7% of energy. AA (≈0.15 g/d) is consumed preformed in meat, …
TL;DR: An increased chest compression fraction is independently predictive of better survival in patients who experience a prehospital ventricular fibrillation/tachycardia cardiac arrest.
Abstract: Background— Quality cardiopulmonary resuscitation contributes to cardiac arrest survival. The proportion of time in which chest compressions are performed in each minute of cardiopulmonary resuscit...
TL;DR: An overview of the current state of knowledge and future perspectives with regard to optimal prosthesis selection and clinical management after valve implantation is provided.
Abstract: The introduction of valve replacement surgery in the early 1960s has dramatically improved the outcome of patients with valvular heart disease. Approximately 90 000 valve substitutes are now implanted in the United States and 280 000 worldwide each year; approximately half are mechanical valves and half are bioprosthetic valves. Despite the marked improvements in prosthetic valve design and surgical procedures over the past decades, valve replacement does not provide a definitive cure to the patient. Instead, native valve disease is traded for “prosthetic valve disease,” and the outcome of patients undergoing valve replacement is affected by prosthetic valve hemodynamics, durability, and thrombogenicity. Nonetheless, many of the prosthesis-related complications can be prevented or their impact minimized through optimal prosthesis selection in the individual patient and careful medical management and follow-up after implantation. The purpose of this article is to provide an overview of the current state of knowledge and future perspectives with regard to optimal prosthesis selection and clinical management after valve implantation.
The ideal valve substitute should mimic the characteristics of a normal native valve. In particular, it should have excellent hemodynamics, long durability, high thromboresistance, and excellent implantability. Unfortunately, this ideal valve substitute does not exist, and each of the currently available prosthetic valves has inherent limitations.
### Mechanical Valves
Three basic types of mechanical valve design exist: bileaflet, monoleaflet, and caged ball valves (Figure 1A, 1B, and 1C).
Figure 1. Different types of prosthetic valves. A, Bileaflet mechanical valve (St Jude); B, monoleaflet mechanical valve (Medtronic Hall); C, caged ball valve (Starr-Edwards); D, stented porcine bioprosthesis (Medtronic Mosaic); E, stented pericardial bioprosthesis (Carpentier-Edwards Magna); F, stentless porcine bioprosthesis (Medtronic Freestyle); G, percutaneous bioprosthesis expanded over a balloon (Edwards Sapien); H, self-expandable percutaneous bioprosthesis (CoreValve).
#### Caged Ball Valves
Caged ball valves, which consist of a silastic ball with a circular sewing ring and a …
TL;DR: Relatively low levels of fine particulate exposure from either air pollution or secondhand cigarette smoke are sufficient to induce adverse biological responses increasing the risk of cardiovascular disease mortality.
Abstract: Background— Fine particulate matter exposure from both ambient air pollution and secondhand cigarette smoke has been associated with larger risks of cardiovascular mortality than would be expected on the basis of linear extrapolations of the relative risks from active smoking. This study directly assessed the shape of the exposure-response relationship between cardiovascular mortality and fine particulates from cigarette smoke and ambient air pollution. Methods and Results— Prospective cohort data for >1 million adults were collected by the American Cancer Society as part of the Cancer Prevention Study II in 1982. Cox proportional hazards regression models that included variables for increments of cigarette smoking and variables to control for education, marital status, body mass, alcohol consumption, occupational exposures, and diet were used to describe the mortality experience of the cohort. Adjusted relative risks of mortality were plotted against estimated average daily dose of fine particulate matte...
TL;DR: This review focuses on recent findings and interaction between endothelium-dependent vasodilation and oxidative stress in cardiovascular diseases.
Abstract: The vascular endothelium is involved in the release of various vasodilators, including nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factor, as well as vasoconstrictors. NO plays an important role in the regulation of vascular tone, inhibition of platelet aggregation, and suppression of smooth muscle cell proliferation. Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis. Cardiovascular diseases are associated with endothelial dysfunction. It is well known that the grade of endothelial function is a predictor of cardiovascular outcomes. Oxidative stress plays an important role in the pathogenesis and development of cardiovascular diseases. Several mechanisms contribute to impairment of endothelial function. An imbalance of reduced production of NO or increased production of reactive oxygen species, mainly superoxide, may promote endothelial dysfunction. One mechanism by which endothelium-dependent vasodilation is impaired is an increase in oxidative stress that inactivates NO. This review focuses on recent findings and interaction between endothelial function and oxidative stress in cardiovascular diseases. (Circ J 2009; 73: 411 - 418)
TL;DR: In the first randomized study on elective stent-graft placement in survivors of uncomplicated type B aortic dissection, TEVAR failed to improve 2-year survival and adverse event rates despite favorable aorti remodeling.
Abstract: Background— Thoracic endovascular aortic repair (TEVAR) represents a novel concept for type B aortic dissection. Although life-saving in acute emergencies, outcomes and survival of TEVAR in stable dissection are unknown. Methods and Results— One hundred forty patients in stable clinical condition at least 2 weeks after index dissection were randomly subjected to elective stent-graft placement in addition to optimal medical therapy (n=72) or to optimal medical therapy alone (n=68) with surveillance (arterial pressure according to World Health Organization guidelines ≤120/80 mm Hg). The primary end point was all-cause death at 2 years, whereas aorta-related death, progression (with need for conversion or additional endovascular or open surgery), and aortic remodeling were secondary end points. There was no difference in all-cause deaths, with a 2-year cumulative survival rate of 95.6±2.5% with optimal medical therapy versus 88.9±3.7% with TEVAR (P=0.15); the trial, however, turned out to be underpowered. Mo...
TL;DR: Myocardial fibrosis is an important morphological substrate of postoperative clinical outcome in patients with severe aortic stenosis and was not reversible after AVR over the 9 months of follow-up examined in this study.
Abstract: Background In this prospective follow-up study, the effect of myocardial fibrosis on myocardial performance in symptomatic severe aortic stenosis was investigated, and the impact of fibrosis on clinical outcome after aortic valve replacement (AVR) was estimated. Methods and results Fifty-eight consecutive patients with isolated symptomatic severe aortic stenosis underwent extensive baseline characterization before AVR. Standard and tissue Doppler echocardiography and cardiac magnetic resonance imaging (late-enhancement imaging for replacement fibrosis) were performed at baseline and 9 months after AVR. Endomyocardial biopsies were obtained intraoperatively to determine the degree of myocardial fibrosis. Patients were analyzed according to the severity of interstitial fibrosis in cardiac biopsies (severe, n=21; mild, n=15; none, n=22). The extent of histologically determined cardiac fibrosis at baseline correlated closely with New York Heart Association functional class and markers of longitudinal systolic function (all P Conclusions Myocardial fibrosis is an important morphological substrate of postoperative clinical outcome in patients with severe aortic stenosis and was not reversible after AVR over the 9 months of follow-up examined in this study. Because markers of longitudinal systolic function appear to indicate sensitively both the severity of myocardial fibrosis and the clinical outcome, they may prove valuable for preoperative risk assessment in patients with aortic stenosis.