Showing papers by "Stefan Martinoff published in 2010"
TL;DR: A coronary CTA protocol using 100 kVp tube voltage maintained image quality, but reduced radiation exposure by 31% as compared with the standard 120 kVP protocol, which should be considered for nonobese patients to keep radiation exposure as low as reasonably achievable.
Abstract: Objectives The purpose of this study was to evaluate image quality and radiation dose using a 100 kVp tube voltage scan protocol compared with standard 120 kVp for coronary computed tomography angiography (CTA). Background Concerns have been raised about radiation exposure during coronary CTA. The use of a 100 kVp tube voltage scan protocol effectively lowers coronary CTA radiation dose compared with standard 120 kVp, but it is unknown whether image quality is maintained. Methods We enrolled 400 nonobese patients who underwent coronary CTA: 202 patients were randomly assigned to a 100 kVp protocol and 198 patients to a 120 kVp protocol. The primary end point was to demonstrate noninferiority in image quality with the 100 kVp protocol, which was assessed by a 4-point grading score (1 = nondiagnostic, 4 = excellent image quality). For the noninferiority analysis, a margin of −0.2 image quality score points for the difference between both scan protocols was pre-defined. Secondary end points included radiation dose and need for additional diagnostic tests during follow-up. Results The mean image quality scores in patients scanned with 100 kVp and 120 kVp were 3.30 ± 0.67 and 3.28 ± 0.68, respectively (p = 0.742); image quality of the 100 kVp protocol was not inferior, as demonstrated by the 97.5% confidence interval of the difference, which did not cross the pre-defined noninferiority margin of −0.2. The 100 kVp protocol was associated with a 31% relative reduction in radiation exposure (dose-length product: 868 ± 317 mGy × cm with 120 kVp vs. 599 ± 255 mGy × cm with 100 kVp; p Conclusions A coronary CTA protocol using 100 kVp tube voltage maintained image quality, but reduced radiation exposure by 31% as compared with the standard 120 kVp protocol. Thus, 100 kVp scan protocols should be considered for nonobese patients to keep radiation exposure as low as reasonably achievable. (Prospective Randomized Trial on Radiation Dose Estimates of Cardiac CT Angiography in Patients Scanned With a 100 kVp Protocol [PROTECTION II]; NCT00611780)
233 citations
TL;DR: The results of the PROTECTION I Study suggest that the prospective ECG-triggered sequential coronary CTA technique significantly reduces radiation dose without impairing image quality when compared with the standard retrospective helical data acquisition in patients with a low and stable heart rate.
Abstract: OBJECTIVE. Concerns have been raised about the radiation exposure of coronary CT angiography (CTA). Recently, a prospective ECG-triggered sequential coronary CTA technique was developed to reduce exposure to ionizing radiation. The purpose of this analysis was to determine the impact of a sequential scanning technique on image quality and radiation dose in a prespecified subgroup analysis of the Prospective Multicenter Study on Radiation Dose Estimates of Cardiac CT Angiography I (PROTECTION I) Study when compared with a standard helical scanning technique.MATERIALS AND METHODS. This analysis comprises 685 64-MDCT coronary angiography studies of 47 international study sites in which the image quality was assessed by an experienced coronary CTA investigator using a 4-point score (1 = nondiagnostic, 4 = excellent image quality). Image quality was analyzed in all patients studied with the sequential scanning mode (n = 99) and in randomly selected patients of the population studied with the helical acquisitio...
87 citations
TL;DR: In this paper, the authors assessed the ability of coronary CT angiography (CCTA) to detect coronary artery disease in diabetic patients and to predict subsequent cardiac events and found that the best predictor of coronary heart disease was the atherosclerotic burden score, which measures the number of segments having either a nonstenotic plaque or stenosis.
Abstract: Objective: Diabetic patients have a high prevalence of coronary artery disease (CAD), but timely diagnosis of CAD remains challenging. We assessed the ability of coronary CT angiography (CCTA) to detect CAD in diabetic patients and to predict subsequent cardiac events. Methods: We analyzed 140 diabetic patients without known CAD undergoing CCTA. 1782 patients without diabetes were used as control group. Besides calcium scoring and the degree of the most severe stenosis, the atherosclerotic burden score counting the number of segments having either a nonstenotic plaque or a stenosis was recorded. The primary endpoint was a composite of hard cardiac events defined as all cause death, nonfatal myocardial infarction or unstable angina requiring hospitalization. Results: During a mean follow-up of 33 months, there were 7 events in the diabetes group and 24 events in the control group. The best predictor in diabetic patients was the atherosclerotic burden score: the annual event rate ranged from 0.5% for patients with less than 5 lesions to 9.6% for patients with more than 9 lesions resulting in a hazard ratio of 1.3 (95% CI 1.1 to 1.7) for each additional lesion (p=0.005). For comparison, in nondiabetic patients the annual event rate ranged from 0.3% to 2.2% respectively resulting in a hazard ratio of 1.2 (95%CI 1.1 to 1.3, p Conclusions: In diabetic patients without known CAD, CCTA can identify a patient group at particularly high risk for subsequent hard cardiac events.
67 citations
Journal Article•
TL;DR: In diabetic patients without known CAD, CCTA can identify a patient group at particularly high risk for subsequent hard cardiac events, and improved the prognostic value of conventional risk factors significantly.
59 citations
TL;DR: Although the event rate was low in asymptomatic patients, CCTA could reliably predict further cardiac events and could reclassify 2/3 of patients regarding their cardiovascular risk.
Abstract: To assess the value of coronary computed tomographic angiography (CCTA) in the prediction of cardiac events in asymptomatic patients, 451 consecutive asymptomatic patients who underwent CCTA from December 2003 to November 2007 were retrospectively analyzed. The primary end point of the study was the occurrence of cardiac events, defined as cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and late revascularization (>90 days after CCTA) during a median follow-up period of 27.5 months. Secondary end points were the prevalence of nonobstructive coronary lesions and the number of patients reclassified regarding their cardiovascular risk. Two hundred twenty-nine patients (54%) had nonobstructive coronary lesions, and 107 patients (24%) obstructive coronary artery disease. During follow-up, there were 2 cases of unstable angina and 8 revascularizations for stable angina. Patients with obstructive coronary artery disease had a significantly higher event rate than those without obstructive CAD (risk ratio 13.9, 95% confidence interval 4.0 to 48.0). In 217 patients (48%), the clinically assessed cardiovascular risk could be reclassified by CCTA from intermediate or high to low risk. In conclusion, although the event rate was low in asymptomatic patients, CCTA could reliably predict further cardiac events and could reclassify 2/3 of patients regarding their cardiovascular risk.
44 citations
TL;DR: Although the event rate was low in asymptomatic patients, CCTA could reliably predict further cardiac events and could reclassify 2/3 of patients regarding their cardiovascular risk.
12 citations
Journal Article•
TL;DR: This data indicates that plaques with low attenuation in coronary computed tomographic angiography (CCTA) are likely to be indicative of vulnerable plaques and to be particularly prone to plaque rupt...
Abstract: Background: Coronary plaques with low attenuation in coronary computed tomographic angiography (CCTA) are supposed to be indicative of vulnerable plaques and to be particularly prone to plaque rupt...
1 citations