Non-invasive assessment of coronary calcification (original) (raw)
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Journal of the American College of Cardiology, 1997
Objectives. We compared, on a site by site basis, the morphologic features of coronary calcifications determined by electron beam computed tomography (EBCT) and angiographically defined coronary atherosclerosis. Background. Quantification of coronary calcification using EBCT is clinically useful for the prediction of coronary stenosis. However, the relation between calcification and angiographic findings has not been evaluated by site. Methods. We studied 251 consecutive patients who underwent elective coronary angiography for suspected coronary artery disease by EBCT and analyzed findings by site. Coronary calcifications were classified according to their length and width versus the diameter of the coronary artery in which the calcification was observed as: none, spotty, long, wide and diffuse. Results. Coronary calcifications were found in 666 (27%) of 2,470 segments. The positive predictive value (PPV) of coronary calcification for significant stenosis (> ؊ 75% densitometric narrowing) and for all angiographically detectable atherosclerotic lesions in a segment was 0.36 and 0.80, respectively. The PPV for significant stenosis and all atherosclerotic lesions was 0.04 and 0.17 in none, 0.18 and 0.59 in spotty, 0.32 and 0.87 in long, 0.40 and 0.84 in wide and 0.56 and 0.96 in diffuse calcifications, respectively. The PPV for both significant stenosis and all lesions differed significantly (p ؍ 0.001) among the morphologic groups. Of the 105 eccentric significant stenoses, 54 (53%) were classified as long or diffuse calcifications. Of the 95 significant stenoses with multiple irregularities, 61 (64%) showed diffuse calcification. Conclusions. Morphologic evaluation of coronary calcifications using EBCT improved the prediction of coronary stenosis on a site by site basis and provided information related to angiographic morphology.
Revista española de cardiología, 2007
Measurement of coronary artery calcification (CAC) is used in the evaluation of cardiovascular risk. We investigated its usefulness by comparing CAC assessment with that of various risk charts. We determined cardiovascular risk in patients without known atherosclerosis using the 1998 European Task Force (ETF), REGICOR (Registre Gironí del Corazón) and SCORE (Systematic Coronary Risk Evaluation) charts. CAC was assessed by computerized tomography and measurements were classified as low risk (i.e., score <1), intermediate risk (i.e., score 1-100), or high risk (i.e., score >100). The study included 331 patients (mean age 54 [8.5] years, 89% male). In 44.1%, CAC was detected (mean score 96 [278]). The degree of agreement between the cardiovascular risk derived from the CAC score and that derived from the SCORE and ETF charts was acceptable: kappa=.33 (P<.05) and kappa=.28 (P<.05), respectively, but agreement was poor with the REGICOR chart: kappa=.02 (P=.32). The SCORE and ...
Circulation, 2001
Background Electron-beam CT (EBCT) quantification of coronary artery calcification (CAC) allows noninvasive assessment of coronary atherosclerosis. We undertook a follow-up study to determine whether CAC extent, measured at the time of angiography by EBCT, predicted future hard cardiac events, comprising cardiac death and nonfatal myocardial infarction (MI). We also assessed the potential of selected coronary artery disease (CAD) risk factors, prior CAD event history (MI or revascularization), and angiographic findings (number of diseased vessels and overall disease burden) to predict subsequent hard events. Methods and Results Two hundred eighty-eight patients who underwent contemporaneous coronary angiography and EBCT scanning were contacted after a mean of 6.9 years. Vital status and history of MI during follow-up were determined. Cox proportional hazards models were used to compare the predictive ability of CAC extent with selected CAD risk factors, CAD event history, and angiog...
Journal of Epidemiology, 2012
Both American and European guidelines recommend coronary artery calcification (CAC) as a tool for screening asymptomatic individuals at intermediate risk. These recommendations are based on epidemiological studies mostly in the United States (U.S.). We review (1) the use of CAC in primary prevention of coronary heart disease (CHD) in the U.S., (2) epidemiological studies of CAC in asymptomatic adults outside of the U.S., and (3) international epidemiological studies of CAC. This review does not consider clinical studies of CAC among patients or symptomatic individuals. Studies in the U.S. have documented that CAC is a strong independent predictor of CHD for both sexes, middle-to old-age groups, various ethnic groups, and diabetics and nondiabetics and that CAC plays an important role in reclassifying individuals at intermediate into high risk. Studies in Europe support these conclusions. The Electron-Beam Tomography, Risk factor Assessment among Japanese and U.S. men in the post-World-War-II birth cohort (ERA JUMP) Study is the first international research comparing subclinical atherosclerosis including CAC in Japanese, Japanese Americans, Koreas, and Caucasians. The study has demonstrated that Japanese had lower levels of atherosclerosis compared to Caucasians whereas Japanese Americans compared to Caucasians had similar or higher levels. CAC is being established as a screening tool for asymptomatic individuals in Europe and the U.S. CAC is a powerful research tool, enabling us to describe the difference in atherosclerotic burden across populations. Such research could elucidate factors responsible for the population difference, which may lead to prevention of CHD.
Background-Electron-beam CT (EBCT) quantification of coronary artery calcification (CAC) allows noninvasive assessment of coronary atherosclerosis. We undertook a follow-up study to determine whether CAC extent, measured at the time of angiography by EBCT, predicted future hard cardiac events, comprising cardiac death and nonfatal myocardial infarction (MI). We also assessed the potential of selected coronary artery disease (CAD) risk factors, prior CAD event history (MI or revascularization), and angiographic findings (number of diseased vessels and overall disease burden) to predict subsequent hard events. Methods and Results-Two hundred eighty-eight patients who underwent contemporaneous coronary angiography and EBCT scanning were contacted after a mean of 6.9 years. Vital status and history of MI during follow-up were determined. Cox proportional hazards models were used to compare the predictive ability of CAC extent with selected CAD risk factors, CAD event history, and angiographic findings. Median CAC score was 160 (range 0 to 7633). The 22 patients who experienced hard events during follow-up were older and had more extensive CAC and angiographic disease (PϽ0.05). Only 1 of 87 patients with CAC score Ͻ20 experienced a subsequent hard event during follow-up. Event-free survival was significantly higher for patients with CAC scores Ͻ100 than for those with scores Ն100 (relative risk 3.20; 95% CI 1.17 to 8.71). When a stepwise multivariable model was used, only age and CAC extent predicted hard events (risk ratios 1.72 and 1.88, respectively; PϽ0.05).
American Heart Journal, 1996
The purpose of this investigation was to determine the variability of electron-beam computed tomography (EBCT) measurement of coronary calcification by using two commonly employed image-acquisition protocols and to compare this variability with that of a new image-acquisition protocol. We performed three EBCT scans within 15 minutes on each of 324 consecutive high-risk, asymptomatic subjects participating in an ongoing epidemiologic research investigation. Subjects were divided into three groups: group 1 (n = 175) received two scans with a standard 20-slice, 3 mm slice thickness image-acquisition protocol and a third scan with the new 20-slice, 6 mm slice thickness protocol; group 2 (n = 77) received two scans with a new 6 mm slice thickness image-acquisition protocol and a third scan with a standard 20-slice, 3 mm slice thickness protocol; group 3 (n = 72) received two scans with a 30-slice, 3 mm slice thickness image-acquisition protocol and a third scan with a 20-slice, 6 mm slice thickness protocol. Calcium score, calcium mass estimate, and calcium volume estimate were determined for each scan. We compared retest variability of calcium measurements for each of the three image-acquisition protocols. The variability of the new 6 mm slice thickness protocol was significantly lower than that of either the 20-slice 3 mm slice thickness protocol (p = 0.009) or the 30-slice 3 mm slice thickness protocol (p---0.02) for measurement of calcium score, mass, or volume. Retest reproducibility for all three image-acquisition protocolswas low; however, the 20-slice 6 mm slice thickness protocol gave reproducibility superior to either of the 3 mm slice thickness protocols. Variability of absolute indices increased, and variability of relative indices decreased as the value of these indices increased. EBCT is not sufficiently reproducible to allow serial quantitation of From St. John's Cardiovascular Research Center.
Stroke, 2002
Background and Purpose-Coronary calcification as detected by electron-beam CT measures the atherosclerotic plaque burden and has been reported to predict coronary events. Because atherosclerosis is a generalized process, coronary calcification may also be associated with manifest atherosclerotic disease at other sites of the vascular tree. We examined whether coronary calcification as detected by electron-beam CT is related to the presence of stroke. Methods-From 1997 onward, subjects were invited to participate in the prospective Rotterdam Coronary Calcification Study and undergo electron-beam CT to detect coronary calcification. The study was embedded in the population-based Rotterdam Study. Calcifications were quantified in a calcium score according to Agatston's method. Calcium scores were available for 2013 subjects (mean age [SD], 71 [5.7] years). Fifty subjects had experienced stroke before scanning. Results-Subjects were 2 times more likely to have experienced stroke when their calcium score was between 101 and 500 (odds ratio [OR], 2.1; 95% CI, 0.9 to 4.7) and 3 times more likely when their calcium score was above 500 (OR, 3.3; 95% CI, 1.5 to 7.2), compared with subjects in the lowest calcium score category (0 to 100). Additional adjustment for cardiovascular risk factors did not materially alter the risk estimates. Conclusions-In this population-based study, a markedly graded association was found between coronary calcification and stroke. The results suggest that coronary calcification as detected by electron-beam CT may be useful to identify subjects at high risk of stroke. (Stroke. 2002;33:462-465.)