Categories Of Coronary Artery Disease Research Articles

Cardiogoniometric parameters for detection of coronary artery disease at rest as a function of stenosis localization and distribution

Cardiogoniometry (CGM), a spatiotemporal electrocardiologic 5-lead method with automated analysis, may be useful in primary healthcare for detecting coronary artery disease (CAD) at rest. Our aim was to systematically develop a stenosis-specific parameter set for global CAD detection. In 793 consecutively admitted patients with presumed non-acute CAD, CGM data were collected prior to elective coronary angiography and analyzed retrospectively. 658 patients fulfilled the inclusion criteria, 405 had CAD verified by coronary angiography; the 253 patients with normal coronary angiograms served as the non-CAD controls. Study patients--matched for age, BMI, and gender--were angiographically assigned to 8 stenosis-specific CAD categories or to the controls. One CGM parameter possessing significance (P < .05) and the best diagnostic accuracy was matched to one CAD category. The area under the ROC curve was .80 (global CAD versus controls). A set containing 8 stenosis-specific CGM parameters described variability of R vectors and R-T angles, spatial position and potential distribution of R/T vectors, and ST/T segment alterations. Our parameter set systematically combines CAD categories into an algorithm that detects CAD globally. Prospective validation in clinical studies is ongoing.

Reduced endothelial progenitor cells in European and South Asian men with atherosclerosis

Circulating endothelial progenitor cells (EPCs) play a role in the repair and regeneration of the endothelium and may represent a novel cardiovascular risk factor. South Asian subjects have an increased risk of cardiovascular disease which is not fully explained by known risk factors. This study examined associations of EPCs with atherosclerosis and possible ethnic differences in EPCs. A population sample of 58 European and South Asian adult men was enriched with the recruitment of an additional 59 European and South Asian men with known coronary disease. The coronary artery calcification score was measured by multi-slice computerized tomography (CT), carotid and femoral intima-media thickness (IMT), and femoral plaques were measured by ultrasound. The subjects were further subdivided into three categories of coronary artery disease on the basis of coronary artery calcification score and clinical history. Total EPCs and non-senescent EPCs (ns-EPCs) were quantified after 5 days cell culture and the number of late outgrowth colonies was measured over a 6-week test period. Circulating CD34+ haematopoietic precursor cells were measured by flow cytometry. Individuals with femoral plaques had reduced total and ns-EPCs. The number of ns-EPCs were reduced in individuals with the most coronary atheroma and were inversely related to the coronary calcification score and femoral IMT. These relationships persisted after multivariate adjustment for other risk factors. The numbers of late outgrowth colonies or circulating CD34+ cells were unrelated to the presence of atherosclerosis. There were no differences in the number of EPCs between European and South Asian subjects. The number of EPCs are reduced in subjects with atherosclerosis independent of other risk factors. Reduction in EPC numbers may be an independent risk factor for atherosclerosis but does not explain ethnic differences in cardiovascular risk.

Association of low serum concentration of bilirubin with increased risk of coronary artery disease

We examined serum bilirubin and various liver-function enzymes as possible risk factors for angiographically documented coronary artery disease (CAD). The studies involved a "training" set of 619 men for whom complete data on all risk factors considered were available, and a "test" set of 258 men for whom some risk factor data were not available. In both study groups, the liver enzymes were not related to CAD; however, In[total bilirubin] was inversely and statistically significantly related to the presence of CAD, both univariately and multivariately after adjustment for the established risk factors of age, total cholesterol, high-density lipoprotein cholesterol, smoking history, and systolic blood pressure. A 50% decrease in total bilirubin was associated with a 47% increase in the odds of being in a more severe CAD category. Our data suggest that serum bilirubin is an inverse and independent risk factor for CAD, with an association equivalent in degree to that of systolic blood pressure.

Guidelines for the interpretation of the exercise radionuclide ventriculogram for diagnosing coronary artery disease

In 622 patients with known coronary artery anatomy, heart rate (HR) · blood pressure (BP) product and left ventricular (LV) ejection fraction (EF) at maximal supine exercise measured by radionuclide ventriculography were used to estimate, by logistic regression analysis, the probabilities of absence of significant coronary artery disease (CAD), presence of significant CAD, presence of multivessel CAD and presence of 3-vessel CAD. Thus, for example, estimated probabilities of each of the aforementioned 4 categories of CAD are 0.39, 0.61, 0.32 and 0.12, respectively, for HR · BP product of 26,000 beats · mm Hg/min and LVEF of 0.6 at maximal exercise and 0.08, 0.92, 0.77 and 0.48, respectively, for HR · BP of 15,000 and LVEF of 0.4. The graphic presentations of these estimated probabilities form useful guidelines for interpreting the results of exercise radionuclide ventriculography. In addition, specific cutoff values at maximal exercise defined 2 groups: (HR · BP product ≥ 21,000 beats · mm Hg/min and LVEF ⩾ 0.55) with a high (70%) likelihood of absence of significant CAD or 1-vessel CAD and a low (7%) likelihood of 3-vessel CAD, and (HR · BP product < 21,000 and LVEF < 0.55) with a high (72%) likelihood of multivessel CAD and a low (8%) likelihood of absence of CAD.

Exercise thallium scans: Patterns of use and impact on management of patients with known or suspected coronary artery disease

Physicians' ordering patterns and subjective assessments of the management impact of 345 exercise thallium studies at a tertiary care hospital were evaluated. Exercise thallium tests were ordered to obtain functional information (60%), to detect myocardial ischemia (29%), for routine follow-up (6%) and for screening for coronary artery disease (CAD) (5%). Exercise thallium testing was ordered instead of exercise electrocardiography alone because of an interest in assessing the size of an ischemic or infarcted area (37%), a belief that the exercise electrocardiogram was likely to be nondiagnostic (35%) or that exercise thallium was a better test (23%). In 20% of cases physicians said that thallium imaging results were helpful or pivotal in major management decisions, such as those regarding catheterization or surgery. In most cases, no further tests were ordered and antianginal therapy or activity prescription was changed after exercise thallium testing. Exercise thallium images also helped to stratify patients into low and high probability of CAD categories better than exercise electrocardiographic results alone did. Our data suggest that physicians are using exercise thallium testing to obtain functional information more often than simply to detect CAD and that physicians consider the test to be of considerable value.

Cigarette Smoking and Arteriographically Demonstrable Coronary Artery Disease

Patients undergoing selective coronary arteriography were studied to determine whether the extend of their coronary artery disease (CAD) was related to cigarette consumption. Those without demonstrable lesions averaged 29.0 pack years. Patients with single vessel disease, 38.3 pack years, those with double vessel disease 44.9 pack years and those with triple vessel disease 67.5 pack years. Nonsmokers with significant CAD were ten years older than their smoking counterparts (p less than 0.01). Forty-seven percent of patients with no demonstrable disease were nonsmokers whereas only 18 percnet of those with CAD were nonsmokers (p less than 0.001). Sixty-nine percent of nonsmoking normotensive patients had no CAD whereas only 23 percent of nonsmoking hypertensive patients fell in the no CAD category (p=0.01-0.005). This study demonstrates a correlation between the number of cigarettes consumed and the severity of CAD as well as the accelerating effect of cigarette consumption on the development of CAD. It also suggests that symptomatic CAD in a normotensive nonsmoker is unusual.