Coronary artery atherosclerosis: Severity of the disease, severity of angina pectoris and compromised left ventricular function

Abstract

To determine if the severity of angina pectoris and the degree of altered left ventricular function correlated with the severity and extent of the underlying coronary artery disease, a coronary scoring system was derived. The system was based on the severity of luminal diameter narrowing and weighted according to the usual flow to the left ventricle in each coronary vessel. Thus, the most weight was given to the left main coronary artery, followed by the left anterior descending, circumflex, and right coronary arteries. The resultant number was an indicator of the overall severity of the obstructive coronary artery disease. A coronary arterial system with no obstructive disease was scored as zero and the greater the degree of obstructive disease present, the higher the coronary score. From 202 subjects, four groups were evaluated: group 1 - coronary score = 0.5-4.5 (n = 10); group 2 - coronary score = 10.5-12.5 (n = 11); group 3 - coronary score = 17.5-20.5 (n = 11); and group 4 - coronary score = 25.0-36.0 (n = 11). All subjects had coronary artery bypass surgery and had preoperative and 1-year postoperative cardiac catheterization, including atrial pacing to maximal heart rate. The groups could not be separated on the basis of angina frequency, resting heart rate, cardiac index, left ventricular end-diastolic pressure, peak paced left ventricular end-diastolic pressure, dP/dt, V max, left ventricular end-diastolic volume index, left ventricular end-systolic volume index, stroke volume index, ejection fraction or mean circumferential fiber shortening velocity. Thus, based on this study, the severity of coronary disease does not statistically correlate with the frequency of angina pectoris or produce a predictable degree of altered left ventricular function. The frequency of angina pectoris cannot be used to predict prognosis or the adequacy of myocardial revascularization.