Cardiac risk in men with angiographically normal coronary arteries or minimal coronary arteriosclerosis

It is accepted that the assessment of the global cardiac risk for the occurrence of a coronary event is basically for preventive strategies. In a retrospective study, we have estimated the initial 10-year risk in 54 consecutive men (mean age 53.1 years) without clinically coronary artery disease (CAD) by using the PROCAM Score Scheme and the FRAMINGHAM Scoring System. All individuals underwent coronary angiography for diagnostic reasons. Inclusion criteria were angiographically normal coronary arteries or coronary vessels with minimal arteriosclerosis (luminal diameter reduction < 35%). The extent of initial coronary arteriosclerosis was estimated semiquantitatively by the number of wall changed vessel segments S (proximal, medial, distal) of the 3 large epicardial coronary arteries. Individuals were devided into 3 risk categories with a 10-year risk/PROCAM <5% (gr. i), 5-20% (gr. ii) and > 20% (gr. III). The mean 10-year risk/PROCAM and FRAMINGHAM of the entire group was 14.0 and 14.1%, respectively. The number of vessel segments with minimal arteriosclerosis averaged S=2.6. There was a significant linear relation between the number of arteriosclerotic segments, grouped by S=0, 1-2, 3-4, >4 and the mean corresponding 10-year risk/PROCAM (r = 0.97; p < 0.025). The mean 10-year risk/PROCAM and FRAMINGHAM in gr. I was 2.1 +/- 1.1 and 5.1 +/- 3.5%, in gr. II 11.1 +/- 4.4 and 14.5 +/- 7.1% and in gr. III 25.4 +/- 3.3 and 20.4 +/- 6.2%, respectively (gr. I vs 11 vs III: p < 0.005). In gr. I an average of S = 0.8 +/- 1.4 segments, in gr. II of S = 2.4 +/- 1.8 and in gr. III of S 4.1 +/- 1.8 vessel segments revealed initial coronary arteriosclerosis (gr. I vs II vs III: p < 0.0 1 < 0.0025, respectively). In 42 of the 54 men (78%) there were 10-year follow-up data regarding sudden cardiac death, fatal and non-fatal myocardial infarction available. Thirty-two men of the follow-up group (78%) showed no cardiac event (gr. A, mean age 53.3 +/- 8.3 years). In 10 men (23.8%, 95% CI 19.7-32.5%) a fatal or non-fatal event occurred (gr. B, mean age 55.6 +/- 7.5 years). At the beginning of the study, the 10-year risk/PROCAM and FRAMINGHAM in gr. A was 12.0 +/- 9.3 and 14.1 +/- 8.0%, respectively. In gr. B the estimated 10-year risk was 18.7 +/- 8.0% (gr. A vs B: p < 0.025) and 17.6 +/- 7.6%, respectively (gr. A vs B: p = ns). No cardiac event occurred in the low risk group < 5% (mean 2.4 +/- 1.2%). In 23.8% (95% CI 19.2-36.8%) of the group with mild or moderate risk (5-20%, mean 10.4 +/- 4.1%) and in 38.5% (95% CI 29.5-53.1%) of the high risk group (> 20%, mean 25.6 +/- 3.3%) a fatal or non-fatal event occurred. The total cardiac mortality was 7.1% (95% CI 6.6-15.1%). Our study indicates that men mean aged 53 years without clinical CAD and with a high 10-year risk (> 20%), judged by the PROCAM Score Scheme, have a high probability of subclinical coronary arteriosclerosis and for the occurrence of a cardiac event. Thus, a strict distinction between primary and secondary prevention does not seem to be justified any more.