Angiographic predictors of new coronary occlusions

To determine whether coronary angiography is predictive of the future site of coronary occlusion, we analyzed the coronary angiograms of 246 consecutive patients having two or more angiograms without therapeutic invasive intervention in the interval between angiograms. The average interval between studies was 46 months. Of 2183 normal segments at the first angiogram, 51 (2.3%) were occluded at the second angiogram, whereas in segments with minimal disease (1% to 25% diameter stenosis) 33 (8%) of 411 were occluded (p < 0.05). There was a further stepwise increase in the occlusion ratio, with increasing stenosis reaching a 31% occlusion ratio in lesions with critical (91% to 99%) stenosis at the first angiogram. For any given degree of stenosis, the occlusion ratio of "long" lesions (5 to 20 mm) was on the average more than twice that of "short" lesions (< 5 mm, p < 0.01), except in lesions with critical stenosis (91% to 99%) where length was no longer important. Occlusion of segments judged free of disease on the first angiogram was highest in the right coronary artery, 4.7%, versus 2.7% in the left anterior descending and 0.6% in the circumflex artery (p < 0.01). History of recent myocardial infarction was a good clinical predictor of occlusion and deterioration of ventricular function.