Objectives: We sought to identify the angiographic predictors of a future infarction, to study their interaction with time to infarction, patient risk factors and medications, and to evaluate their clinical utility for risk stratification.
Background: Identification of coronary lesions at risk of acute occlusion remains challenging. Stenosis severity is poorly predictive but other stenosis descriptors might be better predictors.
Methods: Eighty-four patients with an acute myocardial infarction and a coronary angiogram performed within the preceding 36 months (baseline angiogram), and after infarction were selected. All coronary stenoses (from 10% to 95% lumen diameter reduction) at baseline angiogram were analyzed by computer-assisted quantification. Each of the 84 lesions responsible for the infarction (culprit) was compared with the nonculprit stenoses (controls) in the same patient.
Results: Culprit lesions were more symmetrical (symmetry index +15%; p < 0.001), had steeper outflow angles (maximal angle +4 degrees; p < 0.001), were more severe (percent stenosis +5%; p = 0.001) and longer (+ 1.5 mm, p = 0.01) than controls. The symmetry index and the outflow angles were the two independent predictors of infarction at three-year follow-up. Stenosis severity predicted only infarctions occurring within 1 year after angiography. In moderately severe stenoses (40% to 70% stenosis), stratification using the symmetry index and outflow angles accurately predicted lesions remaining free of occlusion and infarction at three-year follow-up.
Conclusions: Better characterization of stenosis geometry might help to understand the pathophysiologic mechanisms triggering coronary occlusion and to stratify patients for improved care.