Detection of the Vulnerable Coronary Atherosclerotic Plaque—Promises and Limitations

Abstract

The merit of imaging “vulnerable atherosclerotic plaques” remains highly controversial. This review aims at providing current evidence for both its benefit and limitations. Results from optical coherence tomography and intravascular ultrasound imaging in patients with coronary heart disease suggest that certain individual coronary atherosclerotic plaque characteristics, e.g., large lipid core in a fibroatheroma, are associated with greater risk of adverse patient outcome. However, a closer look at these studies reveals that these associations are confounded by the relationship of “vulnerable plaque” characteristics with baseline lumen obstruction, which is a known predictor of recurrent angina and the main component of the reported adverse patient outcome. Recent insights into the pathophysiology of acute coronary syndromes suggest it to be an exceedingly complex process involving numerous local and systemic factors, which hinders outcome prediction. The quest for the vulnerable plaque rests on the erroneous assumption that detecting coronary atherosclerotic lesions, which are prone to rupture or erode, will identify individuals at high risk of suffering acute coronary events. However, there is strong and consistent evidence suggesting that plaques most commonly rupture without associated clinical symptoms. Instead, ruptured plaques typically heal clinically silently and lead to plaque progression. The atherosclerotic disease burden, its metabolic activity, and risk factors for an inadequate response by the coagulation system to plaque disruption, on the other hand, are important predictors of acute coronary event risk and deserve our attention more than individual plaques.