Adverse cardiovascular events arising from atherosclerotic lesions with and without angiographic disease progression.

OBJECTIVES The aim of this study was to use angiography and grayscale and intravascular ultrasound-virtual histology to assess coronary lesions that caused events during a median follow-up period of 3.4 years. BACKGROUND Vulnerable plaque-related events are assumed to be the result of substantial progression of insignificant lesions. METHODS In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, 697 patients with acute coronary syndromes underwent treatment of all culprit lesions followed by 3-vessel imaging to assess the natural history of culprit and untreated nonculprit (NC) lesions. Future adverse cardiovascular events adjudicated to NC lesions were divided into those with versus without substantial lesion progression (SLP) (≥ 20% angiographic diameter stenosis increase). RESULTS NC lesion events occurred in 72 patients, 44 (61%) with and 28 (39%) without SLP. Myocardial infarctions (n = 6) occurred only in patients with SLP. Conversely, patients without SLP presented only with unstable or increasing angina requiring rehospitalization. Lesions with versus without SLP occurred later (median time to event 401 vs. 223 days, p = 0.07); were less severe at baseline (median diameter stenosis 26.4% vs. 53.8%, p < 0.0001) but more severe at the time of the event (mean diameter stenosis 73.8% vs. 56%, p < 0.0001); and had comparable baseline median plaque burden (68.7% vs. 70.1%, p = 0.17), minimum luminal area (3.7 vs. 4.0 mm(2), p = 0.60), and intravascular ultrasound-virtual histology phenotype (83.3% vs. 90.9%, p = 0.68; classified as fibroatheromas at baseline). CONCLUSIONS NC lesions responsible for future cardiovascular events showed angiographic increase during 3.4 years of follow-up, whereas SLP underlay many but not all of them. NC events due to lesions with SLP were angiographically less severe and presented with a delayed time course but were otherwise indistinguishable from NC events that were not associated with SLP.