Percutaneous Coronary Intervention for Vulnerable Coronary Atherosclerotic Plaque

BACKGROUND Acute coronary syndromes most commonly arise from thrombosis of lipid-rich coronary atheromas that have large plaque burden despite angiographically appearing mild. OBJECTIVES We sought to examine the outcomes of percutaneous coronary intervention (PCI) of non-flow-limiting vulnerable plaques. METHODS Three-vessel imaging was performed with a combination intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) catheter after successful PCI of all flow-limiting coronary lesions in 898 patients presenting with myocardial infarction (MI). Patients with an angiographically non-obstructive stenosis not intended for PCI but with IVUS plaque burden ≥65% were randomized to treatment of the lesion with a bioresorbable vascular scaffold (BVS) plus guideline-directed medical therapy (GDMT) vs. GDMT alone. The primary powered effectiveness endpoint was the IVUS-derived minimum lumen area (MLA) at protocol-driven 25-month follow-up. The primary (non-powered) safety endpoint was randomized target lesion failure (TLF; cardiac death, target vessel-related MI or clinically-driven target lesion revascularization) at 24 months. The secondary (non-powered) clinical effectiveness endpoint was randomized lesion-related major adverse cardiac events (MACE; cardiac death, MI, unstable angina, or progressive angina) at latest follow-up. RESULTS A total of 182 patients were randomized (93 BVS, 89 GDMT alone) at 15 centers. The median angiographic diameter stenosis of the randomized lesions was 41.6%; by NIRS-IVUS median plaque burden was 73.7%, median MLA was 2.9 mm2, and median maximum lipid plaque content was 33.4%. Angiographic follow-up at 25 months was completed in 167 patients (91.8%), and median clinical follow-up was 4.1 years. The follow-up MLA in BVS-treated lesions was 6.9±2.6 mm2 compared with 3.0±1.0 mm2 in GDMT alone-treated lesions (least square means difference 3.9 mm2, 95% CI 3.3-4.5, P<0.0001). TLF at 24 months occurred in similar rates of BVS-treated and GDMT alone-treated patients (4.3% vs. 4.5%; P=0.96). Randomized lesion-related MACE occurred in 4.3% BVS-treated patients vs. 10.7% GDMT alone-treated patients (OR 0.38, 95% CI 0.11-1.28, P=0.12). CONCLUSIONS PCI of angiographically mild lesions with large plaque burden was safe, substantially enlarged the follow-up MLA and was associated with favorable long-term clinical outcomes, warranting the performance of an adequately powered randomized trial.