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: This study 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 nonobstructive stenosis not intended for PCI but with IVUS plaque burden of ≥65% were randomized to treatment of the lesion with a bioresorbable vascular scaffold (BVS) plus guideline-directed medical therapy (GDMT) versus GDMT alone. The primary powered effectiveness endpoint was the IVUS-derived minimum lumen area (MLA) at protocol-driven 25-month follow-up. The primary (nonpowered) safety endpoint was randomized target lesion failure (cardiac death, target vessel–related MI, or clinically driven target lesion revascularization) at 24 months. The secondary (nonpowered) clinical effectiveness endpoint was randomized lesion–related major adverse cardiac events (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 near-infrared spectroscopy–IVUS, the median plaque burden was 73.7%, the median MLA was 2.9 mm2, and the median maximum lipid plaque content was 33.4%. Angiographic follow-up at 25 months was completed in 167 patients (91.8%), and the 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% confidence interval: 3.3 to 4.5; p < 0.0001). Target lesion failure 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 major adverse cardiac events occurred in 4.3% of BVS-treated patients versus 10.7% of GDMT alone–treated patients (odds ratio: 0.38; 95% confidence interval: 0.11 to 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. (PROSPECT ABSORB [Providing Regional Observations to Study Predictors of Events in the Coronary Tree II Combined with a Randomized, Controlled, Intervention Trial]; NCT02171065