The Prognostic Significance of the Characteristics of Atherosclerotic Plaques Left after Percutaneous Coronary Intervention in the Development of Cardiovascular Events in Patients With Acute Coronary Syndrome According to Computed Tomographic Angiography of the Coronary Arteries

Abstract

Aim: To determine the characteristics of atherosclerotic plaques (ASP) remaining after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), that are significantly associated with cardiovascular events (CVE), according to computed tomography angiography (CTA) data.

Material and methods: CTA was performed in 249 ACS patients on days 3-7 of the disease (in 41 patients, on a 64-slice CT scanner, and in the rest, on a 320-slice CT scanner). CTA data of all patients were analyzed on a Vitrea workstation. Patients with at least one noncalcified atherosclerotic plaque were included.

Results: During 39.1 [18.0; 57.4] months of follow-up (from 7 days to 128 months), 71 of 249 (28.5%) ACS patients had the primary endpoint (PEP), which included non-fatal myocardial infarction, unstable angina, cardiac death, PCI, and ischemic stroke. According to the univariate Cox analysis, 14 of 30 CTA characteristics of ASP turned out to be significant predictors of achieving the PEP: the number of involved arteries (HR=1.314, CI: 1.06-1.628, p=0.013, C=0.59); the total length of ASPs (HR=1.013, CI: 1.005-1.022, p=0.002, C=0.62); the number of ASPs with obstructive stenosis (HR=1.286, CI: 1.095-1.509, p=0.002, C=0.61); the minimum density (HR=0.968, CI: 0.949-0.987, p=0.001, C=0.64); a minimum density <30 HU (HR=2.695, CI: 1.495-4.869, p=0.0009, C=0.62); the number of ASPs with a minimum density <30 HU (HR=1.391, CI: 1.186-1.633, p=0.00005, C=0.64); the number of ASPs with a minimum density ≤46 HU (HR=1.211, CI: 1.043-1.407, p=0.012, C=0.58); the presence of a low-density area <30 HU (HR=2.387, CI: 1.389-4.101, p=0.001, C=0.57); the number of atherosclerotic plaques with a low-density area <30 HU (OR=1.912, CI: 1.317-2.775, p=0.001, C=0.57); the number of atherosclerotic plaques with spotty calcifications (HR=1.384, CI: 1.134-1.688, p=0.001, C=0.59); the maximum length (HR=1.014, CI: 1.001-1.028, p=0.041, C=0.61); the maximum stenosis (HR=1.018, CI: 1.002-1.033, p=0.025, C=0.61); the presence of a low-density area ≤46 HU (HR=2.049, CI: 1.24-3.386, p=0.005, C=0.57); the number of ASPs with a low-density area ≤46 HU (HR=1.643, CI: 1.191-2.265, p=0.002, C=0.58). [HR, hazard ratio; CI, 95% confidence interval; C, Harrell's C statistics]. According to the multivariate analysis, the first 10 of the listed CTA characteristics retained their prognostic significance, while the predictive significance was found for the "total plaque burden", a conditional characteristic we first proposed, which is the sum of the areas (burden) of all plaques identified by CTA in the patient.

Conclusion: 14 CTA characteristics of ASPs in patients with ACS are significant predictors of future CVE, and 11 of them are independent of known risk factors.