The natural course of nonculprit coronary artery lesions; analysis by serial quantitative coronary angiography

Abstract

Background Nonculprit lesions are the major cause of future cardiovascular events. However, the natural course of nonculprit lesions and angiographic predictors of plaque progression are not well-studied. The purpose of our study was to observe the natural course of nonculprit lesions, and to identify predictors of unanticipated future events and angiographic progression in nonculprit lesions.

Methods We analyzed 640 nonculprit lesions with a length of ≥2mm and luminal narrowing ≥30% from 320 patients who had two serial angiographic follow-ups; 9 to 13months post-PCI and 24months post-PCI. The study endpoints were nonculprit-ischemia driven revascularization (IDR) and the rate of diameter stenosis (DS) progression. Those with progression of DS > 12%/year were defined as rapid progressors.

Results During the median follow-up period of 737days, 20 lesions in 20 patients (6.3%) required nonculprit-IDR. Independent predictors of nonculprit-IDR were diabetes (hazard ratio [HR] 2.93, 95% confidence interval [CI] 1.072–8.007, p = 0.036) and lesion type B2/C (HR 4.017, 95% CI 1.614–9.997, p = 0.003). The presence of one or both of the two major risk factors was associated with significant DS progression (3.0 ± 6.8% vs. 3.5 ± 6.1% vs. 6.8 ± 9.9% for lesions with 0, 1 and both risk factors, p < 0.001). Among the 640 lesions, 38 lesions (5.9%) in 33 patients were rapid progressors, while risk factors of rapid progressors included lesion type B2/C as a lesion-related risk factor (HR 1.998, 95% CI 1.006–3.791, p = 0.048) and diabetes mellitus as a patient-related risk factor (HR 3.725, 95% CI 1.937–7.538, p < 0.001). Lesions with both risk factors (type B2/C lesions in diabetic patients) were at the highest risk of rapid progression (odds ratio 3.250, 95% CI 1.451–7.282), compared to type A/B1 lesions in non-diabetic patients.

Conclusion Nonculprit-IDR was not uncommon during the 2-year follow up period in our population. The major risk factors of nonculprit lesion progression were diabetes and lesion type B2/C.

Trial registration Retrospectively registered and approved by the institutional review board of Seoul National University Hospital (No.: 1801–138-918) on February 2nd, 2018.