Serial optical coherence tomography assessment of coronary atherosclerosis and long-term clinical outcomes

Abstract Background The impact of high-risk coronary artery plaques identified using optical coherence tomography (OCT) on late luminal narrowing and clinical events remains poorly understood. Methods This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention (PCI) and serial OCT at baseline and 1-year follow-up to investigate non-target regions with angiographically intermediate stenosis. The primary outcome measure was luminal narrowing within the matched regions of interest in the non-target regions over a 1-year period. The secondary outcome measures included all-cause death, cardiac death, nonfatal myocardial infarction, and ischemia-driven coronary artery revascularization within 3 years. Results At 1 year after PCI, the coronary artery lumen area in non-target regions significantly decreased from 6.06 (95% confidence interval [CI], 5.60–6.53) to 5.88 (95% CI, 5.41–6.35) mm2, with a difference of -0.18 (95% CI, -0.22 to -0.14 mm2; P<0.001). This decrease was pronounced in thin-cap fibroatheromas (TCFAs), thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of TCFAs decreased from 3.4% to 3.3% (P<0.001), whereas that of thick-cap fibroatheromas also decreased from 35% to 33% (P<0.001). Patients with TCFA had a significantly higher risk of ischemia-driven non-target vessel revascularization (hazard ratio [HR], 2.42; 95% CI, 1.03–5.71; P=0.04), primarily due to revascularization in the imaged region. The higher prevalence of fibroatheroma was associated with a numerically increased risk of imaged region revascularization (HR per 10%, 1.38; 95% CI, 0.97–1.97; P=0.07). The prevalence of coronary artery calcium significantly increased from 31% at baseline to 34% at 1-year follow-up (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. No significant association was observed between the prevalence of coronary artery calcium and clinical outcomes within 3 years. Conclusions Coronary artery lumen area significantly decreased over a 1-year interval, particularly in TCFAs, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years, the interaction between calcium progression and long-term clinical events necessitates further investigation.