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 on late luminal narrowing and clinical events remains poorly understood. Methods and Results: This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention and serial optical coherence tomography at baseline and 1-year follow-up to investigate nontarget regions with angiographically intermediate stenosis. At 1 year after percutaneous coronary intervention, the coronary artery lumen area decreased significantly from 6.06 (95% CI, 5.60–6.53) mm2 to 5.88 (95% CI, 5.41–6.35) mm2 (difference, −0.18; 95% CI, −0.22 to −0.14 mm2; P<0.001), particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of fibroatheroma decreased from 38% to 36% (P<0.001), whereas calcified plaque increased from 31% to 34% (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. Patients with thin-cap fibroatheroma had a significantly higher 3-year risk of ischemia-driven nontarget vessel revascularization (hazard ratio, 2.42 [95% CI, 1.03–5.71]; P=0.04), primarily due to revascularization in the imaged region. No significant association was observed between coronary artery calcium prevalence and clinical outcomes within 3 years. Conclusions: The coronary artery lumen area significantly decreased over a 1-year interval, particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although thin-cap fibroatheroma prevalence was associated with higher risk of ischemia-driven nontarget vessel revascularization, 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. Registration: URL: https://www.umin.ac.jp/ctr/; Unique Identifier: UMIN000031937.