Impact of coronary artery spasm on 10-year clinical outcomes in mild-to-moderate atherosclerosis

Background Epicardial atherosclerosis burden was frequently coexisted with coronary artery spasm (CAS). However, prognostic data regarding patients with CAS, particularly those with insignificant stenosis, remain limited. Methods A total of 4,218 patients with insignificant coronary stenosis (30–69% diameter stenosis) who underwent acetylcholine (ACH) or ergonovine (ERG) provocation tests between January 2004 and October 2024 were enrolled. Significant CAS was defined as transient > 70% luminal narrowing with or without ischemic ST-T segment changes or chest pain. The study population was divided into a CAS group and a control group. We compared 10-year major clinical outcomes between the two groups using propensity score matching (PSM) to adjust for baseline confounders. Results After PSM, 1,197 matched pairs were generated, with well-balanced baseline characteristics between the CAS and control groups. In the Cox proportional hazards regression analysis, the CAS group had a significantly lower incidence of all-cause mortality (HR: 0.48, 95% CI: 0.24–0.96) and major adverse cardiac and cerebrovascular events (MACCE; HR: 0.71, 95% CI: 0.53–0.97) up to 10 years. In a landmark analysis beyond 5 years, however, the CAS group showed a significantly higher incidence of recurrent chest pain (HR: 1.49, 95% CI: 1.04–2.13). (Table). Conclusions In patients with insignificant coronary stenosis, the presence of CAS was associated with lower risks of long-term mortality and MACCE, probably due to intensive optimal medical therapy. However, these patients had a higher risk of recurrent chest pain beyond 5 years. Further studies are needed to confirm these findings.CAS_insig_fixed-Rha