Five-year major clinical outcomes according to severity of coronary artery spasm as assessed by intracoronary acetylcholine provocation test.

BACKGROUND: Long-term clinical outcome data according to severity of coronary artery spasm (CAS) as assessed by an intracoronary acetylcholine provocation test are limited in series of Asian patients.

AIM: To investigate 5-year clinical outcomes in patients with CAS according to CAS severity.

METHODS: In total, 5873 consecutive patients with insignificant coronary artery disease (<70% fixed stenosis) who underwent an acetylcholine provocation test were enrolled and divided into four groups according to CAS severity during the acetylcholine provocation test: negative, borderline positive, moderately positive and severely positive. CAS severity was assessed by quantitative coronary angiography. We investigated 5-year clinical outcomes according to CAS severity.

RESULTS: Over a follow-up period of up to 5 years, before adjustment, the severely-positive CAS group showed a significantly higher incidence of major adverse cardiac events (MACE; composite of death, myocardial infarction and de novo revascularization) (hazard ratio [HR]: 1.834, 95% confidence interval [CI]: 1.047-3.211; P=0.033), total death (HR: 3.124, 95% CI: 1.047-9.322; P=0.041), myocardial infarction (HR: 3.190, 95% CI: 1.069-9.519; P=0.037) and recurrent angina (HR: 1.762, 95% CI: 1.363-2.278; P<0.001) compared with the negative group. However, after adjustment for baseline confounders, only the incidence of recurrent angina (HR: 1.323, 95% CI: 1.014-1.726; P=0.039) was significantly higher in the severely-positive CAS group compared with the negative group.

CONCLUSIONS: The severity of CAS in the positive group was not associated with an increased incidence of MACE after adjustment for covariates compared with the negative group, but the severely-positive CAS group was associated with a higher incidence of recurrent angina compared with the negative group.