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.