Clinical outcome according to spasm type of single coronary artery provoked by intracoronary ergonovine tests in patients without significant organic stenosis

Background This study aimed to evaluate clinical implications of single vessel coronary spasm provoked by intracoronary ergonovine provocation test in Korean population. Method A total of 1248 patients who presented with single vessel coronary artery spasm induced by intracoronary ergonovine provocation test, excluding 1712 with negative spasms, multiple and mixed coronary artery spasms and missing data among 2960 patients in the VA-KOREA (Vasospastic Angina in Korea) registry, were classified into diffuse (n = 705) and focal (n = 543) groups. Results The 24-month incidences of a composite primary endpoints (cardiac death, new-onset arrhythmia, and acute coronary syndrome) were determined. Over a median follow-up of 30 months, the composite primary end point occurred more frequently in the focal type patients than in the diffuse type patients (primary endpoint: adjusted hazard ratio [aHR], 1.658; 95% confidence interval [CI] 1.272 to 2.162, P < 0.001). Especially, unstable angina in ACS components played a major role in this effect (hazard ratio [HR], 2.365; 95% confidence interval [CI] 1.100 to 5.087, P = 0.028). Conclusion Focal type of single vessel coronary artery spasm in vasospastic angina (VSA) patients is found to be associated with worse clinical outcomes. It is thought that the effect is stemmed from unstable angina among ACS rather than the other components of primary endpoint. Therefore, focal type of single vessel coronary artery spasm in patients with VSA should be more carefully assessed and managed with appropriate medication.