Acetylcholine-Provoked Coronary Spasm at Site of Significant Organic Stenosis Predicts Poor Prognosis in Patients With Coronary Vasospastic Angina

BackgroundCoronary artery spasm contributes to the pathogenesis of variant angina and ischemic heart disease and may play a role in the progression of atherosclerosis. It is unclear whether the location of spasm is related to outcome.ObjectivesThis study compared the clinical features and prognosis of patients with coronary spasm at the site of significant atherosclerotic stenosis with patients with spasm at sites without stenosis or nonsignificant stenosis.MethodsThis was a retrospective, observational study of 1,877 consecutive patients with typical or atypical angina-like chest pain undergoing acetylcholine (ACh)-provocation testing. A total of 1,760 patients were eligible for analysis. ACh-provoked coronary spasm and significant organic stenosis were observed in 873 and 358 patients, respectively.ResultsIn patients with significant atherosclerotic stenosis, ACh-positive patients (n = 233) were younger and without diabetes mellitus compared with nonspasm patients (n = 125). In patients without organic stenosis, ACh-positive patients (n = 640) were older, had dyslipidemia, and were more likely to have a family history of ischemic heart disease than nonspasm patients (n = 762). Multiple logistic regression analysis identified ST-segment elevation during anginal attacks, organic stenosis of the left anterior descending artery, and multivessel spasm as correlates of spasm at sites of significant organic stenosis (n = 192). Multivariate analysis identified ACh-provoked spasm at the site of significant stenosis and use of nitrates as the 2 prognostic factors for major adverse cardiac events.ConclusionsThe clinical features and prognosis of patients with ACh-provoked coronary spasm were different when it occurred at the site of significant atherosclerotic stenosis compared with patients with spasm elsewhere. Both spasm at the site of significant organic stenosis and nitrate use were significant predictors of major adverse cardiac events.