Prognostic significance of provocative spasm tests in patients with myocardial infarction with and without obstructive coronary arteries

BACKGROUND AND AIMS: Coronary spasm may contribute to the pathogenesis of myocardial infarction with obstructive coronary artery disease (MICAD) and warrants close consideration in myocardial infarction with non-obstructive coronary arteries (MINOCA). However, data concerning the significance of coronary spasm in acute myocardial infarction (AMI) are limited. We assessed the prognostic significance of provocative spasm tests among MICAD and MINOCA patients. METHODS AND RESULTS: We retrospectively screened 731 consecutive patients with AMI, of whom 267 (MICAD, n = 198; MINOCA, n = 69) underwent an invasive provocative spasm test. The primary endpoint was major adverse cardiac events (MACE). Provocative spasm testing was positive in 143 (72.2%) of MICAD group and 33 (47.8%) of MINOCA group. During a median follow-up of 48 months, MACE occurred in 31 patients (15.7%) in the MICAD group compared with 4 patients (5.8%) in the MINOCA group (p = 0.037). Spasm-positive patients had a significantly higher incidence of MACE compared with spasm-negative patients in both the MICAD group (27 [18.9%] vs. 4 [7.3%]; p = 0.044) and MINOCA group (4 [12.1%] vs. 0 [0%]; p = 0.047). Kaplan-Meier survival analysis of the 4 groups categorized by type of AMI (MICAD or MINOCA) and presence of provoked coronary spasm showed that spasm-positive status was associated with lower MACE-free survival across both AMI subtypes (log-rank p = 0.011). In multivariable analysis, provoked coronary spasm was independently associated with MACE in the MICAD group (hazard ratio, 3.40; 95% confidence interval, 1.20-12.25; p = 0.019). CONCLUSION: Provocative spasm tests could provide prognostic stratification for AMI patients, irrespective of whether they present with MICAD or MINOCA.