Coronary vasospasm and cardiovascular outcomes in patients with isolated myocardial bridging: A retrospective study.

Background: Mounting evidence suggests an associated between myocardial bridging (MB) and coronary vasospasm (CVS); however, no consensus has been established on whether CVS worsens clinical outcomes in patients with MB. Therefore, this retrospective study aimed to compare the long-term clinical outcomes in patients with MB based on CVS presence.

Methods: This retrospective study enrolled 254 consecutive patients with MB undergoing provocative testing for coronary reactivity between January 1, 2009 and December 30, 2015, and stratified them into 2 groups: (a) group A (with CVS, n = 168); and (b) group B (without CVS, n = 86). The primary endpoints were major adverse cardiovascular events (MACEs), a composite of cardiac death, cardiac arrest, non-fatal myocardial infarction, ischemia-driven revascularization, ischemia-driven coronary angiography, and ischemia-related hospitalization. Diverse Cox models were used to determine whether CVS independently influenced MACE.

Results: The mean age of study participants was 50.8 years, and 60.2% of them were male. The median follow-up period was 8.15 years. The rate of MACE was 35.1% and 26.7% in groups A and B, respectively. Group A had a significantly higher risk of MACE than group B (the reference group) in model 3 (hazard ratio [HR]:1.92; 95% confidence interval [CI]:1.12-3.29) and model 4 (adjusted HR: 1.94; 95% CI: 1.04-3.59).

Conclusions: The presence of CVS adversely affects clinical outcomes in patients with MB. Further prospective clinical studies are required to confirm this association.