Myocardial bridging in adult patients with hypertrophic cardiomyopathy.

OBJECTIVES This investigation examined the risk of sudden cardiac death and other mortality in adult patients with hypertrophic cardiomyopathy (HCM) who have myocardial bridging diagnosed at coronary angiography. BACKGROUND Several reports have associated myocardial bridging with an adverse prognosis in pediatric HCM patients, but the prognosis of myocardial bridging in adult patients with HCM is unknown. METHODS The coronary angiograms of 425 patients with HCM (mean age 60 +/- 15 years [range 18 to 89 years]) at the Mayo Clinic were examined for the presence of myocardial bridging. Clinical follow-up was conducted to assess mortality. Survival of patients with bridging was compared with HCM patients who also underwent angiography but who did not have evidence of bridging. RESULTS A total of 64 patients (15%) had myocardial bridging. The mean follow-up for the entire study was 6.8 +/- 5.4 years. There was no difference in survival free of all-cause mortality (5-year estimate, bridging vs. no bridging, 91% vs. 85%; p = 0.42), all cardiac death (93% vs. 89%; p = 0.60), and sudden cardiac death (95% vs. 97%; p = 0.72). Univariate and multivariate proportional hazards models also did not identify the presence of bridging or specific characteristics of the degree or extent of bridging with a poor outcome. CONCLUSIONS This study observed no increased risk of death, including sudden cardiac death, among adult patients with HCM who had myocardial bridging diagnosed at coronary angiography.