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.