Myocardial bridging of the left anterior descending coronary artery as a risk factor for atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy: a matched case–control study

Background Myocardial bridging (MB) is associated with various forms of arrhythmia. However, whether MB is a risk factor for atrial fibrillation (AF) in patients with hypertrophic obstructive cardiomyopathy (HOCM) remains unknown. This study aimed to identify the relationship between myocardial bridging of the left anterior descending coronary artery (MB-LAD) and AF in patients with HOCM. Methods We reviewed the medical records of 1925 patients diagnosed with HOCM at Fuwai Hospital from January 2012 to March 2019. Patients with coronary artery disease, a history of heart surgery, and those who had not been subjected to angiography were excluded. Finally, 105 patients with AF were included in this study. The control group was matched in a ratio of 3:1 based on age and gender. Results Forty-three patients were diagnosed with MB-LAD in this study. The presence of MB was significantly higher in patients with AF than in those without AF (19.0% vs. 7.3%; p = 0.001), although MB compression and MB length did not differ between the two groups. In conditional multivariate logistic analysis, MB (odds ratio [OR] 2.33; 95% confidence interval [CI] 1.08–5.01; p = 0.03), pulmonary arterial hypertension (OR 2.63; 95% CI 1.26–5.47; p = 0.01), hyperlipidemia (OR 1.83; 95% CI 1.12–3.00; p = 0.016), left atrial diameter (OR 1.09; 95% CI 1.05–1.13; p < 0.001), and interventricular septal thickness (OR 1.06; 95% CI 1.003–1.12; p = 0.037) were independent risk factors for AF in patients with HOCM. Conclusions The presence of MB is an independent risk factor for AF in patients with HOCM. The potential mechanistic link between MB and the development of AF warrants further investigation.