Myocardial bridging, a frequent component of the hypertrophic cardiomyopathy phenotype, lacks systematic association...

Area of Science:

• Cardiovascular Pathology
• Cardiac Morphology
• Hypertrophic Cardiomyopathy Research

Background:

• Myocardial bridging (CB) of the left anterior descending coronary artery is a congenital anomaly.
• Its clinical significance in hypertrophic cardiomyopathy (HCM) remains debated.
• Left ventricular hypertrophy is a hallmark of HCM.

Purpose of the Study:

• To investigate the prevalence and characteristics of myocardial bridging (CB) in hearts with hypertrophic cardiomyopathy (HCM).
• To compare the occurrence of CB in HCM with control groups.
• To assess the association between CB and modes of death in HCM patients.

Main Methods:

• A morphological analysis was conducted on 255 hearts, including 115 with HCM and 140 controls.
• Prevalence and depth of coronary artery bridges (CBs) were assessed.
• Statistical comparisons were made between HCM patients and control groups, and among different death categories within the HCM cohort.

Main Results:

• Coronary artery bridges (CBs) were significantly more common in HCM hearts (41%) compared to non-HCM controls (21%) and patients with aortic stenosis and left ventricular hypertrophy (12%).
• CBs were present in 43% of HCM sudden death cases, 37% of heart failure cases, and 36% of other death modes.
• Deeply embedded CBs (> or =2 mm) showed no significant difference in frequency between sudden death and heart failure death groups in HCM patients.

Conclusions:

• Myocardial bridging (CB) is a frequent finding in phenotypically expressed hypertrophic cardiomyopathy (HCM) and is more prevalent than in other conditions with or without left ventricular hypertrophy.
• A direct, systematic association between CB and HCM-related sudden death was not evident in this study.
• The findings suggest that CB might contribute to increased risk in select HCM patients, warranting individualized clinical consideration.