Abstract 16646: Invasive Assessment of Myocardial Bridging in Women and Men Presenting With Angina in the Absence of Obstructive Coronary Artery Disease
Introduction: Up to 20% of patients with angina undergoing coronary angiography have no obstructive coronary artery disease (CAD). Myocardial bridging, while common in the population, is a potential cause of angina in this subset of patients.
Hypothesis: We studied sex differences in the structural and hemodynamic characteristics of myocardial bridging in patients with angina in the absence of obstructive CAD.
Methods: We identified a myocardial bridge (MB) in the left anterior descending artery by intravascular ultrasound (IVUS) in 62 women and 24 men with angina in the absence of obstructive CAD. A MB was defined as an echolucent half-moon sign and/or ≥10% systolic compression. We evaluated MB-related parameters, including total MB length, % arterial compression, and halo thickness, as well as minimum lumen area and plaque burden. Hemodynamic testing of the MB was performed using an intracoronary pressure/Doppler flow wire at rest and during dobutamine stress. We calculated diastolic fractional flow reserve (dFFR) (the ratio of diastolic intracoronary pressure divided by aortic pressure), as well as peak Doppler flow velocity. An abnormal dFFR was defined as ≤0.76 during dobutamine stress.
Results: When compared with women, men had a longer length of myocardial bridging, more systolic compression, and a greater plaque burden proximal to the MB. There was no difference in halo thickness or MLA. There was also no sex difference in the dFFR or peak Doppler velocity change with stress (figure).
Conclusions: While women are more likely than men to have angina in the absence of obstructive CAD, in patients with a MB as a possible cause of their angina, men have a longer length of bridge, more systolic compression, and greater plaque burden proximal to the MB than women. Interestingly, these more severe MB features in men do not result in more hemodynamic significance. Further research is needed to understand this sex difference.
Author Disclosures: V.S. Pargaonkar: None. I. Schnittger: None. S. Tanaka: None. R. Yamada: None. T. Kimura: None. I. Rogers: None. J.A. Tremmel: None.
- © 2015 by American Heart Association, Inc.