Abstract 16912: Cardiac Microstructural Associations With Pulse Pressure Differ by Sex

Background: Alterations in the orientation and integrity of myocardial fibers can be assessed using ultrasonic image analysis. The ability to detect such microstructural abnormalities may shed light on sex differences in the progression from common risk factors, such as blood pressure elevation, to overt cardiac disease. Methods: In a community-based cohort of N=2510 adults (age 66±9 years, 56% women) without overt cardiovascular disease, we evaluated whether a novel echocardiography-based assessment of left ventricular myocardial microstructure, the signal intensity coefficient (SIC), could detect tissue-level alterations that are associated with blood pressure parameters including pulse pressure, an indirect measure of large artery stiffness and established correlate of adverse cardiac outcomes. Results: We observed that for every 10 mmHg increase in pulse pressure, women had a significantly greater degree of cardiac microstructural alteration (coeff 0.07; s.e. 0.02, P<0.001), whereas this age-adjusted association was not seen in men (coeff -0.01; s.e. 0.02, P=0.65) ( Figure ). Although we observed similar results for systolic, diastolic, and mean arterial pressure, the sex interaction terms were non-significant (P>0.05) for these other parameters. Conclusion: A novel index of myocardial tissue alteration is associated with incremental elevations in pulse pressure in women but not in men. Further research is needed to examine the extent to which cardiac microstructural abnormalities may mediate the risks for cardiac disease in women, particularly those conditions involving large artery stiffening such as heart failure with preserved ejection fraction.