Abstract MP71: The Association of Vascular Endothelial Tone and Function by Digital Peripheral Arterial Tonometry with Left Ventricular Structure and Function by Cardiac MRI

Objectives: Higher vascular endothelial tone and impaired endothelial function as assessed by digital peripheral arterial tonometry (PAT) have been associated with increased cardiovascular morbidity and mortality. However, their relation to left ventricular mass (LVM), geometry and systolic function is not known. We examined this relation in a community-based cohort of African Americans. Methods: This study included participants of the Jackson Heart Study who had digital PAT and cardiac magnetic resonance imaging (CMRI) evaluated between 2007- 2013. LVM was adjusted for body size by indexing to height2.7 (LVMI). LVMI was log-transformed within sex and used in the analyses. Age- and sex-adjusted Pearson’s correlations were used to relate baseline pulse amplitude (BPA) and reactive hyperemia index (RHI) (markers of endothelial tone and endothelial function respectively) to LVMI, LV systolic and diastolic volumes (LVSV and LVDV), and stroke volume (SV) by CMRI. Using multivariable adjusted stepwise linear regression with age and sex forced into the model, the relation of PAT parameters to CMRI LV structure and function was evaluated adjusting for body mass index, systolic blood pressure, diabetes mellitus, and total cholesterol: HDL ratio. Results: The study population consisted of 440 participants [mean age 59 ± 10 years, 263 (60%) women]. Higher BPA (increased endothelial tone) was significantly and positively correlated with log-LVMI (0.272; p <0.001). Higher RHI (improved endothelial function) was significantly and negatively correlated with log-LVMI (-0.114; p <0.018). In age-sex adjusted models both higher BPA (β = 0.064, SE = 0.011, p < 0.001) and lower RHI (β = -0.069, SE = 0.029, p = 0.018) were significantly related to higher log-LVMI. In the multivariable analyses higher BPA (β = 0.022, SE = 0.010, p = 0.023) but not RHI (p > 0.05) was significantly associated with higher log-LVMI. BPA explained approximately 11% of the total variation of log-LVMI. PAT parameters were not significantly associated with LV volumes or cardiac function parameters in the multivariable analysis. Conclusions: In a community-based sample of African Americans higher endothelial tone measured by digital PAT was significantly associated with higher LVMI by CMRI after adjusting for traditional risk factors. Better endothelial function was correlated with lower LVMI and was significantly associated with lower LVMI in the age-sex adjusted model but not the fully adjusted model. These findings suggest that endothelial tone may be one of the potential determinants of LV hypertrophy in African Americans.