Abstract 4371653: Racial Differences in Right Ventricular Load Adaptation: Pulmonary Arterial Compliance and RV Stroke Work Index in Right Heart Catheterization and Transthoracic ECHO

Introduction: Racial disparities significantly influence cardiovascular outcomes, particularly in pulmonary hypertension (PH). African American (AA) patients often demonstrate distinct patterns in right ventricular (RV) adaptation compared to White patients. Key hemodynamic indicators such as Pulmonary Arterial Compliance (PAC) and RV Stroke Work Index (RVSWI) are critical markers of RV load management, yet racial differences in these metrics merit further investigation. Research Questions: We hypothesized that African American patients would exhibit reduced pulmonary arterial compliance and altered RV stroke work despite similar hemodynamic pressures compared to White patients. Methods: We retrospectively analyzed 249 patients who underwent right heart catheterization (RHC) at a community-based heart failure clinic from 2017–2020. Patients were categorized as AA (n=62) or White (n=190). PAC was calculated as stroke volume divided by pulmonary artery pulse pressure, and RVSWI was determined using standard invasive hemodynamic data and calculated echo measurements. Statistical comparisons were performed using independent t-tests, with significance set at p < 0.05. Results: Mean RVSWI was similar between AA (9.37 gm/m2/beat) and White (9.82 gm/m2/beat) patients (p = 0.61). However, PAC was significantly lower in AA patients (1.06 mL/mmHg) compared to White patients (1.47 mL/mmHg, p = 0.0005), indicating significantly stiffer pulmonary vasculature among AA individuals. Conclusion: African American patients demonstrate significantly reduced pulmonary arterial compliance, suggesting a distinct pathophysiological adaptation to pulmonary load despite similar RV stroke work indices. These findings highlight the need for further investigation into racial differences in RV-pulmonary vascular interaction, potentially influencing tailored diagnostic and therapeutic strategies. Future research should explore mechanistic contributors and consider whether these physiologic differences warrant race-conscious risk stratification or therapy optimization.