Abstract 13944: Biracial Proteomic Profiling Reveals Novel Candidate Pathways in Left Ventricular Hypertrophy and Incident Heart Failure Specific to Black Individuals

Abstract

Background: Increased left ventricular (LV) mass is associated with future adverse cardiovascular events including heart failure (HF). Both increased LV mass and HF disproportionately affect black individuals. To understand the mechanisms that drive disease, particularly in black individuals, we undertook a proteomic screen in a black cohort and compared it to a white cohort. Methods: We measured 1305 plasma proteins using an aptamer-based proteomic platform (SOMAscan™) in 1772 black participants in the Jackson Heart Study (JHS) with available baseline LV mass as assessed by 2D echocardiography, as well as 1600 free of HF with follow-up assessment of incident cases. Mean follow-up time was 11 years; 152 cases of incident HF hospitalization were identified. Models were adjusted for age, sex, body mass index, estimated glomerular filtration rate (as calculated by CKD-EPI equation), systolic blood pressure, hypertension treatment, presence of diabetes, total/HDL cholesterol, prevalent coronary disease, and current smoking status. Incident HF models were also adjusted for incident coronary heart disease. We then compared protein associations in JHS to those observed in whites from the Framingham Heart Study (FHS) to examine significant differences. Results: In JHS, there were 112 proteins associated with LV mass and 10 proteins associated with incident HF hospitalization with FDR <5%. Several proteins showed expected associations with both LV mass and HF, including N-terminal pro-BNP (β = 0.04 [0.02, 0.05], p = 1.0 x 10 -8 , HR = 1.46 [1.20, 1.79], p = 0.0002). The strongest association with LV mass was more novel: leukotriene A4 hydrolase (LKHA4) (β = 0.05 [0.04, 0.06], p = 2.6 x 10 -15 ). Conversely, Fractalkine/CX3CL1 showed a novel association with incident HF (HR = 1.32 [1.14, 1.54], p = 0.0003). While proteins like Cystatin C and N-terminal pro-BNP showed consistent effects in FHS, LKHA4 and Fractalkine were significantly different. Conclusions: We identify several novel biological pathways specific to black individuals hypothesized to contribute to the pathophysiologic cascade of LV hypertrophy and incident HF including LKHA4 and Fractalkine. Further studies are needed to validate these results and elucidate the detailed underlying mechanisms.