Abstract 14230: Integration of Vascular Phenotyping With Metabolomic Profiling in Black Subjects With Heart Failure With Reduced Ejection Fraction

Abstract

Introduction: Impaired vascular function in blacks contributes to a higher risk of heart failure (HF) compared to other race/ethnicities. Hypothesis: Black patients with HF with reduced ejection fraction (HFrEF) will have worse digital microvascular function measured using peripheral arterial tonometry (PAT). High resolution metabolomics profiling will identify novel biomarkers of vascular function. Methods: PAT was used to estimate the reactive hyperemia index (RHI) in blacks and whites with HFrEF (N=154, age: 53.7 ± 13.0 yrs, 48.7% female, 61.0% black) and healthy controls (N=200, age: 43.2 ± 14.0 yrs, 47.0% female, 27.0% black). Linear regression was used to determine if race was associated with RHI after adjustment for traditional CV risk factors. High-resolution plasma metabolomics profiling and pathway analysis, followed by metabolite confirmation with mass spectrometry were used to derive a metabolomics score (MS) from metabolites that were significantly associated with RHI, different between blacks and whites, and attenuated the association of black race with RHI. Results: Black subjects were younger in both the HFrEF and control cohorts. Blacks with HFrEF were more likely to have nonischemic HF and hypertension, more likely to be on hydralazine-nitrates and diuretics. RHI was lower in blacks than whites both in subjects with HFrEF (1.8 ± 0.5 vs. 2.0 ± 0.5, P=0.02) and in healthy controls (2.1 ± 0.5 vs. 2.4 ± 0.5, P=0.003). Black race was independently associated with lower RHI (adjusted β=-0.221, P=0.03). MS comprising metabolites representative of cardiac cachexia (3-Methyl-Histidine, L-Histidine, Creatinine), vascular collagen turnover (4-hydroxyproline), purine metabolism and oxidative stress (uric acid) attenuated the association of black race with RHI by 49.8%. Conclusion: Integration of vascular phenotyping with metabolomic profiling reveals a novel MS that attenuates the association of black race with impaired microvascular function.