Effect of Heart Failure With Preserved Ejection Fraction on Nitric Oxide Metabolites

Endothelial function may be deranged in heart failure with preserved ejection fraction (HFpEF). Serum NO-derived metabolites (NO_m) might provide a biochemical surrogate of endothelial function in patients with heart failure (HF). We measured serum NO_m in 415 participants in the Penn HF Study. Participants with HFpEF (n = 82) and those whose EF had recovered (Recovered-HF, n = 125) were matched 1:1 to heart failure with reduced ejection fraction (HFrEF) participants based on age, gender, race, tobacco use, and eGFR. Serum NO_m levels were quantified after chemical reduction coupled with gas-phase chemiluminescence detection. After adjustment for matching covariates and BMI, HFpEF (34.5 μM; interquartile range [IQR] 25.0, 51.5) participants had lower NO_m levels than HFrEF (41.0 μM; IQR 28.3, 58.0; ratio of HFpEF:HFrEF 0.82, 95% confidence interval [CI] 0.67 to 0.99; p = 0.04), which further decreased when adjusted for covariates that affect endothelial function (ratio 0.79, 95% CI 0.65 to 0.98; p = 0.03). There were no differences between HFrEF (34.0; IQR 25.3, 49.0) and matched Recovered-HF (36.0 μM; IQR 25.0, 55.0) or HFpEF and Recovered-HF. Age (+21%/10-year increase, p <0.001) and black race (-28%, p = 0.03) associated with NO_m in HFpEF, whereas age (+11%/10-year increase, p = 0.03), current tobacco use (+67%, p = 0.01), and eGFR (p = 0.01) associated with NO_m in Recovered-HF. In conclusion, HFpEF participants have reduced NO_m compared with HFrEF in this matched cohort. This might suggest either compromised endothelial function or poor dietary intake. Black race was associated with lower NO_m in HFpEF.