Abstract 11691: Self-Reported Sodium Intake Identifies a Sodium Vulnerable State With Increased Response to Spironolactone in HFpEF

Abstract

Introduction: Asking patients about sodium intake is standard practice in heart failure (HF). Hypothesis: Self-reported sodium intake in HF with preserved ejection fraction (HFpEF) reflects a vulnerability to sodium intake driven by aldosterone. Methods: The TOPCAT trial registered self-reported sodium intake at baseline. Cox-regression and linear-mixed models were used to assess the relationship between self-reported sodium intake and outcome. Interaction analysis between self-reported sodium intake and the treatment effect of spironolactone on HF-outcome, blood pressure (BP), dyspnea and edema at follow-up were used to assess sodium vulnerability mediated by an aldosterone effect. Results: Self-reported sodium intake of 1748 HFpEF patients included in TOPCAT were divided according to tertiles of sodium intake (47% low, 35% moderate and 18% reported high sodium intake). After covariate adjustment lower self-reported sodium intake associated with higher risk for HF-admission (p=0.009). Patients with a lower sodium intake demonstrated higher E-wave and LV-end diastolic volume and higher estimated plasma volume (p<0.001). Lower sodium intake was associated with a larger treatment effect of spironolactone on HF-admission (HR=0.69, 95%CI 0.53-0.91 vs highest tertile HR=1.37 95%CI 0.79-2.38, p-interaction=0.030). Additionally, linear-mixed models indicated larger BP-reduction (Figure) and larger reduction in dyspnea and edema (p-interaction all<0.001) in patients with lower sodium intake receiving spironolactone. Conclusions: Low self-reported sodium in HFpEF is associated with volume status and higher risk of HFH. The more pronounced treatment effect with spironolactone on HF-outcome, BP and volume status in patients with the lowest self-reported sodium intake potentially suggests that low self-reported sodium intake is an indicator of a sodium vulnerable, potentially aldosterone driven, state.