Abstract 21000: Interaction Between Mineralocorticoid Receptor Antagonist and Soluble ST2 in Heart Failure With Preserved Ejection Fraction

Background: Mineralocorticoid receptor antagonist (MRA) has a potential to improve clinical outcomes in heart failure with preserved ejection fraction (HFpEF), since MRA inhibits progression of myocardial hypertrophy and fibrosis. Soluble ST2 (sST2) is a novel biomarker reflecting myocardial stress and fibrosis. MRA plays a role in the interleukin-33/ST2 signaling modulation. Hypothesis: We hypothesized that the effect of MRA on clinical outcomes in HFpEF differed by sST2 level. This study aimed to evaluate the relationship between sST2 and clinical outcomes and to test for an interaction between the effect of MRA and sST2 level. Methods: 191 patients with acute decompensated HF and EF ≥50% were prospectively enrolled. The primary endpoint was major adverse cardiovascular events (MACE), which included death from cardiovascular disease, unplanned hospitalization for heart failure, acute coronary syndrome and stroke. Results: During follow-up (421±258days), 53 patients (27.7%) met endpoints. In a multivariable analysis, use of MRA and sST2 level were significantly associated with the endpoint (HR 0.48, 95%CI 0.26-0.86, P=0.01, HR 1.02, 1.01-1.03, P=0.01). Patients were divided into 4 groups according to use of MRA and a cutoff value of sST2 (18.5 ng/ml) determined by ROC analysis. Estimated event rate for MACE were significantly higher in patients without MRA compared with those in patients with MRA regardless of category of sST2 level. In a multivariable analysis, MRA was not a significant predictor of outcome in high sST2 group (HR 0.62, 0.28-1.30, P=0.21), whereas MRA was significantly associated with improved outcome in low sST2 group (HR 0.37, 0.13-0.91, P=0.03). Conclusion: The present study showed that higher sST2 level was associated with worse prognosis and predictive of less response to MRA treatment in patients with HFpEF, which suggests that sST2 may be used to predict response to MRA treatment.