Abstract 18846: Heart Rate Reserve, a Prognostic Marker for Heart Failure Hospitalizations and Adverse Outcomes

Abstract

Introduction: Heart Failure hospitalization (HFH) is a major clinical event and economic burden. Heart Rate Reserve (HRR), a marker of chronotropic incompetence is associated with mortality, but its prognostic value in HF progression is unknown. Methods: In this multi-center study, HF patients with NYHA class 2-3, in sinus rhythm, on stable medical therapy underwent a cardiopulmonary exercise test (CPET) from 2008-2013 at Columbia University Medical Center and were prospectively followed for 3 endpoints: HFH, inotrope dependence or worse, and heart replacement therapy or death (HRT-D). Various clinical variables including HRR were evaluated and included in risk score models. The models with highest significance were validated in an independent cohort from Montefiore Medical Center Results: In the derivative cohort of 135 patients, low pVO2, HRR, and LVEF were significantly associated with all 3 endpoints. Using ROC analysis, HRR<45% was equivalent to pVO2<14 ml/kg/min in predicting all outcomes. The model using LVEF<30%, pVO2<14 ml/kg/min and HRR<45% as binary cut-offs (total score: 0-3) was able to stratify patients into different risk strata for freedom from HFH (p<0.001, Fig-1), freedom from inotrope dependence or worse (p<0.001) and from HRT-D (p<0.001, Fig-2) at 1 year. A simpler model using LVEF<30% and HRR<45% (total score: 0-2) was also able to risk stratify patients (p<0.001). These results were validated in an independent cohort of 294 patients. Conclusions: HRR is a strong predictor of outcomes in advanced HF. If a metabolic cart is unavailable, a simple risk score using HRR<45% and LVEF<30% alone can help clinicians identify patients at highest risk for HFH.