Prognostic Value of Resting Heart Rate and Heart Rate Recovery in Acute Decompensated Heart Failure

Abstract

Background: Acute decompensated heart failure (ADHF) remains a problem of public health concern. Better prognostication is needed to predict outcomes in these patients. Resting heart rate (HR) and HR recovery (HRR) have been proposed as prognostic markers for future events. Materials and Methods: Twenty-five patients admitted for ADHF were enrolled. Baseline demographic data and routine investigations were noted for all. After medical stabilization, before discharge, a 6-min walk test (6-MWT) was performed for all patients. Resting HR at the start, maximum HR achieved, chronotropic reserve, and hearing rate recovery was observed 1 min after completing the exercise. All patients were followed for the appearance of a primary composite outcome consisting of death, heart transplant, or hospitalization for HF. Results: Primary composite outcome occurred in 6 (24%) patients, including 3 (12%) deaths and 3 (12%) HF hospitalizations. The patients who had the primary outcome had a trend toward a shorter distance of walking of 6 min (154.33 ± 51.84 vs. 210.53 ± 78.62, P = 0.16). Resting HR was significantly higher among patients with primary outcome (113.00 ± 17.74 vs. 89.58 ± 16.25, P ≤ 0.01). HRR and chronotropic reserve were significantly lower in patients with primary outcome (7.33 ± 1.75 vs. 17.42 ± 9.47, P < 0.01 and 15.00 ± 11.93 vs. 34.94 ± 19.81, P = 0.02; respectively). A resting HR of 109/min, HRR of 9/min, and chronotropic reserve of 20/min had sensitivity/specificity for predicting the primary outcome of 83.33%/89.47%, 84.21%/83.33%, and 84.21% a/as 83.33%, respectively. Conclusions: Elevated resting HR, decreased HR reserve, and decreased chronotropic reserve are associated with hospital readmissions and decreased event-free survival in patients with ADHF. Resting HR is especially helpful in this regard given the simplicity and ease of its assessment.