Heart rate reduction with ivabradine and health related quality of life in patients with chronic heart failure: results from the SHIFT study

Abstract

AIMS: Heart failure (HF) has a major impact on health-related quality of life (HQoL). The aim was to evaluate whether heart rate (HR) reduction with ivabradine can translate into increased HQoL in parallel to a reduction of primary outcomes in SHIFT. METHODS AND RESULTS: In symptomatic patients with systolic HF treated with recommended background therapy, HQoL was assessed by Kansas City Cardiomyopathy Questionnaire (KCCQ) containing the following dimensions: overall summary score (OSS) and clinical summary score (CSS), analysed at baseline, and 4, 12, and 24 months, and last post-baseline visit. A total of 1944 patients (968 ivabradine, 976 placebo) were evaluated. At 12 months, incidence of clinical events (cardiovascular death or hospital admission for HF) was inversely associated with KCCQ scores. Ivabradine reduced HR by 10.1 bpm (placebo-corrected, P < 0.001) and improved KCCQ by 1.8 for CSS and 2.4 for OSS (placebo-corrected, P = 0.02 and P < 0.01, respectively); these changes were associated with the change in HR for both CSS (P < 0.001) and OSS (P < 0.001). The relationship was found in both allocation groups though the changes were more pronounced in the ivabradine group. Health-related quality of life at follow-up was better preserved in the ivabradine group compared with placebo; poorest outcomes were seen in the placebo group with lowest KCCQ scores (<50). CONCLUSION: In patients with systolic HF, low HQoL is associated with an increased rate of cardiovascular death or hospital admission for HF. Reduction in HR with ivabradine is associated with improved HQoL. The magnitude of HR reduction is related to the extent of improvement in HQoL.