Ivabradine for patients with stable coronary artery disease and left-ventricular systolic dysfunction (BEAUTIFUL): a randomised, double-blind, placebo-controlled trial.

Kim Fox, Ian Ford, P Gabriel Steg, Michal Tendera, Roberto Ferrari, on behalf of the BEAUTIFUL Investigators.

Lancet. 2008. 6;372:807-816.

BACKGROUND: Ivabradine specifically inhibits the I(f) current in the sinoatrial node to lower heart rate, without affecting other aspects of cardiac function. We aimed to test whether lowering the heart rate with ivabradine reduces cardiovascular death and morbidity in patients with coronary artery disease and left-ventricular systolic dysfunction.

METHODS: Between December, 2004, and December, 2006, we screened 12 473 patients at 781 centres in 33 countries. We enrolled 10 917 eligible patients who had coronary artery disease and a left-ventricular ejection fraction of less than 40% in a randomised, double-blind, placebo-controlled, parallel-group trial. 5479 patients received 5 mg ivabradine, with the intention of increasing to the target dose of 7.5 mg twice a day, and 5438 received matched placebo in addition to appropriate cardiovascular medication. The primary endpoint was a composite of cardiovascular death, admission to hospital for acute  myocardial infarction, and admission to hospital for new onset or worsening heart failure. We analysed patients by intention to treat. The study is registered with ClinicalTrials.gov, number NCT00143507.

FINDINGS: Mean heart rate at baseline was 71.6 (SD 9.9) beats per minute (bpm). Median follow-up was 19 months (IQR 16-24). Ivabradine reduced heart rate by 6 bpm (SE 0.2) at 12 months, corrected for placebo. Most (87%) patients were receiving beta blockers in addition to study drugs, and no safety concerns were identified. Ivabradine did not affect the primary composite endpoint (hazard ratio 1.00, 95% CI 0.91-1.1, p=0.94). 1233 (22.5%) patients in the ivabradine group had serious adverse events, compared with 1239 (22.8%) controls (p=0.70). In a prespecified subgroup of patients with heart rate of 70 bpm or greater, ivabradine treatment did not affect the primary composite outcome (hazard ratio 0.91, 95% CI 0.81-1.04, p=0.17), cardiovascular death, or  admission to hospital for new-onset or worsening heart failure. However, it did reduce secondary endpoints: admission to hospital for fatal and non-fatal myocardial infarction (0.64, 95% CI 0.49-0.84, p=0.001) and coronary revascularisation (0.70, 95% CI 0.52-0.93, p=0.016).

INTERPRETATION: Reduction in heart rate with ivabradine does not improve cardiac outcomes in all patients with stable coronary artery disease and left-ventricular systolic dysfunction, but could be used to reduce the incidence of coronary artery disease outcomes in a subgroup of patients who have heart rates of 70 bpm or greater.

Heart rate as a prognostic risk factor in patients with coronary artery disease and left-ventricular systolic dysfunction (BEAUTIFUL): a subgroup analysis of a randomised controlled trial.

Kim Fox, Ian Ford, P Gabriel Steg, Michal Tendera, Michele Robertson, Roberto Ferrari, on behalf of the BEAUTIFUL investigators

Lancet. 2008. 6;372:817-821.

BACKGROUND: The BEAUTIFUL study assessed the morbidity and mortality benefits of the heart rate-lowering agent ivabradine. The placebo arm of the BEAUTIFUL trial was a large cohort of patients with stable coronary artery disease and left-ventricular dysfunction. We did a subanalysis of this placebo group to test the hypothesis that elevated resting heart rate at baseline is a marker for subsequent cardiovascular death and morbidity.

METHODS: The association of baseline resting heart rate with cardiovascular outcomes was analysed using Cox proportional hazard models for groups with a heart rate of 70 beats per min (bpm) or greater (2693 patients) versus less than 70 bpm (2745 patients). Additional analyses were done with finer categorisation of heart rate, and with heart rate as a continuous variable.

FINDINGS: After adjustment for baseline characteristics, patients with heart rates of 70 bpm or greater had increased risk for cardiovascular death (34%,  p=0.0041), admission to hospital for heart failure (53%, p<0.0001), admission to hospital for myocardial infarction (46%, p=0.0066), and coronary revascularisation (38%, p=0.037). For every increase of 5 bpm, there were increases in cardiovascular death (8%, p=0.0005), admission to hospital for heart failure (16%, p<0.0001), admission to hospital for myocardial infarction (7%, p=0.052), and coronary revascularisation (8%, p=0.034). The analysis of fine-groupings of heart rate suggests that the increase in mortality and heart failure outcomes rises continuously above 70 bpm, whereas the relation is less pronounced for coronary outcomes. For heart failure outcomes, the predictive value of resting heart rate was stronger for earlier events than for later events.

INTERPRETATION: In patients with coronary artery disease and left-ventricular systolic dysfunction, elevated heart rate (70 bpm or greater) identifies those at increased risk of cardiovascular  outcomes, with a differential effect on outcomes associated with heart failure and outcomes associated with coronary events.