Should we SHIFT our thinking about digoxin? Observations on ivabradine and heart rate reduction in heart failure

The importance of heart rate in the pathophysiology of heart failure with reduced LVEF has recently attracted attention. In particular, the findings of the Systolic Heart failure treatment with the I-f inhibitor ivabradine Trial (SHIFT) have put special emphasis on heart rate reduction with ivabradine for improvement in clinical outcomes. Of course, there is a much older drug that reduces heart rate, i.e. digoxin. In this short commentary, we retrospectively analyse the Digitalis Investigation Group (DIG) Trial looking at the primary composite endpoint used in SHIFT (i.e. cardiovascular death or hospital admission for worsening heart failure) and compare the effect of digoxin on this endpoint with that of ivabradine. A remarkably similar risk reduction in the composite outcome and in its components appears evident among patients receiving the active treatment in both studies (although ivabradine was added to a beta-blocker, whereas digoxin was not). This raises the question of whether the Cardiological community dismissed digoxin too readily and if we should reappraise its potential role in the treatment of heart failure.