Comparison between ivabradine and low-dose digoxin in the therapy of diastolic heart failure with preserved left ventricular systolic function

Abstract

Multicenter trials have demonstrated that in patients with sinus rhythm ivabradine is effective in the therapy of ischemic heart disease and of impaired left ventricular systolic function. Ivabradine is ineffective in atrial fibrillation. Many patients with symptomatic heart failure have diastolic dysfunction with preserved left ventricular systolic function, and many have asymptomatic paroxysmal atrial fibrillation. Ivabradine is not indicated in these conditions, but it happens that it is erroneously used. Digoxin is now considered an outdated and potentially dangerous drug and while effective in the mentioned conditions, is rarely used. The aim of the study was to compare the therapeutic effects of ivabradine in diastolic heart failure with preserved left ventricular systolic function. Patients were assigned to ivabradine or digoxin according to a randomization cross-over design. Data were single-blind analyzed. The analysis was performed using an intention-to-treat method. Forty-two coronary patients were selected. In spite of maximally tolerated therapy with renin-antagonists, diuretics and β-blockers, they had congestive diastolic heart failure with preserved systolic function. Both ivabradine and digoxin had positive effects on dyspnea, Nterminal natriuretic peptide, heart rate, duration of 6-min. walk-test and signs of diastolic dysfunction, but digoxin was high-statistically more effective. Side-effects were irrelevant. Data were obtained in a single-center and from 42 patients with ischemic etiology of heart failure. The number of patients is small and does not allow assessing mortality. In coronary patients with symptomatic diastolic heart failure with preserved systolic function low-dose digoxin was significantly more effective than ivabradine and is much cheaper. One should be more critical about ivabradine and low-dose digoxin in diastolic heart failure. To avoid possible negative effects on the cardiac function and a severe reduction of the cardiac output the resting heart rate should not be decreased to <65 beats/min.

Keywords: diastolic heart failure; digoxin; ivabradine.

Figure 1.

Heart rate before and after therapy. HR, heart rate (beats/min); B, before therapy with test drugs; DIG, digoxin; IVA, ivabradine; All, all patients; AF, patients with asymptomatic paroxysmal atrial fibrillation; SR, patients with sinus rhythm.

Figure 2.

Maximal heart rate during the 6-min walk test, before and after therapy. HR, heart rate (beats/min); B, before therapy with test drugs; DIG, digoxin; IVA, ivabradine; All, all patients; AF, patients with asymptomatic paroxysmal atrial fibrillation; SR, patients with sinus rhythm.

Figure 3.

Left atrial index before and after therapy. LA, left atrial index (mL/m²); B, before therapy with test drugs; DIG, digoxin; IVA, ivabradine; All, all patients; AF, patients with asymptomatic paroxysmal atrial fibrillation; SR, patients with sinus rhythm.