Heart rate manipulation in dilated cardiomyopathy: Assessing the role of Ivabradine.

Background: Heart rate (HR) reduction is of benefit in chronic heart failure (HF). The effect of heart rate reduction using Ivabradine on various echocardiographic parameters in dilated cardiomyopathy has been less investigated.

Methods: Of 187 patients with HF (DCM, NYHA II-IV, baseline HR>70/min), 125 patients were randomized to standard therapy (beta blockers, ACEI, diuretics, n=62) or add-on Ivabradine (titrated to maximum 7.5mg BD, n=63). Beta-blockers were titrated in both the groups.

Results: At 3 months both groups had improvement in NYHA class, 6min walk test, Minnesota Living With Heart Failure (MLWHF) scores and fall in BNP, however the magnitude of change was greater in Ivabradine group. Those on Ivabradine also had lower LV volumes, higher LVEF (28.8±3.6 vs 27.2±0.5, p=0.01) and more favorable LV global strain (11±1.7vs 12.2±1.1, p=<0.001), MPI (0.72±0.1 vs 0.6±0.1, p=<0.001), LV mass (115.2±30 vs 131.4±35, p=0.007), LV wall stress (219.8±46 vs 238±54) and calculated LV work (366±101 vs 401±102, p=0.05). The benefit of Ivabradine was sustained at 6 months follow up. The % change in HR was significantly higher in Ivabradine group (-32.2% vs -19.3%, p=0.001) with no difference in blood pressure. Resting HR<70/min was achieved in 96.8% vs 27.9%, respectively in the two groups.

Conclusion: Addition of Ivabradine to standard therapy in patients with DCM and symptomatic HF and targeting a heart rate<70/min improves symptoms, quality of life and various echocardiographic parameters.