Clinical Outcomes of Ivabradine as Adjunctive Therapy in Heart Failure Patients with Left Bundle Branch Block

Abstract

Background Heart failure (HF) with reduced ejection fraction (HFrEF) and left bundle branch block (LBBB) is associated with ventricular dyssynchrony, impaired cardiac function, frequent hospitalizations, and increased mortality. Ivabradine selectively reduces heart rate by inhibiting the If current in the sinoatrial node and has demonstrated clinical benefits in selected HF patients. However, evidence regarding its effectiveness in patients with concomitant LBBB remains limited. Aim To evaluate the clinical outcomes of ivabradine as adjunctive therapy in heart failure patients with left bundle branch block. Methods A retrospective observational study was conducted at VSS Institute of Medical Sciences and Research (VIMSAR), Burla, over 24 months. Medical records of 100 patients with HFrEF and LBBB receiving standard guideline-directed medical therapy (GDMT) were reviewed. Patients were divided into those receiving ivabradine plus GDMT (n=50) and GDMT alone (n=50). Clinical parameters, NYHA functional class, heart rate, left ventricular ejection fraction (LVEF), hospitalization rates, and mortality were compared. Results Patients receiving ivabradine demonstrated significantly greater reduction in resting heart rate (−18.4 ± 6.2 bpm vs −7.1 ± 4.8 bpm, p<0.001), improvement in LVEF (7.6 ± 3.2% vs 3.1 ± 2.5%, p<0.001), and better NYHA class improvement (p=0.002). Heart failure-related hospitalizations were significantly lower in the ivabradine group (18% vs 36%, p=0.041). Mortality was lower in the ivabradine group (8% vs 16%), although the difference did not reach statistical significance (p=0.21). Conclusion Ivabradine as adjunctive therapy was associated with improved functional status, better heart rate control, enhanced left ventricular function, and reduced hospitalization among heart failure patients with LBBB.