The Role of Ivabradine in Cardiac Rehabilitation in Patients With Recent Coronary Artery Bypass Graft

Abstract

Background: Little is known about ivabradine in cardiac rehabilitation in patients with coronary artery bypass graft (CABG).

Methods: In this prospective, randomized study, suitable patients admitted for cardiac rehabilitation after recent CABG were randomized to ivabradine 5 mg twice a day + standard medical therapy including bisoprolol 1.25 mg once daily (group I-BB, n = 38) or standard medical therapy including bisoprolol 2.5 to 3.75 mg once daily (group BB, n = 43). Patients were evaluated at admission, discharge, and 3 months. The primary end point was improvement in functional status, and other end points were improvement in diastolic function and recovery of systolic function. End points were assessed by distance covered in 6-minute walking test (6MWT), percentage with normal diastolic function, and percentage increase in left ventricular ejection fraction (LVEF).

Results: Cardiac rehabilitation improved functional capacity in both groups. In group BB, distances covered in the 6MWT at admission, discharge, and 3 months were 215 ± 53, 314 ± 32, and 347 ± 42 m, respectively. Corresponding distances in group I-BB were 180 ± 91, 311 ± 58, and 370 ± 55 m. Normal diastolic function was restored in I-BB patients, increasing from 24% at admission to 50% and 79% at discharge and 3 months; in BB patients, it decreased from 23% to 19% and 16%. The LVEF improved in I-BB patients, from 57% ± 3% at admission to 62% ± 4% at discharge and 66% ± 3% at 3 months, while remaining unchanged in BB patients (57% ± 3%, 59% ± 4%, and 59% ± 3%).

Conclusion: Adding ivabradine to low-dose bisoprolol during cardiac rehabilitation in patients with CABG improved functional capacity, enhanced recovery of systolic function, and reduced diastolic dysfunction.

Keywords: 6-minute walking test; beta-blocker; cardiac rehabilitation; coronary artery bypass graft; diastolic dysfunction; ivabradine.