Echocardiographic Assessment of Diastolic Dysfunction and the Efficacy of Ivabradine Therapy Post-CABG Surgery

Background: Diastolic dysfunction is common in patients undergoing coronary artery bypass grafting (CABG). This study investigates the effects of ivabradine, a selective inhibitor of the cardiac pacemaker current (I f ), on diastolic function following CABG. Materials and Methods: This prospective cohort study included sixty adult patients with coronary artery disease and preserved systolic left ventricular function but with diastolic dysfunction (DD). Patients were randomly assigned into two groups: Group I received standard postoperative medical therapy with ivabradine (5.0–7.5 mg BID), initiated early after surgery, whereas Group II received standard postoperative medical therapy alone. Exclusion criteria included those having concomitant valvular or pericardial disease, atrial fibrillation, and contraindications to ivabradine. Echocardiographic parameters, including left atrial dimensions, filling velocities, tissue Doppler imaging, and deceleration time, were assessed preoperatively, at 7 days postoperatively and at 90 days. Results: Group I exhibited significant reductions in blood pressure and hematocrit levels and elevated levels of creatine kinase-MB and LDH, along with reductions in left atrial volume, aortic diameter, and right ventricular diameter, whereas Group II showed decreased platelet counts, ejection fraction, and isovolumic relaxation time; an improvement in diastolic function, and lack of tendency toward normalization of DD. Conclusion: The addition of ivabradine to standard postoperative therapy may enhance diastolic function in patients post-CABG surgery. Further prospective studies with larger cohorts are warranted to confirm these findings.