Left Ventricular Systolic Function Changes During Pump-Assisted Beating Heart Coronary Artery Bypass Graft Surgery: A Prospective Observational Study

Abstract

Background: There is a lack of information about the left ventricle (LV) systolic function changes during pump-assisted beating heart coronary artery bypass graft surgery (PACAB). This study aimed to study the changes in LV systolic function changes during PACAB. Methods: In this prospective, single-arm, observational study, 70 patients with American Society of Anesthesiologists physical status III or IV of either sex, aged 40-70 years, scheduled to undergo elective PACAB for isolated ischemic heart disease with EF >30% were included. We excluded patients with pregnancy, pericardial effusion, contraindications to transesophageal echocardiography (TEE), regional wall-motion abnormality of basal LV segments, pericardial effusion, right ventricular dysfunction, bundle branch blocks, and atrial fibrillation. After standard anesthesia induction, patients underwent PACAB. LV ejection fraction (EF), mitral annular plane systolic excursion (MAPSE), and tissue Doppler-derived peak mitral annular systolic velocity (s’) were recorded at various time points of surgery. Change in LV EF during surgery was the primary outcome variable of the study. Secondary outcome variables were complications and changes in MAPSE and s’. A repeated measure analysis of variance was used to compare the changes in LV systolic function at various stages of surgery. Results: Baseline LV EF was 47.73±9.91%. Compared to baseline, changes in EF during and after the surgery were not statistically and clinically significant. Changes in MAPSE and s’ during the surgery were not statistically significant. Complications included postoperative acute kidney injury, stroke, excess bleeding, and pneumonia. Conclusion: LV systolic function does not vary significantly during PACAB. However, more extensive randomized trials are required to apply these findings for routine use.