A Randomized Controlled Trial of Intra-Aortic Adenosine Infusion Before Release of the Aortic Cross-Clamp During Coronary Artery Bypass Surgery

Abstract

Objectives: To assess the feasibility, safety, and potential useful effect of adenosine as a postconditioning agent in patients undergoing coronary artery bypass grafting surgeries.

Design: Prospective randomized controlled study.

Setting: University hospital.

Participants: The study comprised 60 patients scheduled for coronary artery bypass grafting surgery.

Interventions: Adenosine (postconditioning group) or placebo (control group). Adenosine infusion (150 µg/kg/min) for 10 minutes via a cardioplegia needle into the aortic root was started 10 minutes before aortic cross-clamp removal.

Measurements and main results: Compared with the control group, ejection fraction, fractional shortening, cardiac index (2.9 ± 0.3 v 2.2 ± 0.3 L/min/m², p = 0.032 at 60 min postbypass) and diastolic function indices were significantly better in the postconditioning group at most time points in the postbypass period. Cardiac troponin I and creatine kinase-MB release and the inotropic score were significantly lower in the postconditioning group at most time points in the postoperative period. The need for intra-aortic balloon and epicardial pacing were comparable in both groups, whereas incidence of arrhythmia, duration of postoperative mechanical ventilation, and intensive care unit and total hospital stays were significantly lower in the postconditioning group.

Conclusions: Adenosine postconditioning provided cardiac protection as evidenced by a favorable outcome on systolic and diastolic function indices, less cardiac troponin I and creatine kinase-MB release, lower incidence of arrhythmia, lower inotropic score, and shorter duration of postoperative mechanical ventilation and intensive care unit stay.

Keywords: adenosine; coronary artery bypass grafting; ischemia/reperfusion injury; postconditioning.