Milrinone improves diastolic function in coronary artery bypass surgery as assessed by acoustic quantification and peak filling rate: a prospective randomized study.

Objective: To compare the effects of a bolus dose of milrinone, 50 microg/kg, to placebo on diastolic function (active relaxation) in patients undergoing on-pump coronary artery bypass grafting (CABG).

Design: Prospective, randomized, double-blind, placebo-controlled study.

Setting: University hospital.

Participants: Twenty-four patients with stable angina and left ventricular ejection fraction >30%, scheduled for elective CABG using cardiopulmonary bypass (CPB), were included.

Intervention: Patients were randomized to receive either 50 microg/kg of milrinone (n = 12) or placebo (n = 12) after aortic declamping.

Measurements And Main Results: The diastolic function of the left ventricle (LV) was measured as peak filling rate (dA/dt [maximal diastolic area change over time]) with transesophageal echocardiography (TEE) using acoustic quantification (AQ) before CPB and 10 minutes after termination of CPB. The normalized peak filling rate (dA/dt)/EDA was also calculated. Active relaxation was statistically significantly increased in the milrinone group compared with the placebo group after CPB.

Conclusion: Patients undergoing CABG surgery and treated with milrinone after aortic declamping had better diastolic function following cardiopulmonary bypass.