To assess whether the administration of the ultra-short–acting β-blocker esmolol in cardiac surgery could have a cardioprotective effect that translates into improved postoperative outcomes.

Single-center, double-blinded, parallel-group randomized controlled trial.

A tertiary care referral center.

Patients undergoing elective cardiac surgery with preoperative evidence of left ventricular end-diastolic diameter >60 mm and/or left ventricular ejection fraction <50%.

Patients were assigned randomly to receive either esmolol (1 mg/kg as a bolus before aortic cross-clamping and 2 mg/kg mixed in the cardioplegia solution) or placebo in a 1:1 allocation ratio.

The primary composite endpoint of prolonged intensive care unit stay and/or in-hospital mortality occurred in 36/98 patients (36%) in the placebo group versus 27/102 patients (27%) in the esmolol group (p = 0.13). In the esmolol group, a reduction in the maximum inotropic score during the first 24 postoperative hours was observed (10 [interquartile range 5-15] v 7 [interquartile range 5-10.5]; p = 0.04), as well as a trend toward a reduction in postoperative low-cardiac-output syndrome (13/98 v 6/102; p = 0.08) and the rate of hospital admission at one year (26/95 v 16/96; p = 0.08). A trend toward an increase in the number of patients with ejection fraction ≥60% at hospital discharge also was observed (4/95 v 11/92; p = 0.06).

In the present trial, esmolol as a cardioplegia adjuvant enhanced postoperative cardiac performance but did not reduce a composite endpoint of prolonged intensive care unit stay and/or mortality.