Levosimendan Increases Bleeding Risk After Heart Valve Surgery: A Retrospective Analysis of a Randomized Trial

Objective To investigate whether levosimendan, an inotrope with cardioprotective properties, increases postoperative bleeding after cardiac surgery. Design Retrospective analysis of a randomized, prospective clinical study. Setting Post-anesthesia care unit (PACU) and surgical ward in a university hospital. Participants Two hundred heart valve surgery patients. Interventions The patients were randomized to receive either a 24-hour intravenous infusion of levosimendan or placebo. Infusion was administered as a 24 µg/kg bolus over 30 minutes and then continued at a dose of 0.2 µg/kg/min. Measurements and Main Results Postoperative bleeding was approximately 31% greater in the levosimendan group (1050 mL) compared to the placebo group (880 mL, p = 0.008). Serious bleeding exceeding 1000 mL was more common in the levosimendan group than the placebo group (51 v 38 patients, p = 0.044, risk ratio (RR) 1.37, 95% CI 1.00-1.87). However, the risk of reoperation for bleeding did not increase if patients received levosimendan (RR 1.52, 95% CI 0.77-2.97, p = 0.309). This result did not change after excluding patients who received clopidogrel preoperatively (RR 2.13, 95% CI 0.98-4.65, p = 0.145). The groups did not differ regarding transfused blood products. Eight patients, including seven from the levosimendan group, had delayed (diagnosed>48 hours after the surgery) cardiac tamponade and underwent re-exploration (7 v 1, p = 0.031). Conclusions Levosimendan increased the risk of postoperative bleeding after cardiac valve surgery. In addition, the risk of postoperative cardiac tamponade was increased in patients who received levosimendan compared to placebo.