Micro- and Macrocirculatory Effects of Landiolol: A Double-Blind, Randomized Study Following Cardiac Surgery

Abstract Background: Postoperative atrial fibrillation (POAF) increases morbidity and mortality after cardiac surgery. Landiolol, a selective ultra-short-acting betablocker has been recently suggested to prevent POAF in the cardiac surgical setting with a good safety profile. Micro- and detailed macrocirculatory effects of landiolol remain however largely unknown in that setting.Methods: We conducted a prospective, randomized, double-blind study versus placebo in patients undergoing conventional cardiac surgery. Incremental doses of intravenous landiolol from 0.5 to 10 μg-1.kg-1.min-1 or placebo were administrated postoperatively. Microcirculatory variables were assessed by both peripheral near-infrared spectroscopy (NIRS) in combination with a vascular occlusion test and sublingual videomicroscopy. Macrocirculatory variables were obtained from transpulmonary thermodilution and transthoracic echocardiography. Results: Fifty-nine adult patients were allocated to the landiolol group (n=30) or the placebo group (n=29) from January to November 2019. Heart rate significantly decreased in the landiolol group (P<0.01) whereas mean arterial pressure (P=0.05) and stroke volume (P=0.63) were not significantly modified throughout the study. No modification was found in left and right systolic and diastolic ventricular functions except a significant increase in E/A ratio in the landiolol group (P=0.02). No difference was evidenced between groups in microcirculatory parameters at any landiolol dose. POAF occurred in 9 (32%) vs. 5 (17%) patients in placebo and landiolol groups, respectively (P=0.28). Conclusions: Postoperative incremental doses of landiolol up to 10 μg-1.kg-1.min-1 are efficacious to control heart rate without significant alterations in both micro- and macrocirculation following conventional cardiac surgery.