The effect of beta-blocker dosing strategy on regulation of perioperative heart rate and clinical outcomes in patients undergoing vascular surgery: a randomized comparison.

The optimal dosing strategy for perioperative beta-blockers to safely achieve recommended target heart rates (HRs) by current guidelines is not well defined. An HR-titrated perioperative beta-blocker dosing regimen versus a fixed-dose regimen was assessed by clinical outcomes, postoperative heart rate, and beta-blocker-related complications. Patients (n = 64) scheduled to undergo moderate- to high-risk vascular surgery and without contraindications to beta-blockade were randomized to either a fixed-dose or HR-titrated beta-blocker dosing schedule. Clinical outcomes and HRs were followed immediately preoperatively to 24 hr postoperatively. A difference in mean HR between the two dosing arms was significant immediately postoperatively (70.1 vs. 58.2 bpm for fixed dose and HR-titrated arms, respectively; p = 0.012) but at no other time points. However, the HR-titrated strategy led to a significant reduction in the percentage of HR measurements >80 bpm (34.5% vs. 16.1%, p < 0.001) and to a significant reduction in absolute HR change (17.5 vs. 22.5 bpm, p = 0.034). There were no significant differences in the occurrence of asymptomatic hypotension between the two study arms, and no beta-blocker-related adverse events occurred in either study arm. An aggressive, HR-titrated perioperative beta-blocker dosing strategy was associated with more consistent maintenance of postoperative HRs within the range recommended by current guidelines and did not result in increased drug-related adverse events. The question of what is the best perioperative beta-blocker dosing regimen warrants further evaluation in a large-scale clinical trial.