Prevention of Perioperative Cardiac Events Using Clonidine in Patients with Coronary Artery Disease Undergoing Noncardiac Surgery: A Meta-Analysis

Abstract

Background: Clonidine may help prevent cardiac events in patients with coronary artery disease (CAD) undergoing noncardiac surgery by sympatholysis. This study aims to provide a systematic review of randomized controlled trials (RCTs) that assessed the efficacy of low-dose clonidine in preventing cardiac events perioperatively. Methods: The authors independently searched the online sites of Medline, PubMed and the Cochrane Database of Systematic Reviews for RCTs involving human participants. The search terms clonidine, prevention, myocardial ischemia, myocardial infarction, and noncardiac surgery were used. Results: Five trials comprising 10,618 participants were analyzed for the efficacy of low-dose clonidine in preventing cardiac events among patients with CAD undergoing noncardiac surgery. Low dose clonidine significantly reduced the incidence of myocardial ischemia in patients undergoing noncardiac surgery (RR 0.64; 95% CI, 0.50, 0.81), but it was not associated with any significant reduction in the risk of myocardial infarction (RR 1.09; 95% CI, 0.94, 1.27), congestive heart failure (RR 1.24; 0.83, 1.85), cardiac arrhythmia (RR 1.10; 95% CI, 0.84, 1.45), and death (RR 0.93; 95 % CI, 0.67, 1.29). Significantly more patients in the clonidine group had hypotension compared to placebo (RR 1.28; 95 % CI, 1.22, 1.34). Conclusion: The meta-analysis suggests that perioperative low-dose clonidine reduced myocardial ischemia in patients at risk of CAD. However, it increased the risk of hypotension. The trend in reduction of mortality using low-dose clonidine was not statistically significant. The use of low-dose clonidine did not affect the risk of perioperative myocardial infarction, congestive heart failure and cardiac arrhythmia.