Aspirin and clonidine in patients undergoing non-cardiac surgery

Aspirin and clonidine in patients undergoing non-cardiac surgery

 

POISE-2: PeriOperative ISchemic Evaluation-2 Trial

Using a 2-by-2 factorial trial design, 10,010 non-cardiac surgery patients at risk of perioperative cardiovascular events were randomised to low-dose aspirin or placebo, and low-dose clonidine or placebo. Aspirin and clonidine did not alter the incidence of death and major cardiovascular complications, but aspirin increased the risk of bleeding and clonidine increased the risk of hypotension. This led to more selective use of these agents in high-risk patients. This study was a collaboration with Population Health Research Institute (PHRI), McMaster University, Canada.

Principal investigator

Professor Kate Leslie AO FAHMS (Australian arm)

Recruitment

10,010 patients were enrolled between July 2010 and December 2013.

Participating countries

Australia, Canada and 21 other countries (135 centres)

Outcomes of the Clonidine trial

Methods
For the comparison of clonidine with placebo, patients were randomly assigned to receive clonidine (0.2 mg per day) or placebo just before surgery, with the study drug continued until 72 hours after surgery. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days.

Results
Clonidine, as compared with placebo, did not reduce the number of primary-outcome events (367 and 339, respectively; hazard ratio with clonidine, 1.08; 95% confidence interval [CI], 0.93 to 1.26; P=0.29). Myocardial infarction occurred in 329 patients (6.6%) assigned to clonidine and in 295 patients (5.9%) assigned to placebo (hazard ratio, 1.11; 95% CI, 0.95 to 1.30; P=0.18). Significantly more patients in the clonidine group than in the placebo group had clinically important hypotension (2385 patients [47.6%] vs. 1854 patients [37.1%]; hazard ratio 1.32; 95% CI, 1.24 to 1.40; P<0.001). Clonidine, as compared with placebo, was associated with an increased rate of nonfatal cardiac arrest (0.3% [16 patients] vs. 0.1% [5 patients]; hazard ratio, 3.20; 95% CI, 1.17 to 8.73; P=0.02). Conclusions: Administration of low-dose clonidine in patients undergoing noncardiac surgery did not reduce the rate of the composite outcome of death or nonfatal myocardial infarction; it did, however, increase the risk of clinically important hypotension and nonfatal cardiac arrest. 

Outcomes of the Aspirin trial

Methods
The patients were stratified according to whether they had not been taking aspirin before the study (initiation stratum, with 5628 patients) or they were already on an aspirin regimen (continuation stratum, with 4382 patients). Patients started taking aspirin (at a dose of 200 mg) or placebo just before surgery and continued it daily (at a dose of 100 mg) for 30 days in the initiation stratum and for 7 days in the continuation stratum, after which patients resumed their regular aspirin regimen. The primary outcome was a composite of death or nonfatal myocardial infarction at 30 days.

Results
The primary outcome occurred in 351 of 4998 patients (7.0%) in the aspirin group and in 355 of 5012 patients (7.1%) in the placebo group (hazard ratio in the aspirin group, 0.99; 95% confidence interval [CI], 0.86 to 1.15; P=0.92). Major bleeding was more common in the aspirin group than in the placebo group (230 patients [4.6%] vs. 188 patients [3.8%]; hazard ratio, 1.23; 95% CI, 1.01, to 1.49; P=0.04). The primary and secondary outcome results were similar in the two aspirin strata.

Conclusions
Administration of aspirin before surgery and throughout the early postsurgical period had no significant effect on the rate of a composite of death or nonfatal myocardial infarction but increased the risk of major bleeding.

Funding

The Australian National Health and Medical Research Council, Canadian Institutes of Health Research and others

Primary results publications

Clonidine trial
Devereaux PJ, Sessler DI, Leslie K, Kurz A, Mrkobrada M, Alonso-Coello P, Villar JC, Sigamani A, Biccard BM, Meyhoff CS, Parlow JL, Guyatt G, Robinson A, Garg AX, Rodseth RN, Botto F, Lurati Buse G, Xavier D, Chan MT, Tiboni M, Cook D, Kumar PA, Forget P, Malaga G, Fleischmann E, Amir M, Eikelboom J, Mizera R, Torres D, Wang CY, Vanhelder T, Paniagua P, Berwanger O, Srinathan S, Graham M, Pasin L, Le Manach Y, Gao P, Pogue J, Whitlock R, Lamy A, Kearon C, Chow C, Pettit S, Chrolavicius S, Yusuf S; POISE-2 Investigators.    Clonidine in patients undergoing noncardiac surgery. N Engl J Med. 2014 Apr 17;370(16):1504-13.

Aspirin trial
Devereaux PJ, Mrkobrada M, Sessler DI, Leslie K, Alonso-Coello P, Kurz A, Villar JC, Sigamani A, Biccard BM, Meyhoff CS, Parlow JL, Guyatt G, Robinson A, Garg AX, Rodseth RN, Botto F, Lurati Buse G, Xavier D, Chan MT, Tiboni M, Cook D, Kumar PA, Forget P, Malaga G, Fleischmann E, Amir M, Eikelboom J, Mizera R, Torres D, Wang CY, VanHelder T, Paniagua P, Berwanger O, Srinathan S, Graham M, Pasin L, Le Manach Y, Gao P, Pogue J, Whitlock R, Lamy A, Kearon C, Baigent C, Chow C, Pettit S, Chrolavicius S, Yusuf S; POISE-2 Investigators. Aspirin in patients undergoing noncardiac surgery. N Engl J Med. 2014 Apr 17;370(16):1494-503. doi: 10.1056/NEJMoa1401105. Epub 2014 Mar 31. PMID: 24679062.

Trial registration

ClinicalTrials.gov number, NCT01082874

Pubmed links

Last updated 12:23 18.11.2022