PJ Devereaux, Population Health Research Institute, Hamilton, Canada

on behalf of POISE-2 Investigators

PeriOperative ISchemic Evaluation-2 Trial

POISE-2POISE-2POISE-2POISE-2

Aspirin in Patients Undergoing Noncardiac Surgery

Background

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• Worldwide 200 million adults have noncardiac surgery annually • 10 million suffer major vascular complication

• MI is most common• Surgery – associated with platelet activation

• thrombosis may be mechanism of periop MI• Substantial variability in periop usage of aspirin

• aspirin-naive pts and pts taking aspirin chronically

Methods

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• Design – blinded RCT, 135 centres in 23 countries • Eligibility criteria –undergoing noncardiac surgery,

≥45 yrs, at risk of vascular complication• Recruitment –10,010 pts, July 2010 to Dec 2013 • 2 aspirin strata - Starting Stratum (n=5628),

Continuation Stratum (n=4382)• Intervention - aspirin/placebo (200 mg) just

before surgery; continued daily (100 mg) 30 days in Starting and 7 days in Continuation Stratum

• Primary outcome: composite of death and nonfatal MI at 30 days

Results

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Outcome Aspirin(4998)

Placebo(5012)

HR (95% CI)

P

1O outcome:death or MI 351 (7.0) 355 (7.1)

0.99 (0.86-1.15) 0.92

2O outcome:death, MI, or strokedeath, MI, revasc, or VTE

362 (7.2)

402 (8.0)

370 (7.4)

407 (8.1)

0.98 (0.85-1.13)

0.99 (0.86-1.14)

0.80

0.90

3O outcomes:MI 309 (6.2) 315 (6.3) 0.98 (0.84-1.15) 0.85

safety outcomeMajor bleeding 229 (4.6) 187 (3.7) 1.23 (1.01-1.49) 0.04

Results• Primary and 2nd outcome results similar in both

aspirin strata• 65% of patients received prophylactic anticoag• Multivariable regression – life-threatening or

major bleed independent predictor of periop MI– HR, 1.82; (95% CI, 1.40-2.36); P<0.001

• Post-hoc analyses suggest– 1.0-1.3% absolute increase in life-threatening or

major bleeding if aspirin started within 2 days after Sx• risk decreases to 0.3% if started on day 8 after surgery 5

Conclusions

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• Perioperative aspirin did not prevent • death or MI but increased risk of major bleeding

• Primary and 2nd outcome results consistent • both aspirin strata

• Life-threatening and major bleeding • independent predictor of MI

• Optimal time to restart aspirin • 8 – 10 days after surgery