Background: Non-steroidal anti-inflammatory drugs (NSAIDs) may be prothrombotic, may worsen hypertension or congestive heart failure and obstruct access to the binding site of aspirin to cyclooxygenase-1 and thereby interfere with aspirin's mechanism of action in reducing death and recurrent myocardial infarction (MI). We hypothesized that treatment with NSAIDs prior to an index MI would be associated with an increase in the risk of death, heart failure and recurrent MI among patients with ST-segment elevation MI (STEMI) treated with fibrinolytic therapy.
Methods: In ExTRACT-TIMI 25, patients with STEMI were treated with aspirin and fibrinolytic therapy and randomized to either enoxaparin or unfractionated heparin. We included patients who had received NSAIDs within 7 days of enrollment and evaluated the incidence of MI, the composite of death and MI and the composite of death, MI, severe heart failure and shock through 30 days.
Results: Of 20,479 patients enrolled, 572 (2.8%) received an NSAID within 7 days of enrollment. NSAID treatment prior to entry was associated with a higher incidence of 30-day death or nonfatal recurrent MI (15.9% vs. 10.8%, univariate P < 0.001). In multivariable models adjusting for randomization group and differences in baseline characteristics, NSAID use was associated with higher odds of MI (adjusted odds ratio [OR(adj)] 1.44, 95% confidence interval [CI] 1.01-2.07, P = 0.047), the composite of death and MI (OR(adj) 1.29, 95% CI 1.00-1.66, P = 0.051), and the composite of death, MI, severe heart failure and shock (OR(adj) 1.29, 95% CI 1.02-1.65, P = 0.037).
Conclusions: Among STEMI patients treated with a fibrinolytic agent and aspirin, use of NSAIDs in the week preceding the incident event was associated with a higher incidence of MI, the composite of death and MI as well as the composite of death, MI, severe heart failure and shock at 30 days.