Efficacy of early invasive management post-fibrinolysis in men versus women with ST-elevation myocardial infarction: a subgroup analysis from Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI)

Abstract

Background: The TRANSFER-AMI study demonstrated that early routine percutaneous coronary intervention post-fibrinolysis (pharmacoinvasive strategy) is superior to conservative management for ST-elevation myocardial infarction. However, it is not clear whether treatment efficacy differs between men and women.

Methods: In this pre-specified subgroup analysis, we compared the efficacy of a pharmacoinvasive strategy in men versus women with acute ST-elevation myocardial infarction who were randomized to a pharmacoinvasive versus standard management following fibrinolysis. The primary end point was a composite of death, recurrent myocardial infarction, recurrent ischemia, heart failure and shock at 30 days. We tested for treatment heterogeneity between men and women using the Breslow-Day test. We also performed multivariable analysis adjusting for GRACE risk score and its interaction with treatment assignment, and evaluated for death/recurrent myocardial reinfarction as a secondary outcome.

Results: Of the 1059 patients, 843 were men and 216 were women. Compared to men, women were older, had worse Killip class, higher GRACE risk score, and higher rates of death and death/myocardial reinfarction at 30 days. The primary end point did not differ significantly between men and women (13.4% vs 16.7%, P = .22). Compared to standard treatment, a pharmacoinvasive strategy was associated with a lower rate of the primary end point in men (17.5% vs 9.4%, respectively, P < .001), but not in women (16.2% vs 17.1%, P = .86). There was a trend toward an interaction between treatment assignment and sex for the composite primary end point (P = .06). After adjustment for the significant interaction between GRACE risk score and treatment (P < .001), there was no significant interaction between sex and treatment for all the end points (all P > .40).

Conclusion: The borderline heterogeneity in treatment efficacy of a pharmacoinvasive strategy in men versus women was no longer evident after adjustment for the difference in baseline risk. This suggests that sex per se was not an important determinant of the efficacy of a pharmacoinvasive strategy. Owing to the small number of women in this trial, further study in this area is needed.

Trial registration: ClinicalTrials.gov NCT00164190.