Context: There are no definitive recommendations for the management of acute myocardial infarction (AMI) in patients with ST-segment elevation who have contraindications to thrombolytic therapy. It is not clear whether, and the extent to which, immediate mechanical reperfusion (IMR) reduces in-hospital mortality in this population.
Objective: To determine whether IMR (defined as percutaneous coronary intervention or coronary artery bypass graft surgery) is associated with a mortality benefit in patients with acute ST-segment elevation AMI who are eligible for IMR but have contraindications to thrombolytic therapy.
Design, setting, and patients: From June 1994 to January 2003, the National Registry of Myocardial Infarction 2, 3, and 4 enrolled 1 799 704 patients with AMI. A total of 19 917 patients with acute ST-segment elevation were eligible for IMR but had thrombolytic contraindications after excluding patients who were transferred in from or out to other facilities, patients who received intracoronary thrombolytics, and those who received no medications within 24 hours of arrival.
Main outcome measure: In-hospital mortality.
Results: Of the 19 917 patients, 4705 patients (23.6%) received IMR and 5173 patients (25.9%) died. In-hospital mortality rates in the IMR and non-IMR treated groups in the unadjusted analysis were 11.1%, representing 521 of 4705 patients, and 30.6%, representing 4652 of 15 212 patients, respectively, for a risk reduction of 63.7% (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.26-0.31). In a further analysis using a propensity matching score to reduce the effects of bias, 3905 patients who received IMR remained at lower risk for in-hospital mortality than 3905 matched patients (10.9% vs 20.1%, respectively, for a risk reduction of 45.8%; OR, 0.48; 95% CI, 0.43-0.55). Following a second logistic model applied to the matched groups to adjust for residual differences, a significant treatment effect persisted (OR, 0.64; 95% CI, 0.56-0.75).
Conclusions: In this population, IMR was associated with a reduced risk of in-hospital mortality after appropriate adjustments. Of those we studied who were eligible for IMR, 15 212 patients (76.4%) did not receive it. These results suggest that using IMR in patients with acute ST-segment elevation AMI and contraindications to thrombolytics should be strongly considered.