[Primary dilatation versus thrombolysis in patients with acute myocardial infarct, not included in randomized studies. Results of the MITRA Study. Maximal Individual Optimized Therapy for Acute Myocardial Infarct].

There have been some prospective randomized studies which compared primary angioplasty with intravenous thrombolysis in patients with an acute myocardial infarction (AMI). However, a substantial number of patients with AMI who would not have been included in those trials are treated with one of these two therapeutic options. To describe the proportions, characteristics, and outcome of these patients treated with primary angioplasty or thrombolysis we analyzed the data of the prospective "Maximal Individual Optimized Therapy for Acute Myocardial Infarction" (MITRA) trial. Out of 3308 patients treated with primary angioplasty or thrombolysis, 737 (22.3%) belonged to one of the following groups, not included in current randomized trials: Left bundle branch block, non-diagnostic first ECG, pre-hospital delay > 12 hours or unknown pre-hospital delay. Primary angioplasty was performed in 158/737 (21.4%) and thrombolysis received 579/737 (78.6%) of the patients. There were only minor differences regarding patients' characteristics and concomitant diseases between the two groups. Patients treated with primary angioplasty were 3 years younger (62 years median versus 65 years median (p < 0.036). They also more often showed overt heart failure at admission compared to patients treated with thrombolysis (primary angioplasty: 3.2% versus thrombolysis: 8.9%, OR = 0.34, 95% CI: 0.13-0.86). In-hospital time to intervention was 1 1/2 hours longer in patients treated with primary angioplasty (156 minutes median versus 47 minutes median, p = 0.001). beta-blockers were more often used with primary angioplasty compared to thrombolysis (70.31% versus 55.9%; OR = 1.87, 95% CI: 1.28-2.72), as well as ACE inhibitors (62% versus 49.9%; OR = 1.64, 95% CI: 1.14-2.35). Hospital mortality (8.2% versus 16.4%; OR = 0.46, 95% CI: 0.25-0.84), as well as a combined endpoint of death, reinfarction, postinfarction angina, advanced heart failure, and stroke (24.1% versus 42.3%, OR = 0.43, 95% CI: 0.29-0.64) were lower in patients treated with primary angioplasty compared to those treated with thrombolysis. Logistic regression analysis showed primary angioplasty to be independently associated with a lower rate of the combined endpoint (OR = 0.73, 95% CI: 0.59-0.91), after adjusting for confounding parameters. All subgroups showed a more favorable outcome in patients treated with primary angioplasty. In clinical practice, patients with AMI, not included in current randomized trials comparing primary angioplasty with thrombolysis, account for 22% of all patients with AMI treated with one of those two therapies. Primary angioplasty seems to be associated with a lower event rate compared to thrombolysis in these patients. This has to be confirmed by a prospective randomized trial.