Coronary artery disease
Clinical Benefit of Early Reperfusion Therapy in Patients With ST-Elevation Myocardial Infarction Usually Excluded from Randomized Clinical Trials (Results from the Maximal Individual Therapy in Acute Myocardial Infarction Plus [MITRA Plus] Registry)

https://doi.org/10.1016/j.amjcard.2009.05.054Get rights and content

Randomized clinical trials (RCTs) usually enroll selected patient populations that may not be representative for patients seen in everyday practice. Therefore, concerns have been raised regarding their external validity. For the present study we evaluated the MITRA Plus registry and included 20,175 patients with ST-elevation myocardial infarction. We defined RCT-ineligible patients as patients fulfilling ≥1 of the following criteria: age ≥75 years, prehospital delay >12 hours, prehospital cardiopulmonary resuscitation, cardiogenic shock, impaired renal function, and previous stroke. Those patients (n = 9,369, 46.4%) were compared to patients eligible for enrollment in RCTs (n = 11,806, 53.6%). Ineligible patients were older (p <0.0001), more often were women (p <0.0001), and more often had concomitant diseases (p <0.0001). Ineligible patients less often received early reperfusion therapy (p <0.0001), aspirin (p <0.0001), clopidogrel (p <0.0001), and statins (p <0.0001). Ineligible patients had a higher hospital mortality (20.1% vs 4.9%; p <0.0001) and a higher rate of nonfatal strokes (1.5% vs 0.4%, p <0.0001) compared to eligible patients. Early reperfusion therapy (thrombolysis and/or percutaneous coronary intervention [PCI]) in ineligible patients was associated with a significant decrease of hospital mortality (odds ratio 0.62, 95% confidence interval 0.49 to 0.79), with primary PCI being more effective than thrombolytic therapy (odds ratio 0.52, 95% confidence interval 0.41 to 0.65). In conclusion, about 50% of patients with ST-elevation myocardial infarction seen in clinical practice are usually excluded from RCTs. Hospital mortality in those patients is very high. Primary PCI improves the prognosis and is therefore the preferred reperfusion strategy in these patients.

Section snippets

Methods

The Maximal Individual Therapy in Acute Myocardial Infarction Plus (MITRA Plus) registry is a German, prospective, multicenter, observational data pool of current treatment of acute MI. From 1992 to 2002, 21,175 consecutive patients were included in the MITRA Plus registry. The MITRA Plus registry consists of 4 consecutive subregistries that have been previously described: the 60 Minutes Myocardial Infarction Project (60-minute MIP),1 Maximal Individual Therapy in Acute Myocardial Infarction

Results

For the present study we evaluated the MITRA Plus registry and included 11,806 patients with STEMI eligible for enrollment in RCTs and 9,369 patients with STEMI usually excluded from RCTs. In total 53.5% of ineligible patients were >75 years old, 3.3% had a previous stroke, 13.1% prehospital cardiopulmonary resuscitation, 5.5% impaired renal function, 40.7% prehospital delay >12 hours, and in 11.0% STEMI was complicated by cardiogenic shock. Baseline characteristics and acute adjunctive

Discussion

Patients with STEMI included in RCTs represent a selected subgroup of patients with a low adverse event rate. This subgroup may therefore not be representative of patients encountered in everyday practice. About 50% of patients seen in clinical practice are usually excluded from RCTs. In the present study ineligible patients more often had concomitant diseases compared to eligible patients. In addition, ineligible patients less often received early reperfusion therapy and adjunctive

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