Characteristics and clinical outcome of 458 patients with acute myocardial infarction requiring mechanical ventilation. Results of the BEAT registry of the ALKK-study group.

Background: Information about the clinical course of patients with acute myocardial infarction requiring mechanical ventilation is scarce. We sought to evaluate the clinical outcome of a large cohort of such patients in clinical practice.

Methods: The German BEAT registry prospectively enrolled consecutive patients requiring mechanical ventilation who were admitted to an internal intensive care unit (ICU) of 45 participating German hospitals between September 2001 and June 2002. For this analysis, we created a subgroup of patients with acute ST-segment-elevation or non-ST-segment-elevation myocardial infarction.

Results: During the 9-month study period, 458 consecutive patients fulfilled our inclusion criteria. The mean age was 68 ± 8 years and 71% were men. 40% of the patients were already intubated in the prehospital phase. The initial reason for intubation was in 48% of the cases ventricular fibrillation/tachycardia or sudden cardiac death, in 39% congestive heart failure and in 13% of the cases non-cardiac. The median time of ventilation was 2 days (1-5) among survivors and 1 day (0-5) among non-survivors. Of the 458 patients, 256 (56%) had already or developed cardiogenic shock, 86 (19%) acute renal failure, 76 (17%) coma or brain damage, 64 (14%) severe infection, 46 (10%) sepsis and 28 (6%) multiorgan distress syndrome; 11% were treated with fibrinolysis, 39% with PCI and 6% with coronary artery bypass grafting. The overall hospital mortality rate was 48%. In patients with cardiogenic shock, mortality was even higher with 69%.

Conclusions: Patients requiring mechanical ventilation during an acute myocardial infarction constitute a high risk group with a mortality of about 50%. Further research is necessary to improve the outcome of these patients.