Body temperature in acute myocardial infarction and its relation to early intervention with metoprolol

In a subsample of 223 patients participating in a double-blind trial with metoprolol in suspected acute myocardial infarction, body temperature during the first 5 days in hospital was recorded. Patients developing infarction had a mean temperature of 37.3 degrees C compared with 36.8 degrees C for those with no infarction (P less than 0.001). A positive association was observed between enzyme-estimated infarct size and body temperature (P less than 0.001). Patients given metoprolol had a mean temperature of 37.0 degrees C as compared with 37.2 degrees C in those given placebo (P = 0.03). The most marked difference between metoprolol and placebo was observed among those treated very early. We conclude that early treatment with metoprolol in suspected acute myocardial infarction appears to lower body temperature during the following days. This might reflect limitation of the infarct size.