Prognostic value of prolonged ventricular repolarization following myocardial infarction: The BHAT experience

In the Beta Blocker Heart Attack Trial (BHAT), 3837 patients were randomized to propranolol (180-240 mg/day) or placebo 5-21 days after a documented myocardial infarction and were followed in a double blind manner for a mean period of 25 months. Twelve lead electrocardiograms were routinely obtained at the time of randomization (baseline electrocardiogram) and at 12 and 24 months of follow-up. There was a positive correlation between baseline QTc interval prolongation (but not QT prolongation) and mortality and sudden death that was independent of treatment group. The data for non-sudden death and non-fatal reinfarction exhibit similar trends. We conclude that: (1) QTc prolongation identifies a high risk subset of post myocardial infarction patients. (2) The relative benefit of propranolol is similar in patients with normal and prolonged QTc.