EFFECTS OF PROPRANOLOL IN PATIENTS ENTERED IN THE BETA-BLOCKER HEART-ATTACK TRIAL WITH THEIR FIRST MYOCARDIAL-INFARCTION AND PERSISTENT ELECTROCARDIOGRAPHIC ST-SEGMENT DEPRESSION

Objective/Background If has been shown that patients with an acute myo cardial infarction and persistent electrocardiographic ST-segment depr ession are at high risk for subsequent cardiac events. The purpose of this retrospective analysis was to examine the long-term effects of pr opranolol therapy in patients with their first acute myocardial infarc tion and persistent electrocardiographic ST-segment depression. Method s The outcomes of 2877 patients enrolled in the Beta-Blocker Heart Att ack Trial (BHAT) with their first myocardial infarction (75% of patien ts in BHAT) were reviewed. Patients were divided into three groups on the basis of presence or absence of greater than or equal to 1 mm ST-s egment depression in two contiguous leads of the 12-lead electrocardio gram obtained soon after admission or at the time of randomization, wh ich occurred 10.1 +/- 3.5 days after the index myocardial infarction. Group 1 included 774 patients (392 randomly assigned to placebo and 38 2 to propranolol) with no ST-segment depression; group 2 included 1447 patients (713 placebo, 734 propranolol) with ST-segment depression at admission or at the time of randomization (labeled as transient); and group 3 included 656 patients (339 placebo and 317 propranolol) who h ad electrocardiographic ST-segment depression from the time of admissi on to the time of randomization (labeled as persistent). Results In gr oup 3, patients with persistent electrocardiographic ST depression, th e mortality rate in patients randomly assigned to placebo was 13.6% co mpared with 7.6% in patients with propranolol (p = 0.012; log rank tes t). Sudden death in the placebo arm was 9.7% compared with 4.7% in the propranolol group (p = 0.012, log rank test). The results of the Cox regression analysis, adjusting for all baseline variables with p value s <0.25, showed the relative risk of overall mortality rate and the re lative risk of sudden death were 2.13 (1.22, 3.70) and 2.56 (1.27, 5.2 6), respectively, for the placebo group compared with the propranolol group. Patients with persistent ST-segment depression had the greatest benefit from propranolol (47.2 fewer events [deaths/reinfarctions] pe r 1000 person-years compared with 7.8 and 2.1 fewer events in patients with transient and no ST-segment depression, respectively). Conclusio ns It appears that the greatest benefit for beta-blocker therapy in pa tients after myocardial infarction is observed in patients with persis tent ST-segment depression who are at greatest risk for death and rein farction. Definitive conclusions regarding therapy with beta-adrenergi c blocking agents in patients with persistent ST-segment depression ca nnot be made because our analysis, given its retrospective nature, is only hypothesis generating.