COMPARATIVE PROGNOSTIC-SIGNIFICANCE OF SIMULTANEOUS VERSUS INDEPENDENT RESOLUTION OF ST SEGMENT DEPRESSION RELATIVE TO ST SEGMENT ELEVATIONDURING ACUTE MYOCARDIAL-INFARCTION

Objectives. We sought to determine the prognostic significance of simu ltaneous versus independent resolution of ST segment depression that o ccurs concomitant with ST segment elevation during acute myocardial in farction (AMI). Background. ST segment depression in leads other than those showing ST segment elevation during AMI is a common phenomenon. Whether this indicates adverse outcomes remains controversial. We hypo thesized that the timing of ST segment depression resolution relative to ST segment elevation resolution might differentiate between a high risk group and a low risk group of patients. Methods. Continuous 12-le ad ST segment monitoring was performed after thrombolytic therapy for AMI in 413 patients, 261 of whom met technical criteria for analysis. Blinded analysis of ST segment depression resolution patterns was used to group patients as follows: 1) no ST segment depression at any time (control group); 2) ST segment depression resolving simultaneously wi th ST segment elevation (simultaneous group); and 3) ST segment depres sion persisting after ST segment elevation resolution (independent gro up). These patterns were correlated with the outcomes-recurrent angina , reinfarction, heart failure and death-using chi-square analysis and the Fisher exact test for categoric variables and the Wilcoxon rank-su m test for continuous variables. Results. The incidence of recurrent a ngina, reinfarction and heart failure was similar among the three grou ps. In hospital mortality, however, was significantly higher in the in dependent group (13%) than either the simultaneous group (1%, p < 0.00 1) or the control group (O%, p = 0.002). Conclusions. Continuous analy sis of ST segment resolution identifies, among patients with AMI with concomitantly occurring ST segment elevation and depression, a subgrou p with increased in hospital mortality. The pathogenic mechanism of in creased mortality is not currently known. (C) 1997 by the American Col lege of Cardiology.