PROGNOSTIC-SIGNIFICANCE OF ST SEGMENT SHIFT EARLY AFTER RESOLUTION OFST ELEVATION IN PATIENTS WITH MYOCARDIAL-INFARCTION TREATED WITH THROMBOLYTIC THERAPY - THE GUSTO-I ST SEGMENT MONITORING SUBSTUDY

Objectives. We sought to study the relation between recurrent ST segme nt shift within 6 to 24 h of initial resolution of ST elevation after thrombolytic therapy and 30-day and 1-year mortality. Background. Rapi d and stable resolution of ST segment elevation in relation to thrombo lytic therapy in patients with an acute myocardial infarction is an in dicator of culprit artery patency. Whether recurrence of ST segment sh ift during continuous ST monitoring after initial resolution is relate d to poor prognosis has not been studied. Methods. ST segment monitori ng was performed within 30 min after thrombolytic therapy for acute my ocardial infarction. The predictive value of a new ST segment shift (a ssessed as greater than or equal to 0.1-mV deviation from the baseline ) 6 to 24 h after thrombolytic therapy was studied with respect to 30- day and 1-year mortality. Results. Of 734 patients, 243 had a new ST s egment shift (33%). The 30-day mortality rate in patients with an ST s hift (7.8%) was significantly higher than that in patients without an ST shift (2.25%, p = 0.001), as was the 1-year mortality rate (10.3% v s. 5.7%, respectively, p = 0.025). Multivariable analysis revealed an independent predictive value of ST shift with respect to 30-day mortal ity (p = 0.008), even after consideration of multiple clinical risk fa ctors in the overall Global Utilization of Streptokinase and TPA for O ccluded Coronary Arteries (GUSTO)-I mortality model (p = 0.0001). More over, the duration of the ST shift bore a direct relation with 1-year mortality (p = 0.008). Conclusions. Detection of ST segment shift earl y after thrombolytic therapy for acute myocardial infarction is a simp le, noninvasive means of identifying patients at high risk and is supe rior to other commonly assessed clinical risk factors. Thus, patients with a new ST shift after the first 6 h, but within 24 h, represent a high risk group that may benefit from more aggressive intervention, wh ereas patients without evidence of an ST shift represent a low risk su bgroup. (C) 1998 by the American College of Cardiology.