Extent of ST-segment deviation in a single electrocardiogram lead 90 min after thrombolysis as a predictor of medium-term mortality in acute myocardial infarction

Background In evolving myocardial infarction, assessment of the sum of earl y resolution of ST-segment elevation (sumSTR) has become an established met hod to predict outcome. We have found previously that mortality is predicte d more accurately by the existing ST-segment deviation in the single electr ocardiograph (ECG) lead with maximum deviation (maxSTE) 90 min after start of thrombolysis. This report compares the power to predict medium-term mort ality by these two approaches. Methods An ST-segment resolution substudy was done in conjunction with the Intravenous nPA for Treatment of Infarcting Myocardium Early (InTIME) II St udy, which compared mortality in patients with acute myocardial infarction randomly assigned lanoteplase or alteplase. In 2719 patients, a 12-lead ECG was assessed at baseline and 90 min after the start of thrombolytic therap y. Findings MaxSTE achieved a better combination of sensitivities and specific ities for mortality prediction than sumSTR. The area under the receiver-ope rating characteristic curves for 180-day mortality prediction was 0.680 for maxSTE and 0.622 for sumSTR (difference 0.058; 95% CI 0.027-0.088). Risk g roups categorised at low, medium, or high risk by maxSTE comprised 43%, 32% , and 24% of patients and those by complete, partial, or no sumSTR comprise d 40%, 36%, and 24% of all patients. The 180-day mortality rates for the th ree maxSTE risk groups were 3.1%, 7.1%, and 16.2%, and those for the sumSTR groups were 4.8%, 8.1%, and 11.7%. The 12-month Kaplan-Meier estimates wer e 4.1%, 8.8%, and 18.6%, and 5.9%, 9.9%, and 13.7%, respectively. Interpretation MaxSTE predicts early and medium-term mortality more accurat ely than does sumSTR. The prognosis for an individual patient can be accura tely estimated simply by the ST-segment deviation present in one ECG lead r ecorded 90 min after thrombolysis.