Single lead ST-segment recovery: A simple, reliable measure of successful fibrinolysis after acute myocardial infarction Mushabbar A. Syed, MD, a Steven Borzak, MD, b Abed Asfour, MD, a Madhavi Gunda, MD, a Omar Obeidat, MD, a Sabina A. Murphy, MPH, c Raymond J. Gibbons, MD, d Steven G. Gourlay, MBBS, PhD, e Hal V. Barron, MD, e W. Douglas Weaver, MD, a and Michael Hudson, MD, MHS a Detroit, Mich, Atlantis, Fla, Boston, Mass, Rochester, Minn, and San Francisco, Calif Background Successful reperfusion after acute ST-elevation myocardial infarction improves prognosis. Among the different electrocardiographic markers of reperfusion, sum ST resolution is considered the hallmark of reperfusion, but is cumbersome to use. Methods To assess the usefulness of a single lead ST resolution at 90 minutes after fibrinolysis compared with the sum ST resolution in predicting Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow, we used prospectively collected data from the Limitation of Myocardial Injury Following Thrombolysis in Acute Myocardial Infarction (LIMIT-AMI) study. All patients had electrocardiograms recorded at presentation and 90 minutes and a coronary angiogram 90 minutes after fibrinolysis. Results Infarction artery patency was assessed in 238 patients with 4 different ST resolution criteria: single lead ST resolution 50% and 70% and sum ST resolution 50% and 70%. The most sensitive criteria for TIMI grade 3 flow was single lead ST resolution 50% (sensitivity rate, 70%; specificity rate, 54%), whereas sum ST resolution 70% was most the specific criteria (sensitivity rate, 45%; specificity rate, 79%). The proportion of patients with TIMI grade 3 flow was similar in all 4 ST resolution groups (P = .84). Pre-discharge infarction size and ejection fraction were also similar. No single lead or sum lead measure of ST resolution was significantly associated with an increased risk of death, heart failure, or reinfarction. Conclusion We propose that single lead ST-resolution 50% as an optimal electrocardiographic indicator for suc- cessful reperfusion 90 minutes after fibrinolysis. This simple electrocardiographic measure should be combined with bed- side clinical and hemodynamic assessment to optimize decision making after fibrinolysis. (Am Heart J 2004;147: 275– 80.) Achieving optimal Thrombolysis in Myocardial Infarc- tion (TIMI) grade 3 coronary blood flow after fibrinoly- sis preserves left ventricular function and improves survival in patients with ST-elevation acute myocardial infarction (MI). 1 In patients receiving fibrinolytic agents, accurate assessment of reperfusion success and infarction artery patency is useful prognostically and may identify patients at high risk who are likely to benefit from rescue percutaneous coronary interven- tion (PCI). 2,3 To appropriately identify suitable candi- dates for rescue PCI, several noninvasive bedside mea- sures have been studied, including chest pain resolution, cardiac biomarkers, and different electro- cardiographic (ECG) changes. 4–8 Among the different ECG indicators of reperfusion, ST segment resolution has been most studied and is currently considered the hallmark of successful reperfusion and prognosis. 9 –12 Different ST resolution criteria with continuous or serial ECG monitoring at multiple points after fibrinoly- sis have been proposed to assess reperfusion success. Schro ¨der et al 13 compared different degrees of ST reso- lution and found 70% resolution at 180 minutes after fibrinolysis to be an optimal predictor of outcome after acute MI. In the ECG ischemia monitoring substudy of From the a Henry Ford Heart and Vascular Institute, Detroit, Mich, b Florida Cardiovas- cular Research, LC, Atlantis, Fla, c TIMI Study Group, Brigham and Women’s Hospital, Boston, Mass, d Mayo Clinic, Rochester, Minn, and e Genentech, South San Francisco, Calif. Supported by Genentech Inc. Drs Gourlay and Barron are employees of Genentech Inc. Submitted May 14, 2003; accepted August 25, 2003. Reprint requests: Michael Hudson, MD, MHS, FACC, Henry Ford Heart and Vascular Institute, (K-14), 2799 West Grand Blvd. Detroit, MI 48202. E-mail: mhudson1@hfhs.org 0002-8703/$ - see front matter © 2004, Elsevier Inc. All rights reserved. doi:10.1016/j.ahj.2003.08.010