Comparison of left ventricular ejection fraction and inducible ventricular tachycardia in ST-elevation myocardial infarction treated by primary angioplasty versus thrombolysis

Electrophysiologic studies predict the risk for sudden death after myocardial infarction (MI). Although primary angioplasty has become the preferred method of treatment for ST-elevation MI, intravenous thrombolysis remains the first-line treatment in 30% to 70% of cases worldwide. Rates of ventricular tachyarrhythmias may vary according to type of reperfusion treatment. This study was undertaken to examine the hypothesis that the left ventricular ejection fraction (LVEF) and rates of inducible ventricular tachycardia may be more favorable in treatment with primary angioplasty rather than thrombolysis. Consecutive patients receiving primary angioplasty (n = 225) or thrombolysis (n = 195) for ST-elevation MI were included. The mean LVEF was 48 +/- 12% for the primary angioplasty group and 46 +/- 13% for the thrombolysis group (p = 0.30). The proportion of patients with LVEFs <40% was 30% in the primary angioplasty group and 30% in the thrombolysis group (p = 0.98). Patients with LVEFs <40% underwent electrophysiologic studies. Ventricular tachycardia was inducible in 23 of 66 primary angioplasty patients (34.8%) compared with 21 of 55 (38.1%) thrombolysis patients (p = 0.69). Implantable cardiac defibrillators were inserted in 30 patients, of whom 8 (27%) had appropriate device activations. The mean time from MI to first spontaneous activation was 387 +/- 458 days. In conclusion, patients treated with thrombolysis or primary angioplasty for ST-elevation MIs had similar resultant LVEFs and rates of inducible ventricular tachycardia. There was a surprisingly high rate of spontaneous defibrillator activations, often occurring late after MI. (C) 2008 Elsevier Inc. All rights reserved.