Abstract 2652: Primary Angioplasty And Thrombolysis For ST Elevation Myocardial Infarction Result In Similar Left Ventricular Function And Rates Of Inducible Ventricular Tachycardia.
Introduction/Hypothesis. Electrophysiological studies (EPS) predict risk of sudden death after myocardial infarction. Primary angioplasty has become the preferred method of treatment for STEMI due to improved patency rates of the infarct related artery, along with decreased rates of reinfarction and death. Despite this, intravenous thrombolysis remains the first line treatment in 30 –70% of cases worldwide. We assessed the hypothesis that the left ventricular ejection fraction (LVEF) and rates of inducible VT would be more favorable in patients treated with primary angioplasty compared to thrombolysis.
Methods/Results. Consecutive patients receiving primary angioplasty (n=225) or thrombolysis (n=195) for STEMI were included. Mean LVEF assessed predominantly by gated blood heart pool scan was 47.7 ±12.1% for the primary angioplasty group and 46.3 ±13.0% for the thrombolysis group (p=0.30). The proportion of patients with LVEF less than 40% was 29.7% in the primary angioplasty group and 29.6% in the thrombolysis group (p=0.98). Patients with LVEF less than 40% underwent EPS. VT was inducible in 10% of patients who had primary angioplasty versus 11% of patients who had thrombolysis (p=0.69). Mean cycle length (CL) of inducible VT in milliseconds (ms) was 246 ± 48 for the angioplasty group and 261 ± 62 for thrombolysis group (p=0.65). Implantable cardiac defibrillators were inserted in 30 patients of which 8 (27%) had appropriate device activations. The mean time from infarction to first spontaneous activation was 387 ± 458 days. Mean CL of spontaneous VT was 314 ± 62 ms.
Conclusions. In conclusion patients treated with thrombolysis or primary angioplasty for STEMI are likely to have similar resultant left ventricular function and rates of inducible ventricular tachycardia. There was a surprisingly high rate of spontaneous defibrillator activations often occurring late after myocardial infarction.