Relation of Early Monomorphic Ventricular Tachycardia to Long-Term Mortality in ST-Elevation Myocardial Infarction

Abstract

Early ventricular tachycardia (VT) and ventricular fibrillation (VF) are associated with increased in-hospital mortality but do not influence the long-term prognosis in ST-elevation myocardial infarction (STEMI). Recent data advocate a differential approach to the type of arrhythmia and indicate long-term mortality hazard associated with monomorphic VT. We aimed to evaluate the prognostic value of early monomorphic VT compared to nonmonomorphic VT/VF in a nonselected cohort of STEMI patients. Consecutive STEMI patients admitted for primary percutaneous coronary intervention from 2007 to 2010 were included. Clinical characteristics were obtained from the Swedish national SWEDEHEART registry. The occurrence and type of early VT/VF were verified in medical records. All-cause mortality 8 years after STEMI was assessed using the Swedish Cause of Death Register. A total of 2,277 STEMI patients were included (age 66 ± 12 years, 70% male), among them 35 (1.5%) with early monomorphic VT and 115 (5.1%) with nonmonomorphic VT/VF. Patients with monomorphic VT had similar clinical characteristics compared to those with nonmonomorphic VT/VF. In total, 22 patients (63%) with monomorphic VT and 43 (37%) with nonmonomorphic VT/VF died by 8 years of follow-up (p = 0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF in univariate analysis (HR 2.03, 95% CI 1.21 to 3.39, p = 0.007) and after adjustment for age and history of myocardial infarction (MI) (HR 1.74, 95% CI 1.02 to 2.97, p = 0.041). Early monomorphic VT in STEMI is associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF and deserves further studies to refine risk stratification strategies.