Sustained ventricular arrhythmias in patients receiving thrombolytic therapy - Incidence and outcomes

Background-Sustained ventricular tachycardia (VT) and fibrillation (VF) occ ur in up to 20% of patients with acute myocardial infarction (MI) and have been associated with a poor prognosis. The relationships among the type of arrhythmia (VT versus VF or both), time of VT/VF occurrence, use of thrombo lytic agents, and eventual outcome are unclear. Methods and Results-In the GUSTO-I study, we examined variables associated with the occurrence of VT/VF and its impact on mortality. Of the 40 895 pat ients with ventricular arrhythmia data, 4188 (10.2%) had sustained VT, VF, or both. Older age, systemic hypertension, previous MI, Killip class, anter ior infarct, and depressed ejection fraction were associated with a higher risk of sustained VT and VF (P<0.001). In-hospital and 30-day mortality rat es were higher among patients with sustained VT/VF than among patients with out sustained ventricular arrhythmias (P<0.001). Both early (<2 days) and l ate (>2 days) occurrences of sustained VT and VF were associated with a hig her risk of later mortality (P<0.001). In addition, patients with both VT a nd VF had worse outcomes than those with either VT or VF alone (P<0.001). A mong patients who survived hospitalization, no significant difference was f ound in 30-day mortality between the VT/VF and no VT/VF groups. However, af ter 1 year, the mortality rate was significantly higher in the VT alone and VT/VF groups (P<0.0001). Conclusions-Despite the use of thrombolytic therapy, both early and late oc currences of sustained VT or VF continue to have a negative impact on patie nt outcome; patients with both VT and VF had the worst outcome; and among p atients who survived hospitalization, the 1-year mortality rate was signifi cantly higher in those who experienced VT alone or VT and VF.