Prognosis after cardiac arrest due to ventricular tachycardia or ventricular fibrillation associated with acute myocardial infarction (the MILIS Study). Multicenter Investigation of the Limitation of Infarct Size.

Previous studies have reached conflicting conclusions about whether cardiac arrest due to ventricular tachycardia (VT) or ventricular fibrillation (VF) in acute myocardial infarction (AMI) is of long-term prognostic significance. The mortality rate in 849 patients with confirmed AMI was analyzed. The mortality rate during the initial hospitalization was higher for patients in whom VT/VF occurred (27% vs 7%, p less than 0.001). The in-hospital mortality rate for patients with primary VT/VF, that is, VT/VF occurring in the absence of hypotension or heart failure, was similar to that of patients who did not have VT/VF (8% vs 7%, difference not significant), whereas the rate for patients with secondary VT/VF was significantly greater than that for patients with no VT/VF (51% vs 7%, p less than 0.001). The timing of occurrence of VT/VF also influenced mortality: Patients in whom VT/VF occurred more than 72 hours after admission had a higher in-hospital mortality rate than did patients in whom it occurred within 72 hours (57% vs 20%, p less than 0.05). All cases of primary VT/VF occurred within the first 72 hours of admission. The long-term mortality rate for hospital survivors was not significantly different for patients who had had VT/VF during acute infarction compared with those who had not (19% vs 21%) (mean follow-up 32 months). Thus, cardiac arrest due to ventricular tachyarrhythmia was associated with a higher in-hospital mortality rate but was not a prognostic factor among hospital survivors. Patients resuscitated from primary VT/VF, which characteristically occurs early after AMI, do not have an adverse prognosis.