Long-term survival of multicenter automatic defibrillator implantation trial (MADIT) II-eligible patients in Taiwan

Background: The Multicenter Automatic Defibrillator Implantation Trial (MADIT) II showed that use of a prophylactic implantable cardioverter defibrillator (ICD) improved the survival of patients with poor left ventricular ejection fraction after myocardial infarction. The major concerns about primary ICD prevention in Asian countries are the long-term survival and the incidence of sudden cardiac death. Whether long-term outcomes within the Taiwanese population are comparable to the MADIT II trial remains unclear. Methods: We retrospectively reviewed the clinical records of 1909 inpatients who had both myocardial infarction and heart failure in the discharge diagnoses from Jan. 2001 through Dec. 2006, and 313 patients without ICD implantation who satisfied the MADIT II criteria were included for survival analysis. Results: After 4.60 ± 4.31 years of follow-up, 152 (49%) patients had died. Of these patients, 68 (45%) died of sudden cardiac death, similar to the conventional group (patients without ICD implantation) in the MADIT II study (51%). The Kaplan-Meier curve showed that survival during the first two years in this cohort was inferior to the conventional group of the MADIT II population. After two years, the survival curve was similar to the conventional group but still inferior to the defibrillator group in the MADIT II study. Multivariate Cox regression analysis showed old age and blood urea nitrogen > 25 mg/dL were independent predictors of mortality. A history of percutaneous coronary intervention was associated with lower mortality. Conclusions: The long-term outcomes of Taiwanese patients who are eligible within MADIT II criteria are similar to the conventional group in the MADIT II study.