Prediction Efficiency of MADIT-ICD Benefit Score for Outcome in Asian Patients with Implantable Cardioverter-Defibrillator

Background: Not all patients with heart failure derive consistent benefit from prophylactic implantable cardioverter-defibrillator (ICD). We aimed to evaluate the role of MADIT-ICD benefit score in risk-stratifying in Asian patients with left ventricular ejection fraction (LVEF) <= 35%. Methods: In this two-center, retrospective study, a total of 136 patients with LVEF <= 35% who received an ICD for primary prevention were enrolled. The endpoints were defined as the ventricular tachycardia >= 200bpm (VT) or ventricular fibrillation (VF) and non-arrhythmic death. Based on the MADIT-ICD benefit score system, all patients were categorized into three groups: highest benefit group (n = 41), intermediate benefit group (n = 80), and lowest benefit group (n = 15). Results: Forty patients experienced VT/VF and seven died of non-arrhythmic causes during a median follow-up of 44.8 +/- 28.9 months. Kaplan-Meier curves showed that patients in highest benefit group had a worse VT/VF occurrence compared to those in other groups. In the highest benefit group, the predicted risk of VT/VF was 17-fold higher than the risk of non-arrhythmic mortality (41.5% vs 2.4%, P < 0.001). In the intermediate benefit group, the predicted risk of VT/VF was 4.2-fold higher than the risk of non-arrhythmic mortality (26.3% vs 6.3%, P = 0.001). In the lowest benefit group, however, the difference in the corresponding predicted risks was attenuated without statistically significant (13.3% vs 5.1%, P = 0.56). Conclusion: We demonstrate that MADIT-ICD benefit score can be used for the assessment of ICD primary prevention benefits in Asian patients with LVEF <= 35%.