Prognostic comparison between implantable cardioverter-defibrillator and amiodarone in cancer patients

Background Implantable cardioverter-defibrillator (ICD) are demonstrated to substantially improve survival outcomes compared to amiodarone. However, the effectiveness of ICD compared to amiodarone in cancer patients remains unclear. Cardiovascular management in cancer patients needs careful consideration of various factors, including the stage of cancer progression. We evaluated the relative effectiveness of ICD over amiodarone in cancer patients. Methods and Results In our retrospective cohort study, cancer registry data were linked with administrative data to identify patients who were newly prescribed amiodarone or underwent ICD implantation between 2010 and 2015 at 36 hospitals in Osaka Prefecture, Japan. From a database of 161,125 cancer patients, we identified 339 patients who were newly prescribed amiodarone (N = 281) or underwent ICD implantation (N = 58) to compare prognosis between two groups and a median follow-up period of 762 days. Kaplan–Meier analysis revealed that the ICD group had significantly reduced risk of all-cause mortality than the Amiodaron group (Log-rank test, p < 0.003). Multivariable Cox proportional hazard regression model showed that ICD was an independent prognostic factor (Hazard ratio: 0.47, 95% confidence interval: 0.29 - 0.79, p=0.004). These results were confirmed in a propensity-matched analysis. Among patients with cancer stage: in situ or localized, no significant difference in survival risk was observed between the ICD and Amiodarone groups, and ICD was not significantly associated with all-cause death. Conversely, among patients with cancer stage: regional or distant, the ICD group had significantly reduced risk of all-cause death than the Amiodaron group, and ICD was an independent prognostic factor. Conclusion In cancer patients, ICD may improve long-term prognosis compared to amiodarone, especially in patients with advanced cancer stages.