br Conflict of interest br Introduction The use

Conflict of interest
Introduction The use of implantable defibrillation devices such as an implantable cardioverter–defibrillator (ICD) or a cardiac resynchronization therapy device with a defibrillator (CRT-D) is the primary therapy for improving prognoses of patients with life-threatening ventricular tachyarrhythmias/ventricular fibrillation (VT/VF) [1]. In the Antiarrhythmics versus Implantable Defibrillators (AVID) study, the superiority of defibrillation therapy was established by comparing prognoses of patients with ICD implantation to that of those who received therapy with class III antiarrhythmic agents such as amiodarone or sotalol for secondary prevention of VT/VF [2]. In patients with implantable defibrillation devices, i.e., an ICD/CRT-D, additional preventive therapy for VT/VF would not be required at least for reducing mortality, although several reports have described the usefulness of preventive therapy for reducing frequent defibrillations [1–3]. Contrarily, several recent reports have documented the correlation between frequent defibrillation shocks and higher mortality in patients with a CRT-D device and congestive prosecute failure [4]. In such reports, myocardial damage caused by the frequent shocks has been considered the reason for the poorer prognosis [5]; however, the frequent VT/VF episodes may just be a surrogate marker for more serious underlying heart disease, which then determines the prognosis [6]. However, if the former hypothesis is correct, preventive therapy for VT/VF may result in a better prognosis in patients with an ICD/CRT-D. In the present study, we retrospectively analyzed the patients who were implanted with a defibrillation device, i.e., an ICD/CRT-D, and compared their prognoses to those with and without successful VT ablation in order to clarify the role of preventive therapy in those patients.
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Conflict of Interest
Acknowledgment This study was partly supported by a Grant-in-Aid for Scientific Research 2011–2013 from the Ministry of Education and Science (No. 11838015).
Introduction Patients with inotrope-dependent class IV end-stage heart failure (HF) have an extremely poor prognosis with medical therapy alone [1]. For these patients, cardiac transplantation or left ventricular assist device (LVAD) implantation is a suitable option to improve the morbidity and mortality rates. However, because of poor number of donors, legal issues, or financial cost, these therapies could not be used widely especially in non-Western countries. A significant proportion of HF patients with depressed left ventricular ejection fraction (LVEF) has abnormal electrical activation that is associated with cardiac dyssynchrony. Biventricular pacing has been shown to improve the prognosis of these patients [2]. Recent clinical evidences have shown that cardiac resynchronization therapy (CRT) has made remarkable progress for patients with HF [3–5]. According to a previous report [6], even in patients with New York Heart Association (NYHA) class IV HF, CRT significantly improves mortality and hospitalization rates. However, hemodynamically unstable severe HF patients who require inotropes are usually excluded from major CRT trials, and the current guidelines do not recommend CRT as a therapeutic option for such patients [7,8]. Accordingly, there are limited data about CRT implantation in class IV HF patients on continuous inotropic support, and the efficacy of CRT for such patients is not well established.
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Discussion There are several reports about the clinical outcomes of patients with end-stage HF. The REMATCH trial reported extremely poor outcomes in the medical therapy—only group in patients with end-stage HF [1]. In that study, the optimal medical therapy group included 75% inotrope-dependent HF patients and the 1-year survival rate was only 25%. In relation to the comparison with LVAD patients, the HeartMate II trial studied the outcomes in continuous-flow LVAD patients [11]. Even in those patients, the 1- and 2-year survival rates were 68% and 58%, respectively. Our patients had similar baseline characteristics except that most had non-ischemic HF. However, the 1-year survival rate in our study population after CRT was 81%, which supports the favorable effects of CRT in patients with inotrope-dependent HF.