BACKGROUND:Landmark studies have demonstrated the safety and efficacy of implantable cardioverter-defibrillators (ICDs) in selected stable ambulatory patients with heart failure (HF) with a reduced ejection fraction receiving optimal medical therapy. It is not known whether a recent hospitalization for HF before ICD placement is associated with subsequent outcomes. METHODS:A post hoc analysis was performed of Medicare beneficiaries enrolled in the National Cardiovascular Data Registry's ICD Registry with a known diagnosis of HF and an ejection fraction ≤35% underdoing a new ICD placement for primary prevention. Patients were grouped based on the timing of ICD placement from the last hospitalization for HF. The association between timing of ICD placement and outcomes was assessed by using multivariable logistic regression models. RESULTS:The final analytic cohort included 81 180 patients undergoing initial ICD placement for primary prevention who were currently hospitalized for HF (n=11 563, 14%), hospitalized for HF within 3 months (n=6252, 8%), or hospitalized for HF >3 months previously or had no previous hospitalizations for HF (n=63 365, 78%). Patients currently or recently hospitalized for HF had a higher unadjusted composite periprocedural complication rate (2.60% versus 1.71% versus 1.25%, P<0.001). After adjusting for potential confounders, patients currently hospitalized for HF were at higher risk for death (odds ratio, 2.25; 95% CI, 2.02-2.52; P <0.001) and all-cause readmission (odds ratio, 1.89; 95% CI, 1.79-1.99; P <0.001) at 90 days. CONCLUSION:Older patients currently or recently hospitalized for HF undergoing initial ICD placement for primary prevention experienced a higher rate of periprocedural complications and were at increased risk of death in comparison with those receiving an ICD without recent HF hospitalization. Additional prospective, real-world, pragmatic, comparative effectiveness studies should be conducted to define the optimal timing of ICD placement.

Catheter ablation of ventricular tachycardia (VT) has evolved in recent years, especially in patients with ischemic heart disease. Data from prospective studies show that VT catheter ablation reduces the risk of recurrent VT; however, there is a paucity of data on the effect of VT catheter ablation on mortality and patient-centered outcomes such as quality of life. Performing randomized clinical trials of VT catheter ablation can be fraught with challenges, and, as a result, several prior trials of VT catheter ablation had to be stopped prematurely. The main challenges are inability to blind the patient to therapy to obtain a traditional control group, high crossover rates between the 2 arms of the study, patient refusal to participate in trials in which they have an equal chance of receiving a "pill" vs an invasive procedure, heterogeneity of mapping and ablation techniques as well as catheters and equipment, rapid evolution of technology that may make findings of any long trial less relevant to clinical practice, lack of consensus on what constitutes acute procedural and long-term success, and presentation of patients to electrophysiologists late in the course of their disease. In this article, a panel of experts on VT catheter ablation and/or clinical trials of VT catheter ablation review challenges faced in conducting prior trials of VT catheter ablation and offer potential solutions for those challenges. It is hoped that the proposed solutions will enhance the feasibility of randomized clinical trials of VT catheter ablation.