Future Research Prioritization: Implantable Cardioverter-Defibrillator Therapy in Older Patients

Background

Although the implantable cardioverter-defibrillator (ICD) is highly effective therapy for preventing sudden cardiac death, there is considerable uncertainty about its benefits and harms in older patients, especially in the presence of factors, other than old age, that increase the risk of death.

Objective

To develop a prioritized research agenda for the Patient-Centered Outcomes Research Institute as informed by a diverse group of stakeholders on the use and outcomes of the ICD in older patients.

Design

The existing literature was reviewed to identify evidence gaps, which were then refined by engaged stakeholders. Using a forced-ranking prioritization method, the stakeholders ranked evidence gaps by importance. For the highest-ranked evidence gaps, relevant recent studies were identified using PubMed, and relevant ongoing trials were identified using ClinicalTrials.gov.

Participants

Eighteen stakeholders, including clinical experts and researchers in the prevention of sudden cardiac death and ICD therapy, representatives from federal and non-governmental funding agencies, representatives from relevant professional societies, health care decision-makers and policymakers, and representatives from related consumer and patient advocacy groups

Key Results

The top 12 evidence gaps prioritized by stakeholders were related to the safety and effectiveness of ICDs in older patient subgroups not well represented in clinical trials, predictors of SCD, the impact of the ICD on quality of life, the use of shared decision-making, disparities in ICD use, risk stratification strategies, patient preferences, and distribution of modes of death in older patients.

Conclusions

In this paper, we identify evidence gaps of high priority for current and future investigations of ICD therapy. Addressing these gaps will likely resolve many of the uncertainties surrounding the use and outcomes of the ICD in older patients seen in clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1007/s11606-015-3411-6) contains supplementary material, which is available to authorized users.KEY WORDS: stakeholder engagement, cardiovascular disease, decision making     

Implantable Cardioverter Defibrillator Therapy for Life-Threatening Arrhythmias in Young Patients

Objectives: This study examined the indications, efficacy and outcomes of implantable cardioverter defibrillator (ICD) use in the pediatric population. Background: ICDs are first-line therapy for adults resuscitated from sudden cardiac death (SCD) or at high risk for life-threatening ventricular arrhythmias. Use of ICDs in children and young adults is infrequent and there are few data regarding this group. Methods: We abstracted and analyzed data for all patients in whom ICDs were implanted. Results: A total of 38 devices were implanted in 27 patients. Age ranged from 6 to 26 years (mean, 14) and weight ranged from 16 to 124 kg (mean, 47). Diagnoses included long QT syndrome (9), hypertrophic cardiomyopathy [6], repaired congenital heart disease [5];, and idiopathic ventricular tachycardia/fibrillation [4]. Indications comprised resuscitated SCD [15], syncope [9], and life-threatening ventricular arrhythmia [3]. Initial device placement was infraclavicular in 13, abdominal in 13 and intrathoracic in 1. Epicardial leads were used with 5 systems. A single coil lead was used in 17. Seven patients, all previously resuscitated from SCD, experienced 88 appropriate successful discharges. There were 6 inappropriate discharges in 3 patients. Mean time to device replacement was 3.1 years (n = 11). Complications included 2 infected systems, 2 lead dislodgments, 2 lead fractures, 1 post-pericardiotomy syndrome, 1 adverse event with defibrillation threshold (DFT); testing, and 1 patient with psychiatric sequelae. No deaths occurred with implanted ICDs. Conclusions: These data demonstrate that ICDs provide safe and effective therapy in young patients. The indications for ICDs as primary preventive therapy remain uncertain.     

植入型心律转复除颤器非适当放电治疗的分析

目的观察植入型心律转复除颤器（ICD）工作情况,通过寻找非适当放电治疗的原因以减少非适当治疗的发生。方法对19例ICD患者随访观察3～57个月,通过ICD储存体心电信号分析．结合病史,确定非适当放电治疗。非适当放电治疗指对窦性心动过速、室上性心动过速、心房颤动、心房扑动、非持续性室性心动过速的ICD放电治疗。结果19例中无ICD放电治疗的患者10例（52．63％）,适当放电治疗6例（31．58％）,非适当放电治疗3例（15．79％）。总计放电治疗11次（9例）,其中非适当放电治疗4次（36．36％）。结论非适当放电治疗的原因复杂多样,其中心房颤动、室上性心动过速是常见原因,调整合适的识别工作模式增强ICD识别功能可以降低非适当放电治疗发生率。     

Implantable Cardioverter Defibrillator Therapy in Patients with Ischemic or Non-Ischemic Cardiomyopathy and Nonsustained Ventricular Tachycardia

BACKGROUND: Mortality benefit from implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) with non-sustained ventricular tachycardia (NS-VT) and inducible VT is well defined. Although NS-VT may suggest an increased risk of sudden cardiac death (SCD) in non-ischemic cardiomyopathy (NICM), the role of ICD therapy is unclear. This retrospective study compares follow-up data in these two groups after ICD implantation. METHODS: 153 consecutive patients with ICD implantation for NS-VT were analyzed. ICM patients received an ICD if they had inducible VT at electrophysiology study (EPS). NICM patients did not routinely undergo EPS before ICD implantation. RESULTS: There were 48 patients (33 males) in NICM group and 105 patients (89 males) in the ICM group. Baseline characteristics including mean ejection fraction (EF), distribution in various New York Heart Association (NYHA) classes, and the mean duration of follow up in the two groups were similar. 50% of the patients in the NICM group and 36% in the ICM group received appropriate therapies (p = 0.106). The mean number of appropriate therapies in the two groups were similar (23.3 +/- 56.7 and 22.5 +/- 59.5 respectively, p = NS). The percentage of patients with inappropriate therapies in the two groups were 27% and 23% respectively (p = NS). Patients in the NICM group received appropriate ICD discharges at a greater rate (p = 0.02). CONCLUSION: Patients undergoing ICD implantation for NICM and NS-VT receive appropriate ICD therapy at a greater rate than those implanted for ICM, NS-VT, and a positive EPS. Although these data do not prove survival benefit in NICM, they suggest a beneficial effect.