Use of Primary Prevention Implantable Cardioverter-Defibrillators in a Population-Based Cohort Is Associated With a Significant Survival Benefit

Abstract

Background— Underuse of implantable defibrillators has been previously noted in patients at risk for sudden cardiac death, as well as for survivors of sudden cardiac death. We sought to determine the utilization rates in a primary prevention implantable cardioverter-defibrillator (ICD)–eligible population and mortality in this group compared with a group that had undergone implantation of this therapy. Methods and Results— A retrospective cohort of patients from April 1, 2006, to December 31, 2009, was used to define a primary prevention ICD-eligible population. Two groups were compared on the basis of ICD implantation (no-ICD versus ICD). The primary outcome measure was mortality. Of the 717 patients found to be potentially eligible for a primary prevention ICD, 116 (16%) were referred. The remaining cohort of 601 patients were compared with an existing cohort of primary prevention ICD patients (n=290). A significant survival benefit was associated with primary prevention ICD implantation (hazard ratio, 0.46; 95% CI [0.33–0.64]; P <0.0001). When adjusted for prespecified variables known to be associated with overall mortality and propensity score, a similar survival benefit was seen (hazard ratio, 0.59; 95% CI [0.40–0.87]; P =0.01). Appropriate ICD therapy occurred in 26% of those in the ICD group, during a mean follow-up of 2.7 years. Conclusions— A significant mortality benefit was observed for patients who underwent primary prevention ICD implantation compared with those who did not. Vigilance is required to ensure that patients eligible for primary prevention ICDs are appropriately referred and assessed to allow such patients to benefit from this life-saving therapy.

Current Status of Primary Prevention of Sudden Cardiac Death With Implantable Cardioverter Defibrillator in Patients With Chronic Heart Failure

“…It has been reported that the use of prophylactic ICD implantation was low in clinical practice, even in Western countries. 31, 32 Hoang et al reported that the utilization rate of ICD was 38% among patients with class I indication in USA. 31 Parkash et al reported that only 16% of patients eligible for a primary prevention ICD were referred in a community-based cohort study in Canada, whereas a significant mortality benefit was noted for ICD implantation.…”

“…31 Parkash et al reported that only 16% of patients eligible for a primary prevention ICD were referred in a community-based cohort study in Canada, whereas a significant mortality benefit was noted for ICD implantation. 32 In the present study, the implantation rate of ICD/CRT-D was also low: 30% in group A (LVEF ≤35% and NSVT), 6.6% in group B (LVEF ≤35% but no NSVT), and in total 10.8% in groups A and B. Furthermore, the proportion of patients with prophylactic ICD/CRT-D implantation among those who had FAE was also low: 44% in group A and 9% in group B (Figure 3), indicating that a considerable number of patients did not have ICD implantation despite the positive indication.…”

Frequency and Determinants of Implantable Cardioverter Defibrillator Deployment Among Primary Prevention Candidates With Subsequent Sudden Cardiac Arrest in the Community

“…Recent reports have suggested that ICDs may be significantly underused in the community for both primary and secondary prevention. [13][14][15] However, the extent of deployment of the primary ICD among eligible subjects who eventually experience a cardiac arrest in the general population has not been studied previously. We therefore sought to evaluate the frequency and potential determinants of nondeployment of the primary ICD among subjects who experienced SCA in the community.…”

Prophylactic Implantation of Implantable Cardioverter-Defibrillator for Japanese Patients With Heart Failure

“…16 In a populationbased study in Canada, only 16% of patients eligible for primary-prevention of ICD (ischemic and non-ischemic cardiomyopathy) received an ICD. 17 Other studies in the United States have also suggested underuse (30.7%) of ICD, even for secondary prevention in survivors of SCD. 18 Satake et al 10 also describe that in patients with EF ≤35% with or without NSVT, the proportion of prophylactic ICD implantation was only 34 of 315 patients (10.8%).…”