Heidenreich, Paul A.

Background— Prior studies have demonstrated low use of implantable cardioverter defibrillators (ICDs) as primary prevention, particularly among women and blacks. The degree to which the overall use of ICD therapy and disparities in use have changed is unclear. Methods and Results— We examined 11 880 unique patients with a history of heart failure and left ventricular ejection fraction ≤35% who were ≥65 years old and enrolled in the Get With the Guidelines–Heart Failure (GWTG-HF) program from January 2005 through December 2009. We determined the rate of ICD use by year for the overall population and for sex and race groups. From 2005 to 2007, overall ICD use increased from 30.2% to 42.4% and then remained unchanged in 2008 to 2009. After adjustment for potential confounders, ICD use increased significantly in the overall study population during 2005 to 2007 (odds ratio, 1.28; 95% confidence interval, 1.11–1.48 per year; P =0.0008) and in black women (odds ratio, 1.82; 95% confidence interval, 1.28–2.58 per year; P =0.0008), white women (odds ratio, 1.30; 95% confidence interval, 1.06–1.59 per year; P =0.010), black men (odds ratio, 1.54; 95% confidence interval, 1.19–1.99 per year; P =0.0009), and white men (odds ratio, 1.25; 95% confidence interval, 1.06–1.48 per year; P =0.0072). The increase in ICD use was greatest among blacks. Conclusions— In the GWTG-HF quality improvement program, a significant increase in ICD therapy use was observed over time in all sex and race groups. The previously described racial disparities in ICD use were no longer present by the end of the study period; however, sex differences persisted.

Background— Outcome data for patients receiving implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy–defibrillator (CRT-D) devices treated outside of clinical trials are lacking. No clinical trial has evaluated mortality after device implantation or after shock therapy in large numbers of patients with implanted devices that regularly transmit device data over a network. Methods and Results— Survival status in patients implanted with ICD and CRT devices across the United States from a single manufacturer was assessed. Outcomes were compared between patients followed in device clinic settings and those who regularly transmit remote data collected from the device an average of 4 times monthly. Shock delivery and electrogram analysis could be ascertained from patients followed on the network, enabling survival after ICD shock to be evaluated. One- and 5-year survival rates in 185 778 patients after ICD implantation were 92% and 68% and were 88% and 54% for CRT-D device recipients. In 8228 patients implanted with CRT-only devices, survival was 82% and 48% at 1 and 5 years, respectively. For the 69 556 ICD and CRT-D patients receiving remote follow-up on the network, 1- and 5-year survival rates were higher compared with those in the 116 222 patients who received device follow-up in device clinics only (50% reduction; P <0.0001). There were no differences between patients followed on or off the remote network for the characteristics of age, gender, implanted device year or type, and economic or educational status. Shock therapy was associated with subsequent mortality risk for both ICD and CRT-D recipients. Conclusions— Survival after ICD and CRT-D implantation in patients treated in naturalistic practice compares favorably with survival rates observed in clinical trials. Remote follow-up of device data is associated with excellent survival, but arrhythmias that result in device therapy in this population are associated with a higher mortality risk compared with patients who do not require shock therapy.