CRT-D confers improved outcomes vs. ICD in patients with HF, CKD

In a study of patients with HF and moderate to severe chronic kidney disease, use of a cardiac resynchronization therapy defibrillator was associated with lower risk for death or HF hospitalization compared with use of an implantable cardioverter defibrillator.

Researchers analyzed 10,946 patients (mean age, 75 years) with class III or IV HF with reduced ejection fraction and stage III to V CKD eligible for CRT-D from the National Cardiovascular Data Registry ICD Registry.

They compared those who received CRT-D (n = 9,525) with those who received ICD only (n = 1,421), all of whom were fee-for-service Medicare patients at least 65 years of age who underwent ICD implantation with or without CRT between 2006 and 2009.

The primary endpoint was HF hospitalization or death. The secondary endpoint was death. Median follow-up was 30-months and outcomes were determined by review of Medicare claims.

Lower risk with CRT-D

Daniel J. Friedman, MD, cardiology fellow at Duke University Hospital, and colleagues found that after adjustment for risk, the CRT-D group had a lower risk for HF hospitalization or death compared with the ICD group (HR = 0.84; 95% CI, 0.78-0.91).

Additionally, the CRT-D group had reduced risk for death (HR = 0.85; 95% CI, 0.77-0.93) and HF hospitalization alone (subdistribution HR = 0.84; 95% CI, 0.76-0.93) compared with the ICD group.

In-hospital complications did not vary across the range of CKD severity (P = .51), nor 30-day complications (P = .57) or 90-day complications (P = .84), according to the researchers.

The treatment effect of CRT-D did not differ by CKD class for the primary endpoint (P = .15), HF hospitalization (P = .13) or death (P = .69).

CRT-D was more beneficial regarding the primary outcome in patients with left bundle branch block (HR = 0.73; 95% CI, 0.66-0.81) than in those without it (HR = 0.97; 95% CI, 0.86-1.09; P for interaction = .001), according to Friedman and colleagues.

“Taken in sum, the results from this study support the use of cardiac resynchronization therapy independent of kidney function,” Friedman said in a press release. “The treatment is associated with a reduction in risk of [HF] hospitalization and mortality. These results, however, should be confirmed by prospective randomized studies.”

Inappropriate for advanced disease?

In a related editorial, John G.F. Cleland, MD, PhD, and Yura Mareev, MD, PhD, wrote that a major limitation of the study is that it did not have a device-free control group.

“Within 3 years, 61% of those with end-stage renal disease who received an ICD and 54% of those who received CRT-D had died,” Cleland and Mareev, both from the National Heart and Lung Institute, Imperial College, London, wrote. “Implanting a CRT pacemaker can be justified to improve symptoms, even if prognosis is grave. However, ICDs are ineffective and inappropriate for most patients with advanced disease.” – by Erik Swain

Disclosure: Friedman reports receiving educational grants from Boston Scientific. Cleland reports financial ties with Abbott, Amgen, Bayer, Medtronic, Novartis, Phillips, Servier, Sorin, Stealth Biopharmaceuticals and Trevena. Mareev reports receiving educational support from Boston Scientific, Medtronic and Sorin. See the full study for a list of the other researchers’ relevant financial disclosures.