When treating older heart failure (HF) patients, cardiac resynchronization therapy with a defibrillator (CRT-D) is associated with better outcomes than treatment with an implantable cardioverter-defibrillator (ICD) alone, according to new findings published in JACC: Heart Failure.
"At times, the response to cardiac resynchronization therapy (CRT) can be dramatic, resulting in improvements in structural, functional, and quality of life endpoints as well as HF events and death above and beyond those attributable to defibrillator therapy," wrote lead author Emily P. Zeitler, MD, with Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, and colleagues. "Some smaller, nonrandomized studies from mostly single centers suggest that CRT may be associated with these same improvements in a population of older patients with HF. Robust multicenter data on older patients are lacking, however."
The authors examined data from nearly 14,000 patients with heart failure with reduced ejection fraction (HFrEF) who underwent CRT-D and ICD or both from January 2008 to August 2015. All patients were Medicare Part D beneficiaries 65 years old or older.
Device-related complications were high for all patients, the authors wrote, no matter which age or device was being studied.
The highest risk of complication was observed in patients who had ICD implants and were 85 years of age or older. The lowest-risk group was patients 65-74 years old who had CRT-D implants. Bleeding was the most common complication, detected in 5% to 8% of patients.
When looking at the endpoint of HF hospitalization, the authors saw no difference associated with device type for patients younger than 85 years old. For patients 85 years and older, however, CRT-D was associated with fewer HF hospitalizations.
Another key finding from the team was that the mortality rate was high after both 90 days and one year, only growing as patient age increased. At the end of one year, 18% to 33% of patients from each age group and device type had died.
"Reasons for the high mortality rate are unknown because cause of death was not available, but it likely reflects significant competing nonarrhythmic mortality risk, which is difficult to measure from claims data," the authors wrote. "This is problematic because relevant professional guidelines consistently recommend ICD (with or without CRT) only when life expectancy is at least 1 year, but estimating survival is notoriously unreliable and is commonly based on clinical gestalt."
The group also noted that one-year mortality was similar between CRT-D and ICD patients between the ages of 65 and 74 years old. For patients 74 years old and older, however, one-year mortality was lower among CRT-D patients.
“These findings demonstrate significant improvements in mortality and HF hospitalization associated with CRT-D in the oldest patients,” the authors wrote. “Overall mortality and complications attributable to device implantation are higher than previously reported, which, in part, likely reflects an evolving HF population that is increasingly older and comorbid. As such, the inclusion of older patients in future randomized clinical trials of HF interventions would improve understanding of therapies in this growing population.”
Read the full study here.