Conference Coverage

CRT boosts heart failure survival in extended follow-up


AT AHA 2022

– Extended follow-up of patients with heart failure enrolled in the RAFT trial strengthens the case for starting treatment early with a cardiac resynchronization therapy plus defibrillation (CRT-D) device in appropriate patients.

RAFT, which compared CRT-D with treatment with an implantable cardioverter defibrillator (ICD) alone, showed that the early survival benefit produced by CRT-D during an average 40-month follow-up in the original trial persisted during an additional mean follow-up of about 5 years. This result strengthens the case for starting treatment early with a CRT-D device in appropriate patients with heart failure.

Dr. John L. Sapp, professor of medicine, Dalhousie University, Halifax, Nova Scotia Mitchel L. Zoler/MDedge News

Dr. John L. Sapp

During extended follow-up of more than half of the enrolled patients, out to an average of 7.6 years overall and to an average of 12.9 years among survivors, patients who received a CRT-D device had a significant 21% relative reduction in their rate of all-cause mortality compared with randomized patients who received an ICD and no cardiac resynchronization, John L. Sapp, MD, reported at the American Heart Association scientific sessions.

The primary results of RAFT were first reported in 2010.

This magnitude of a survival benefit among the patients originally randomized to CRT is “dramatic,” given that many of the comparator patients who initially received no CRT likely crossed over to receive a CRT-D device once the initial, randomized 4 years of the study finished, commented Lynne W. Stevenson, MD, director of cardiomyopathy and the Lisa M. Jacobson Professor of Cardiology at Vanderbilt University Medical Center in Nashville, Tenn., who was not involved with the study.

‘CRT can remap heart failure trajectory’

The new findings “strengthen our conviction that CRT can remap the trajectory” of selected patients with heart failure, and that “candidates for CRT should be vigorously identified,” Dr. Stevenson said in an interview.

She also noted that the benefit with extended follow-up was “strikingly parallel” to that seen at 12 years after the addition of an ACE inhibitor for mild heart failure during the 4 years of the landmark SOLVD trial. The new RAFT extended follow-up, as well as the 12-year follow-up of the SOLVD trial, “support the concept that longer follow-up reveals vital information not provided by the relatively short randomized trial period,” she said.

“The new data say ‘don’t delay starting CRT in appropriate patients with heart failure,’ and ‘don’t think of CRT as just a treatment that makes patients feel better.’

“The totality of these data shows that CRT also treats the underlying heart muscle weakness, which helps patients live longer. Previous data showed that patients with left bundle branch block eligible for CRT are unlikely to respond well to the usual, recommended heart medications so it is important to start treatment with CRT-D early,” declared Dr. Stevenson, who cochaired the session where Dr. Sapp gave his report.

RAFT randomized 1,798 patients with New York Heart Association (NYHA) class II or III heart failure, a left ventricular ejection fraction of 30% or less, and an intrinsic QRS duration of at least 120 msec to receive either a CRT-D or ICD device. The study’s primary endpoint was death from any cause or hospitalization for heart failure. After an average 40 months of randomized follow-up, the primary endpoint occurred in 40% of the patients with an ICD and in 33% of those with a CRT-D device, a significant 25% relative reduction linked with CRT-D use. Both endpoint components contributed to the combined result significantly and to about the same extent, and the incremental benefit from CRT-D was significant for patients with NYHA class II heart failure as well as for those with class III.

However, prespecified subgroup analyses showed that the incremental benefit from CRT-D was significantly limited to patients with an intrinsic QRS duration of at least 150 msec, while in those with a duration of 120-149 msec CRT-D had a neutral effect compared with ICD. The same pattern also appeared when the analysis split patients into those with a left bundle branch block, who significantly benefited from CRT-D, but the initial benefit was not apparent in patients with right bundle branch block.


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