CRT not beneficial over standard care in narrow-QRS HF

AMSTERDAM — New data from the EchoCRT study suggest that cardiac resynchronization therapy is of no benefit and may cause harm in patients with narrow-QRS who have echocardiographic left ventricular dyssynchrony.

The study was conducted to evaluate the effect of CRT on morbidity and mortality when added to stable medical therapy in patients with NYHA class III or IV HF, a LV ejection fraction ≤35%, a QRS duration of <130 ms and echocardiographic evidence of LV dyssynchrony. All patients had an implantable cardioverter defibrillator-CRT device (CRT-D) implanted and then were randomly assigned to CRT capability or no CRT capability.

However, EchoCRT was stopped early in March 2013 for futility. At study closure, 809 patients who had been randomly assigned were followed for an average of 19 months. Johannes Holzmeister, MD, from University of Zurich, Switzerland, presented results on these patients at ESC Congress 2013.

The primary outcome, a composite of all-cause mortality or first hospitalization for worsening HF, occurred in 28.7% of the CRT group vs. 25.2% of the control group (HR=1.2; 95% CI, 0.92-1.57). During follow-up, there were 45 deaths in the CRT group vs. 26 in the control group (11.1% vs. 6.4%; HR=1.81; 95% CI, 1.11-2.93). In total, 89.6% of patients met the primary safety endpoint of freedom from CRT-D device complications at 6 months after implantation.

The findings were published simultaneously in The New England Journal of Medicine.

At a press conference, Holzmeister said, “EchoCRT demonstrates no benefit of CRT in HF patients with a relatively normal QRS duration on recommended pharmacological therapy and an ICD. The results provide important and timely guidance to physicians about how to appropriately allocate available resources to the right patients.”

However, due to the early termination of the trial, follow-up of only 19 months and a small number of events, “a firm conclusion about mortality cannot be reached,” he said. Echocardiography remains the best approach for the selection of patients with CRT, he added.

For William T. Abraham, MD, a co-researcher on EchoCRT and director of the division of cardiovascular medicine at The Ohio State University Wexner Medical Center, “This landmark trial is likely the final word on CRT in narrow-QRS HF patients, as not even a hint of benefit was seen,” he stated in a press release. “We can state with confidence that these patients should not receive CRT.”

For more information:

Holzmeister J. Hot Line IV: Late breaking trials on heart failure and acute coronary syndrome. Presented at: the European Society of Cardiology Congress; Aug. 31-Sept. 4, 2013; Amsterdam.

Ruschitzka F. N Engl J Med. 2013;doi:10.1056/NEJMoa1306687.

Disclosure: The study was funded by Biotronik and GE Healthcare. Holzmeister reports consulting for Biotronik and has received research grants from St. Jude Medical and Biotronik. Abraham reports receiving consulting fees from Biotronik, Medtronic and St. Jude Medical.