Cardiac resynchronization therapy (CRT) can provide real value for patients with severe left ventricular dysfunction, according to new research published in JACC: Clinical Electrophysiology. The analysis focused on patients with a left ventricular ejection fraction (LVEF) of 15% or less.
“Patients with a severely depressed LVEF who present for CRT implant present a treatment challenge,” wrote first author John Rickard, MD, a cardiologist at the Cleveland Clinic’s Heart and Vascular Institute, and colleagues. “Current implant guidelines offer no guidance as to whether CRT is futile or potentially harmful in patients with an extremely poor ejection fraction.”
Rickard et al. explored data from 420 patients with an LVEF of 15% or less and a QRS duration of 120 milliseconds or more. All patients underwent CRT at one of three facilities from April 2003 to May 2014, and more than 72% of patients were men.
Overall, after a mean follow-up period of 5.2 years, 17 patients had a left ventricular assist device (LVAD) implanted, 20 patients had a heart transplant and another 254 patients died. Being younger or a woman were both associated with improved survival free of a LVAD or heart transplant. The same was true for patients with a smaller baseline LV end-diastolic diameter (LVEDD) and the presence of left bundle branch block (LBBB).
The team noted that 298 patients had pre- and post-CRT echocardiograms. Nearly 49% of those patients had an absolute LVEF improvement of more than 5%, which the authors defined as the criteria for a response. Patients who met that criteria were more likely to have a smaller LVEDD or LBBB.
Also, no procedure-related deaths were reported in the cohort.
“Patients with severe LV dysfunction derive benefit from CRT, although at lower rates than traditionally studied patients with higher LVEFs,” the authors concluded. “These data argue against a specific point at which cardiac function becomes so severely dysfunctional that mitigation with CRT is completely precluded. Improvement in LVEF translates into improved survival in this population.”
Read the study in full here.
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