NEW ORLEANS -- Among patients with heart failure, conduction system pacing-guided cardiac resynchronization therapy was associated with improvements in left ventricular ejection fraction (LVEF) compared with standard biventricular pacing, the randomized pilot HOT-CRT trial showed.
In patients who were treated with left bundle branch area pacing or His bundle pacing, the average increase in LVEF was 12.4% versus 8% with biventricular pacing at 6 months (P=0.02), reported Pugazhendhi Vijayaraman, MD, of Geisinger Wyoming Valley Medical Center in Wilkes-Barre, Pennsylvania, during the Heart Rhythm Society annual meeting.
"An increase of 12.4% in ejection fraction is certainly clinically meaningful," he told Ƶ.
Use of conduction system pacing proved successful in 96% of the patients compared with 82% of the patients in the biventricular pacing group, Vijayaraman said.
"Traditionally, biventricular pacing is used for cardiac resynchronization therapy, but about 30% of patients have less than optimal response to biventricular pacing," he noted. "Our approach has been to utilize conduction system pacing as a mainstay for trying to achieve cardiac resynchronization."
"His-Purkinje conduction system pacing utilizing His bundle pacing or left bundle branch area pacing has emerged as an alternative to biventricular pacing in patients requiring cardiac resynchronization therapy," he said. "When looking at both cardiac resynchronization options, we believe this should be a positive signal for physicians who are recommending His-Purkinje conduction system pacing as a treatment for their patients."
"We hope the results of this trial will give physicians an alternative option for consideration that will ultimately improve clinical outcomes and overall patient care," he added.
Of note, there was no significant difference in safety endpoints between the groups.
"This sets the stage for additional clinical trials with harder endpoints, such as death or hospitalization for heart failure, and those trials are coming," Vijayaraman said.
Press conference moderator Fred Kusumoto, MD, of the Mayo Clinic in Jacksonville, Florida, noted that research is "focusing significantly on how to pace the ventricle in a physiological manner for those folks who have abnormal physiologic activation or who require pacing. Cardiac resynchronization therapy has been around for a long time, with clinical outcomes that have been established in certain patient groups."
"This technique using either pacing from the His bundle or more distally in the left bundle holds promise in trying to then more physiologically activate the ventricles. And there are surrogate markers such as ejection fraction that seem to be better, while we are waiting for harder clinical outcomes that will impact the patients," he continued. "For certain groups of patients, at this point, conduction pacing could certainly be an option, especially if there are anatomical reasons standard cardiac resynchronization therapy can't be performed."
The (His-Purkinje Conduction System Pacing Optimized Trial of Cardiac Resynchronization Therapy versus Biventricular Pacing) trial was a prospective, randomized, controlled, single-blinded study conducted at a single health system, with eight implanters working across three centers.
The researchers enrolled 100 patients with an LVEF less than 50% from April 2021 to November 2022. They were randomized 1:1 to conduction system-guided pacing or biventricular pacing.
Among the two groups, mean age was 69-71, and the majority were men. Similar proportions had hypertension, diabetes, coronary artery disease, chronic kidney disease, and nonischemic cardiomyopathy.
Vijayaraman said the study should be considered a pilot trial that was not statistically powered for clinical outcomes. Moreover, the trial was limited in that it was conducted in a rural area, among predominantly white men.
Disclosures
Vijayaraman reported relationships with Medtronic, Abbott, Eaglepoint LLC, Pacertool, Boston Scientific, and Biotronik, and a patent on a His bundle pacing delivery tool.
Kusumoto reported no relationships with industry.
Primary Source
Heart Rhythm Society
Vijayaraman P, et al "His-Purkinje conduction system pacing optimized trial of cardiac resynchronization therapy versus biventricular pacing (HOT-CRT): a randomized, controlled, pilot clinical trial" HRS 2023.