medwireNews: A leadless, ultrasound-based, left ventricular (LV) endocardial pacing system reduces mean LV end systolic volume (ESV) in patients with heart failure who are eligible for cardiac resynchronization therapy (CRT), suggests the SOLVE-CRT study published in JAMA Cardiology.
A total of 183 patients for whom conventional CRT using a coronary sinus lead had failed or who were at high risk for a CRT upgrade were implanted with the WiSE CRT system. This delivers ultrasound energy via a subcutaneous transmitter and battery to a leadless LV endocardial pacing electrode implanted within the endocardium. The system requires a co-implant capable of right ventricular pacing, such as a pacemaker, defibrillator, or CRT.
At 6 months, LVESV was reduced from baseline by a significant 16.4% (an absolute mean decrease of 25 mL) in the 100 patients included in the efficacy cohort, compared with a performance goal of 9.3%. Additionally, the implant had a high 95.5% success rate and 80.9% of the total 183 study participants did not experience device-related or procedure-related type I complications, such as system events, vascular events, strokes, or cardiac perforations, significantly higher than the 70% goal.
“[F]or patients with failed coronary sinus lead placement for CRT, a leadless LV pacing system using ultrasound energy holds promise as a viable alternative,” say Jagmeet Singh (Massachusetts General Hospital, Boston, USA) and co-investigators.
They add that benefits to the WiSE CRT System include “patient-specific endocardial positioning of the electrode, unconstrained by the coronary venous anatomy and without the risks of lead fractures, venous obstruction, mitral regurgitation, and endocarditis.” Also, the implanted electrode is “efficiently endothelialized,” due to having a woven polyester jacket, which prevents the need for prolonged anticoagulant therapy.
Editorialist Fred Kusumoto (Mayo Clinic, Jacksonville, Florida, USA) comments that the study “provides our most comprehensive evaluation of this exciting technology,” while pointing out caveats such as the short follow-up duration and limited information on specific placement of the receiver electrode.
In SOLVE-CRT, Singh and co-workers evaluated the leadless pacing system in patients classified as previously untreatable, such as those who had a full or partial CRT system but were not receiving CRT because of lead failures or issues, or who were at high-risk because of contraindications for a standard CRT upgrade, such as venous occlusion or pocket infection. Nonresponders who had suboptimal responses to conventional CRT were also included at study initiation; however, this group was excluded from continuing the study as the threshold for safety and effectiveness in these patients differed from that of the others.
The trial combined data on 108 patients from a randomized study and 75 from a separate single-arm study. The patients in the randomized study all had the WiSE CRT device implanted and were then randomly assigned to either have the system turned on or off (control). At 6 months, the control group could choose to activate their device and all patients were followed-up for a further 6 months. The patients in the single-arm study also had the WiSE CRT device implanted and were followed-up for 6 months. The 100 patients in the efficacy cohort included 25 from the randomized study and all 75 from the single-arm study, while the safety outcomes were assessed in all 183 patients.
The mean age of the participants was 68 years and 76–77% were men. Most of the patients had a class I CRT indication, at 64–69%, and were classified as New York Heart Association Class III, at 65%.
Type 1 complications occurred in 19.1% of patients and included study device system events in 6.6%, vascular events in 2.7%, and strokes in 1.6%.
“As is typical in initial studies with a novel device, observed complication rates were higher in the early phases and decreased over time,” say the researchers. They attribute the decrease to a protocol change that allowed transseptal access, enhanced training, and mandated use of real-time echocardiography.
The authors conclude that the novel WiSE CRT system “may represent an alternative to conventional CRT implants in some HF patient populations.”
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JAMA Cardiol 2024; doi:10.1001/jamacardio.2024.2050
JAMA Cardiol 2024; doi:10.1001/jamacardio.2024.2067
