Leadless left ventricular endocardial pacing in nonresponders to conventional cardiac resynchronization therapy

Abstract

Background Endocardial pacing may be beneficial in patients who fail to improve following conventional epicardial cardiac resynchronization therapy (CRT). The potential to pace anywhere inside the left ventricle thus avoiding myocardial scar and targeting the latest activating segments may be particularly important. The WiSE‐CRT system (EBR systems, Sunnyvale, CA) reliably produces wireless, endocardial left ventricular (LV) pacing. The purpose of this analysis was to determine whether this system improved symptoms or led to LV remodeling in patients who were nonresponders to conventional CRT. Method An international, multicenter registry of patients who were nonresponders to conventional CRT and underwent implantation with the WiSE‐CRT system was collected. Results Twenty‐two patients were included; 20 patients underwent successful implantation with confirmation of endocardial biventricular pacing and in 2 patients, there was a failure of electrode capture. Eighteen patients proceeded to 6‐month follow‐up; endocardial pacing resulted in a significant reduction in QRS duration compared with intrinsic QRS duration (26.6 ± 24.4 ms; P = .002) and improvement in left ventricular ejection fraction (LVEF) (4.7 ± 7.9%; P = .021). The mean reduction in left ventricular end‐diastolic volume was 8.3 ± 42.3 cm3 (P = .458) and left ventricular end‐systolic volume (LVESV) was 13.1 ± 44.3 cm3 (P = .271), which were statistically nonsignificant. Overall, 55.6% of patients had improvement in their clinical composite score and 66.7% had a reduction in LVESV ≥15% and/or absolute improvement in LVEF ≥5%. Conclusion Nonresponders to conventional CRT have few remaining treatment options. We have shown in this high‐risk patient group that the WiSE‐CRT system results in improvement in their clinical composite scores and leads to LV remodeling.

Endocardial left ventricular pacing

“…Of note, 76% of the complications occurred within a center’s first ten implants, suggesting a significant initial learning curve when implanting this system. In a subanalysis of 20 nonresponders to conventional CRT who underwent WiSE-CRT implantation, 55.6% of patients demonstrated improvement in their clinical composite score and 66.7% had an echocardiographic response (either a reduction in LVESV ≥ 15% or improvement in LVEF ≥ 5%) at 6 months [ 33 ]. This demonstrates the utility and clinical efficacy of the WiSE-CRT system in patients who do not respond to conventional CRT, and supports previous evidence from mechanistic studies that endocardial LV pacing may be superior to conventional epicardial pacing via the coronary sinus.…”

Morphometric Characterization of Human Coronary Veins and Subvenous Epicardial Adipose Tissue—Implications for Cardiac Resynchronization Therapy Leads

“…While early battery depletion is still a challenging risk in leadless RV systems, recent leadless LV systems use external pulse generators with ultrasonic and subcutaneous batteries as a power source (60). Similar to conventional pacemakers, pocket problems, including device-related infections, are post-operative complications with leadless CRT systems (60,64). The usual retrograde transaortic implantation of the leadless devices into the LV often necessitates general anesthesia (64).…”

“…Similar to conventional pacemakers, pocket problems, including device-related infections, are post-operative complications with leadless CRT systems (60,64). The usual retrograde transaortic implantation of the leadless devices into the LV often necessitates general anesthesia (64). A transvenous, transseptal implantation is an alternative and would be less invasive (61).…”

“…Recently some authors questioned the necessity of leadless CRT systems (65). However, leadless CRT systems are beneficial for up to half of non-responders to conventional CRT (60,64).…”

The importance of leadless pacemaker positioning in relation to subcutaneous implantable cardioverter-defibrillator sensing in completely leadless cardiac resynchronization and defibrillation systems

“… 1 , 2 Leadless cardiac resynchronization therapy (CRT) can be delivered using the WiSE-CRT system (EBR Systems, Sunnyvale, CA), which improves symptoms and left ventricular (LV) remodeling in patients who are untreatable or nonresponders to conventional CRT. 3 , 4 This system uses ultrasound-based wireless communication between a submuscular transmitter and an endocardial electrode to deliver LV pacing, and requires an existing device capable of delivering continuous right ventricular (RV) pacing to achieve CRT. Currently no single-vendor combined leadless system exists to deliver RV pacing, CRT, and ICD therapy.…”