Leadless Ultrasound-Based Cardiac Resynchronization System in Heart Failure Results from the SOLVE-CRT Randomised Sub-study

M. Seifert (Bernau bei Berlin)¹, J. Singh (Boston)², C. Rinaldi (London)³, P. Sanders (Adelaide)⁴, S. James (South Tees)⁵, I. Niazi (Aurora)⁶, T. Betts (Oxfort)⁷, E. Aziz (Newark)⁸, J. Alison (Melbourne)⁹, A. Auricchio (Lugano)¹⁰, M. Gold (Charleston)¹¹, J. Lindenfeld (Nashville)¹², M. N. Walsh (Indianapolis)¹³, C. Butter (Bernau bei Berlin)^1
1Immanuel Klinikum Bernau Herzzentrum Brandenburg / Kardiologie Bernau bei Berlin, Deutschland; ²Mass General Heart Center Cardiology Boston, USA; ³St Thomas Hospital Cardiology London, Großbritannien; ⁴Royal Adelaide Hospital Cardiology Adelaide, Australien; ⁵South Tees Hospitals NHS Trust Cardiology South Tees, Großbritannien; ⁶Aurora Health Care Cardiology Aurora, USA; ⁷John Radcliffe Hospital Cardiology Oxfort, Großbritannien; ⁸New Jersey Medical School Cardiology Newark, USA; ⁹The Victorian Heart Hospital Cardiology Melbourne, Australien; ¹⁰Fondazione Cardiocentro Ticino Cardiology Lugano, Schweiz; ¹¹Medical University of South Carolina Cardiology Charleston, USA; ¹²Vanderbilt Heart and Vascular Institute Heart Failure and Cardiac Transplantation Nashville, USA; ¹³Ascencion St. Vincent Heart Center Cardiology Indianapolis, USA

 Background: Despite the well-established role of CRT in heart failure, major limitations of CRT are an occasional incidence of unsuccessful coronary sinus (CS) lead placement, one third non-responders in conventional CRT patients and higher complications risk in CRT upgrade procedures. The WiSE® (Wireless Stimulation Endocardial) CRT System is designed to overcome these limitations. Prior non-randomised studies with the WiSE® CRT System have shown high implant success rates and improvement in LV remodeling and heart failure symptoms.
Objectives: Pivotal study to assess the safety and effectiveness of the WiSE® CRT System in an international, randomized, two-arm, double blinded, prospective study (randomized part only).

Method: 99 Patients with indication for CRT and previously failed CRT implant, considered as high-risk upgrade to conventional CRT, or non-responders to conventional CRT underwent device implantation and were then randomised into treatment (47 pts, System ON) and control (52 pts System OFF) groups for 6 months. Primary efficacy endpoints were change in LVESV, LVEDV, LVEF and QRS over 6 months in blinded Echo and ECG core lab analysis.

Results: Mean ∆LVESV (%) -14.6 (-19.6, -9.6); mean ∆LVEDV (%) -8.1 (-11.9, -4.3) and mean ∆QRS (ms) -41.9 (-50.1, -33.7) in the treatment group were significantly lower/shorter than mean ∆LVESV (%) -5.2 (-10.7, 0.2); mean ∆LVEDV (%) -3.0 (-7.0, 1.0) and mean ∆QRS (ms) -1.7 (-7.1,3.8) in the control group, p=0.005; p=0.027 and p=0.001, 95% CI. Mean ∆LVEF (%) 5.4 (3.2, 7.7) in the treatment group increased significantly compared to control group ∆LVEF (%) 2.4 (0.2, 4.5), p=0.048. 8 of 99 pts were attempted from WiSE CRT implant.

Conclusion: This randomized sub-study of the pivotal SOLVE-CRT trial demonstrates that leadless, ultrasound-based endocardial pacing for heart failure is feasible and efficacious showing evidence of left ventricular remodelling and electrical response after 6 month.

Table: Baseline Characteristics

	Teatment n/N (%) or mean ± SD	Control n/N (%) or mean ± SD	p= value
Female Age (years)	13/47 (27.7) 68.1 ± 8.3	9/52 (17.3) 67.4 ± 11.3	0.216 0.735
Previously untreatable High risk upgrade Non-responder	20/47 (42.6) 5/47 (10.6) 22/47 (46.8)	28/52 (53.9) 4/52 (7.7) 20/52 (38.5)	0.525
LVEF (%) LVESV (ml) LVEDV (ml)	29.5 ± 7.8 149.7 ± 61.2 207.8 ± 72.7	28.3 ± 8.3 157.5 ± 63.6 215.0 ± 68.6	0.484 0.536 0.615
Ischemic Atrial fibrillation Renal dysfunction COPD Diabetes	24/47 (51.1) 9/47 (19.2) 13/47 (27.7) 5/47 (10.6) 17/47 (36.2)	25/52 (48.1) 8/52 (15.4) 11/52 (21.2) 10/52 (19.2) 19/52 (15.4)	0.767 0.620 0.451 0.234 0.970
NYHA class II NYHA class III	13/47 (27.7) 34/47 (72.3)	18/52 (34.6) 34/52 (65.4)	0.456