Inclusion Criteria:

• Patient with a class I or IIa (1) or (2) indication for implantation of a CRT device according to current available guidelines (with additional QRS criteria on Class IIa (1)):
  • Class I: NYHA II, III, IV, EF ≤ 35%† , LBBB, QRS ≥ 150ms‡;
  • Class IIa (1): NYHA II, III, IV, EF≤ 35%† , LBBB, QRS ≥ 130 to < 150ms‡;
  • Class IIa (2): NYHA II, III, IV, EF≤ 35%†, non-LBBB, QRS ≥ 150ms‡.
• Patient is a:
• ‘Non-responder’ (Part I and Part II - Roll-in and Randomized Only): [This criterion is not applicable to Part III Single-arm]
  • Patients who have a CRT system that is functional and despite an adequate trial of Guideline Directed Medical Therapy (GDMT) and attempts at optimal device programming the patient has not responded to therapy for a minimum of 6 months. Non-response is defined as:
    • EF has remained unchanged or worsened (defined as < 5% increase since implant); and
    • The patient’s clinical status based in the totality of available clinical evidence (such as NYHA Class, exercise tolerance, QOL, or global assessment) has remained unchanged or worsened, as determined by the local Site Enrollment Committee; OR
  • ‘Previously Untreatable’ (Part I, Part II, and Part III- Roll-in, Randomized, and Single-arm):
    • Patients who have a full or partial CRT system, who meet general inclusion criteria and are deemed as ‘previously untreatable’ for one of the following reasons:
    • Patients in whom CS lead implantation for CRT has failed:
      • CS lead implant was attempted but abandoned due any of the following: difficult CS access or anatomy, inadequate lead location, inadequate pacing thresholds, persistent phrenic nerve pacing, or other procedural challenges;
    • CS lead implanted but has been programmed OFF§,
      • LV lead that was implanted but not operational includes patients in whom the LV lead is inoperative or programmed off due to improper function such as high threshold, noncapture, phrenic nerve pacing, lead failure, lead dislodgement, or sub-optimal LV lead location; OR
  • ‘High Risk Upgrade’ (Part I, Part II, and Part III):
    • Patients in whom standard CRT upgrade is not advisable due to known relative contraindication to CS lead implant, for example:
    • Risk of venous occlusion or lesion precluding implant (e.g., multiple existing leads in situ);
    • Risk of pocket infection at co-implanted device site (e.g., co-implant placement or battery change within last 12 months);
    • Considered high risk for CS implant due to co-morbidities (e.g., history of ICM or VT with risk of epicardial pacing induced VT).
• Patients on a stable Guideline Directed Medical Therapy (GDMT).
• Patient must be 18 years old or over.
• Patient has signed and dated informed consent.
• Patient has suitable anatomy for implant of the WiSE CRT System (e.g., adequate acoustic window, LV wall thickness in target implant area ≥ 5 mm, absence of LV wall structural abnormalities which may preclude implant).

† EF used for inclusion criteria and for the Baseline TTE must be measured under these conditions:

• Non-responder Patients: EF measured with BiV ON;
• Previously Untreatable Patients: EF measured with CS Lead OFF (if it exists), or in baseline state (if CS lead does not exist);
• High Risk Upgrade Patients: EF measured in baseline state.

‡ QRS used for inclusion criteria should be measured as the patient presents: Non-responder Patients: BiV QRS, Previously untreatable, high risk upgrade – either intrinsic or RV QRS – patient in their current, optimized state.

§ The CS Lead must be programmed OFF during SOLVE CRT screening.

Exclusion Criteria:

• Pure RBBB.
• LVEDD ≥ 8cm.
• Non-ambulatory or unstable NYHA class IV.
• Contraindication to heparin, chronic anticoagulants, or antiplatelet agents.
• Triple anticoagulant patients who cannot tolerate peri-procedural stopping of anticoagulation therapy.
• Attempted device implant (pacemaker, ICD, CRT, LV lead) or successful co-implant within prior 30 days.
• Patients with planned or expected lithotripsy treatment post implant.
• Life expectancy of < 12 months.
• Chronic hemodialysis.
• Stage 4 or 5 renal dysfunction defined as eGFR < 30.
• Grade 4 mitral valve regurgitation.
• Noncardiac implanted electrical stimulation therapy devices.
• Patients with a prosthetic aortic valve and a non-viable transseptal approach for the electrode implant.
• Patients with a prosthetic mitral valve and a non-viable retrograde aortic approach for the electrode implant.
• Unstable angina, acute MI, CABG, or PTCA within the past 1 month.
• Correctable valvular disease that is the primary cause of heart failure.
• Recent CVA or TIA (within the previous 3 months).
• Patients with a history of paroxysmal or persistent atrial fibrillation/flutter are excluded if they have had a documented AF episode > 30 min or a cardioversion in the past 30 days from screening.
• Patients with permanent AF are excluded if they have intact AV node conduction (RV pacing < 95%).
• Already included in another clinical study that could confound the results of this study.
• Pregnancy.
• Known drug or alcohol addiction or abuse.
• Moderate or severe aortic stenosis.
• Positive test for COVID-19 at screening.
• Subject unable to attend follow-up at the investigative center or unable, for physical or mental reasons, or to comply with the trial's procedures.
• For Part II randomized patients, those who will not tolerate being randomized to the Control Group for 6 months.

Eligibility last updated 6/30/22. Questions regarding updates should be directed to the study team contact.