Safety and Effectiveness of Left Bundle Branch Area Pacing Versus Conventional Cardiac Resynchronization Therapy in Heart Failure

Inclusion criteria

• Patient is age 18 years or above, or of legal age to give informed consent specific to state and national law
• Patient meets a guideline-based indication for a de novo CRT-D device
• Primary prevention indication for ICD therapy
• Ischemic or nonischemic cardiomyopathy with LVEF ≤ 35% within 6 months of enrollment (LVEF must be assessed after the subject has been on GDMT for a minimum of 3 months) using an appropriate method of assessment (i.e. Echo, MRI, etc)
• NYHA class II-IV despite maximally tolerated guideline directed medical therapy (GDMT)* for at least 3 months

*GDMT is defined as all four drug classes listed below for at least 3 months prior to enrollment unless the investigator provides justification (e.g., contraindicated, not tolerated or cost): Renin Angiotensin System Inhibitors (ACE, ARB, or ARNI) Evidence based betablockers (metoprolol succinate, carvedilol, bisoprolol) Mineralocorticoid antagonists SGLT2 Inhibitor medications

• Sinus rhythm with left bundle branch block (LBBB) defined as a QRS ≥ 140 ms in men and ≥ 130 ms in women with a predominantly negative deflection (QS or rS in lead V1 and mid QRS notching or slurring in at least two of the following leads: 1, aVL, V1, V2, V5, V6) within 3 months of enrollment
• Patient is willing to participate in LATITUDE™ NXT remote patient monitoring
• Patient is willing and capable of providing informed consent and participating in all testing associated with this investigation at an approved study site and at the protocol defined intervals (Note: Use of a legally authorized representative (LAR) is not allowed)
• Patient plans to remain geographically stable (not permanently moving to another location) and can commit to all study participation requirements (procedure, follow-up visits and testing requirements)

Exclusion criteria

• Persistent or permanent atrial fibrillation (AF) within 3 months prior to enrollment and documented in the medical record
• Frequent premature ventricular contractions (PVCs), atrial arrhythmias, and/or other causes of expected percentage of cardiac physiologic pacing (CPP) delivery below 95% at the time of enrollment
• Non-LBBB conduction abnormalities (including right bundle branch block (RBB) or intraventricular conduction delay (IVCD)) within 3 months prior to enrollment
• Complete, second degree or high degree atrioventricular (AV) block, that requires pacing at the time of enrollment
• Current or prior pacemaker, ICD or CRT implant (Also includes non-transvenous ICD technology and leadless pacemakers)
• Prior or planned mechanical or bioprosthetic tricuspid valve replacement
• Currently receiving or previously received positive inotrope therapy within 3 months prior to enrollment
• Unstable angina, acute myocardial infarction, coronary artery bypass grafting, or percutaneous coronary intervention within 3 months prior to enrollment
• History of heart transplantation or left ventricular assist device (LVAD) implantation
• Less than 1 year of life expectancy at the time of enrollment
• Anticipated heart transplantation or LVAD implantation within 1 year of enrollment
• History of ventricular septal defect (VSD)
• Complex congenital heart disease
• Documented diagnosis of cardiac amyloidosis
• Known occlusion or other reason limiting central venous access for transvenous leads
• Women of childbearing potential who are, or plan to become, pregnant during the course of the study (assessment per investigator's discretion)
• Patient currently requiring dialysis
• Patient with known or suspected sensitivity to Dexamethasone Acetate (DXA)
• Patient with contrast dye allergy or unwilling/able to undergo pre-treatment with steroids and/or diphenhydramine
• Inability or refusal to comply with the follow-up schedule including subject living at such a distance from the investigational site that attending follow-up visits would be unusually difficult or burdensome
• Patient is enrolled in any other concurrent study. Co-enrollment into other studies such as observational studies/registries needs prior written approval by BSC. Local mandatory governmental registries are accepted for co-enrollment without approval by BSC.