Heart Failure, Systolic Bundle Branch Block, Left
Conditions
Brief summary
This 2x2 randomized crossover feasibility study will evaluate the therapeutic value of adding pacing from the left ventricular lead to Left Bundle Branch Area Pacing (LBBAP) using a cardiac resynchronization therapy defibrillator (CRT-D). This combined therapy is known as Left Bundle Branch Optimized Cardiac Resynchronization Therapy (LOT-CRT) and will be compared to LBBAP therapy over sequential 6-month periods in CRT-indicated patients with LBBB. Primary and secondary outcomes are echocardiographic changes. Exploratory assessments will include NT-proBNP and subject-reported quality of life (KCCQ). An observational treatment arm will include subjects who have not been randomized due to unsuccessful implant for real-world observational analysis
Interventions
CRT-D programmed for LBBAP (LV lead OFF)
CRT-D programmed for LOT-CRT (LBBAP + LV lead ON)
ICD programmed for LBBAP
Sponsors
Study design
Eligibility
Inclusion criteria
* Subject meets current ACC/AHA/HRS guidelines for implantation of a CRT-D device. * Subject has documented LVEF ≤ 35% within 60 days of enrollment. * Subject meets the criteria for presence of Strauss-defined LBBB. * Subject meets NYHA classification II or III. * Subject is willing and able to provide written consent. * Subject is at least 18 years of age at the time of consent. * Subject is geographically stable and willing and able to complete study procedures, including follow-up visits. * The subject's medical records must be accessible by the enrolling site over the follow-up period.
Exclusion criteria
* Subject has documented myocardial infarction before enrollment. * Subject has non-LBBB conduction patterns such as Right Bundle Branch Block (RBBB) or non-specific IVCD. * Subject has 2nd or 3rd degree AV block. * Subject has persistent or permanent atrial fibrillation (AF) or atrial flutter (AFL). * Subject has intrinsic (non-paced) QRS duration ≤ 120ms. * Subject with previous or existing pacemaker (including transvenous and transcatheter pacing system), Implantable Cardioverter Defibrillator (ICD, transvenous) or CRT-D (transvenous) device or leads. * Subject has contraindications for screw-in transvenous lead placement (e.g., mechanical right heart valve). * Subject underwent valve surgery within 90 days prior to enrollment. * Subject is unable or unwilling to undergo baseline CMR imaging, if previously collected CMR images are unavailable or do not meet minimum acceptable criteria. * Subject is post-heart transplantation or is actively listed on the transplantation list. * Subject is implanted with a left ventricular assist device (LVAD). * Subject has severe renal disease. * Subject is on continuous or uninterrupted infusion (inotropic) therapy for heart failure. * Subject has complex and uncorrected congenital heart disease. * Subject has life expectancy of less than 12 months. * Subject is pregnant or breastfeeding. * Subject is enrolled or planning to enroll in a concurrent clinical study that may confound the results of this study, without documented pre-approval from a Medtronic study manager.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Left ventricular ejection fraction (LVEF) | Baseline, 6 months, 12 months | Change in LVEF assessed by echocardiography during each therapy period (baseline to 6 months, 6 months to 12 months). |
| Left ventricular end-systolic volume (LVESV) | Baseline, 6 months, 12 months | Change in LVESV assessed by echocardiography during each therapy period (baseline to 6 months, 6 months to 12 months). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Left ventricular ejection fraction (LVEF) | Baseline, 6 months | Change in LVEF assessed by echocardiography from baseline to 6 months |
| Left ventricular end-systolic volume (LVESV) | Baseline, 6 months | Change in LVESV assessed by echocardiography from baseline to 6 months. |