Randomized Study of Integrated Evaluation of Conventional Biventricular and Left Bundle Branch Pacing Therapy Effect on Left Ventricular Remodeling and Clinical Outcomes in Patients With Chronic Heart Failure With Reduced Ejection Fraction
Heart failure (HF) is the most common nosology encountered in clinical practice. Its incidence and prevalence increase exponentially with increasing age and it is associated with increased mortality, more frequent hospitalization and decreased quality of life. An initial approach to the treatment of HF patients with reduced left ventricular (LV) systolic function and left bundle branch block (LBBB) was implantation of cardioresynchronization device using biventricular pacing. This has resulted in long-term clinical benefits such as improved quality of life, increased functional capacity, reduced HF hospitalizations and overall mortality. However, conventional cardiac resynchronization therapy (CRT) is effective in only 70% of patients. And the remaining 30% of patients are non-responders to conventional CRT. Subsequently, His bundle pacing (HBP) has been developed to achieve the same results. According to other studies HBP has showed greater improvement in hemodynamic parameters than with conventional biventricular CRT. But, nevertheless, there are significant clinical troubles with HBP. In this regard, in 2017, the left bundle branch pacing (LBBP) was developed, which demonstrated clinical advantages compared to biventricular CRT. This method has become an alternative to HBP due to the stimulation of LBB outside the blocking site, a stable pacing threshold and a narrow QRS duration. A series of case reports and observational studies have demonstrated the efficacy and safety of LBBP in patients with CRT indications. However, it is not enough data about CRT with LBBP effectiveness in LV remodeling, reducing mortality and complications. According to our hypothesis, CRT with LBBP compared with conventional biventricular CRT will significantly improve the clinical outcomes and reverse LV remodeling in patients with chronic HF with reduced LV ejection fraction and reduce the number of non-responders to conventional CRT.
• The patient is willing and able to comply with the protocol and has provided written informed consent;
• Male or female patients aged 18 to 80 years;
• Patients with ischemic or non-ischemic cardiomyopathy;
• Symptomatic HF for at least 3 months prior to enrollment in the study;
• New York Heart Association (NYHA) functional class HF ≥ II;
• Patients with HF in sinus rhythm (SR) with LVEF ≤ 35% (measured in the last 6 weeks prior to enrollment), QRS duration ≥150 ms with LBBB morphology;
• Patients with HF in SR with LVEF ≤ 35% (measured in the last 6 weeks prior to enrollment), QRS duration 130-149 ms with LBBB morphology;
• Patients with HF in SR with LVEF ≤ 35% (measured in the last 6 weeks prior to enrollment), QRS duration ≥150 ms with non-LBBB morphology;
• Patients with symptomatic persistent or permanent atrial fibrillation, HF with LVEF \< 40% (measured in the last 6 weeks prior to enrollment) and an uncontrolled heart rate who are candidates for atrioventricular junction ablation (irrespective of QRS duration);
⁃ Patients with HF, LVEF \< 40% (measured in the last 6 weeks prior to enrollment) and indications for continuous ventricular pacing due to bradycardia;
⁃ Patients who have received a conventional pacemaker or an implanted cardioverter-defibrillator and who subsequently develop symptomatic HF with LVEF \< 40% (measured in the last 6 weeks prior to enrollment) despite optimal medical therapy, and who have a significant proportion of right ventricle pacing;
⁃ Optimal HF medical therapy.