In this prospective, randomized, multicenter, open-label interventional clinical trial, the investigators' aim to test the effect of Cardiac Resynchronization Therapy (CRT) in cases of new-onset and persistent Left Bundle Branch Block (LBBB) occurring in the context of Transcatheter Aortic Valve Implantation (TAVI), in patients with moderately reduced left ventricular systolic function (35% \< EF \< 55%). The investigators hypothesize that in patients with persistent LBBB developing after TAVI and mildly reduced left ventricular systolic function (35% \< EF \< 55%), early postoperative CRT implantation favorably influences the process of myocardial reverse remodeling by reducing electromechanical dyssynchrony, thereby decreasing the combined endpoint of heart failure-related hospitalizations and mortality at one year.
Age over 18 years
Successful and complication-free TAVI implantation for significant aortic stenosis
Signed informed consent after detailed patient information
New-onset LBBB wider than 130 ms after TAVI, persisting at the time of planned discharge (assessed postoperatively on or after day 5)(21)
Pre-existing right bundle branch block, or prior pacemaker/ICD implantation associated with significant (>20%) ventricular pacing
Progression of LBBB during hospitalization to a degree indicating pacemaker implantation (e.g., Mobitz II or third-degree AV block, alternating bundle branch block) before the planned discharge date
Concomitant severe valvular disease of other valves (mitral, pulmonary, or tricuspid)
Severe infection and/or septic state