Clinical Research Directory

High Intensity His Bundle Pacing in Heart Failure Patients With Narrow QRS Outcome Study

Cardiac Resynchronization Therapy (CRT) decreases heart failure hospitalizations and mortality and increases left ventricular Ejection Fraction (EF) in patients with dilated cardiomyopathy, left bundle branch block and QRS duration \>130msec. His bundle pacing has a similar effect in this category of patients. However, CRT is not beneficial in heart failure (HF) patients with narrow QRS. His-bundle pacing delivers physiological ventricular activation and has been shown to improve acute hemodynamic function in patients with heart failure, a prolonged PR interval, and either a narrow QRS or RBBB through AV delay optimization. We observed an acute hemodynamic effect during application of higher pacing output (3.5 Volts/1 msec) in HF patients with dilated or ischemic cardiomyopathy and narrow QRS independently of the paced QRS duration or AV delay shortening. This is a single-center, prospective randomized single-blinded study, recruiting a sub-population of patients with heart failure (dilated or ischemic cardiomyopathy, EF\<50%, narrow QRS (\<110 msec), in optimal medical treatment who have an indication for ICD.

"Physiological vs Right Ventricular Pacing Outcome Trial Evaluated for bradyCardia Treatment" (PROTECT-HF)

The PROTECT-HF multi-centre randomised controlled trial will compare two different pacing approaches for treating patients with slow heart rates. In it the investigators will compare a long-standing standard approach for pacing; right ventricular pacing, with a new form of pacing, physiological pacing (His and Left bundle area pacing) in 2600 patients. Patients will be allocated at random to receive either right ventricular pacing or physiological pacing. Endpoint measurements will be undertaken at baseline, and at six-monthly intervals post-randomisation. Treatment allocation will be blinded to the endpoint assessor and the patient. Recruitment and pacemaker implantation will be carried out at each participating centre. The primary analysis will be intention to treat. The investigators will also perform an on-treatment analysis. 2048 patients are needed to detect the expected effect size with 85% power. A total of 2600 patients will be recruited to allow for patient drop-out and crossover. 500-patient sub-study will assess within patient, and between groups, echocardiographic changes over a 24-month period to try and improve mechanistic understanding of PICM (Pacing Induced Cardiomyopathy).

Pacing to Maintain Physiologic Ventricular Activation

Right ventricular pacing causes ventricular dyssynchrony and may be associated with impaired outcome. In the last decade, several approaches for more physiological pacing became available and were implemented in the latest guidelines. However, compared to conventional device implantation, cardiac resynchronization, His bundle pacing and left bundle area pacing remain demanding procedures in the individual case. Goal of the single center observational "Pace conduct" study is to evaluate implantation success, safety and outcome of pacing methods that maintain physiologic ventricular activation.