Mechanisms and Innovations in Cardiac Resynchronisation Therapy (MIC)

Imperial College London

Status: Completed

Conditions: Non-Specific Intraventricular Conduction Defect; Left Bundle-Branch Block; Left Ventricular Systolic Dysfunction; Right Bundle-Branch Block; Heart Failure

Treatments: Device: His-bundle pacing.

Study type: Interventional

Funder types: Other

Identifiers

NCT04221763

18HH4801

FS/19/4/34013 (Other Grant/Funding Number)

Details and patient eligibility

About

The aim of this study is to compare the effectiveness of multiple modalities of cardiac resynchronisation therapy using high precision acute electrical and haemodynamic measurements.These modalities include biventricular pacing and conduction system pacing utilising His bundle and left bundle pacing. Conduction system pacing is a more physiological form of pacing. The study hypothesises that this will produce more effective cardiac resynchronisation.

Full description

This is a single centre acute electrical/haemodynamic and observational study of a subgroup of patients with heart failure. A total of 60 will be recruited. The acute study involves within patient comparison of biventricular and conduction system pacing using detailed electrical mapping and high precision haemodynamic measurement protocol.

Participants will have permanent conduction system pacing if;

• Baseline left bundle branch block and QRS > 140ms or QRS >150ms and any QRS morphology AND
• Conduction system pacing is successful at reducing QRS duration by 20ms or more with satisfactory pacing parameters.

Participants who receive permanent conduction system pacing will have follow up at 6 weeks, 3 months, 6 months and 12 months. Non-invasive markers including mechanical activation pattern (echocardiography and cardiac MRI) and electrical activation pattern (ultra-high frequency electrocardiography) will be used to identify the characteristics of patients who benefit from conduction system pacing.

Enrollment: 47 patients

Sex: All

Ages: 18 to 100 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients referred for conventional CRT
• Severe heart failure (LVEF, a measure of heart pumping, < 35% - severe)
• Prolonged QRS duration (>120ms)
• Adults willing to take part (age > 18 years)
• Able to give consent

Exclusion criteria

• Unable to give consent
• Children (age < 18 years)
• Pregnant women

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

---

47 participants in 1 patient group

Heart failure and abnormal cardiac conduction

Experimental group

Description:

Subjects will have an attempt at His-bundle pacing, left bundle pacing and biventricular pacing. Pacing at the His bundle and the left bundle will be attempted using a Medtronic SelectSecure™, Model 3830 lead. Delivery of the lead utilizes a deflectable sheath, the Medtronic SelectSite™, Model C304. Biventricular pacing will utilise a left ventricular lead placed in the coronary sinus using any of the 5 manufactures of CS leads Biotronik, Boston Scientific, Medtronic, Sorin, and St. Jude Medical or in participants receiving permanent conduction system pacing left ventricular pacing will be achieved using a Cordis ATW™ wire placed in the coronary sinus.

Treatment:

Device: His-bundle pacing.