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NCT Number: NCT04221763

Mechanisms and Innovations in Cardiac Resynchronisation Therapy

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.

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Key information

Conditions

Heart Failure Arrhythmias, Cardiac Bundle-Branch Block Cardiac Conduction System Disease Cardiovascular Diseases Heart Block Heart Diseases Left Bundle-Branch Block Left Ventricular Systolic Dysfunction Non-Specific Intraventricular Conduction Defect Pathologic Processes Pathological Conditions, Signs and Symptoms Right Bundle-Branch Block Ventricular Dysfunction Ventricular Dysfunction, Left

Age range

18 year–100 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hammersmith Hospital Imperial College NHS trust

London, W12 0HS, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

His-bundle pacing.

Device

Cardiac resynchronisation therapy can be achieved using biventricular pacing involving placement of three leads into the right atrium, right ventricle and coronary sinus (epicardial left ventricle). Alternatively the third lead may be placed at the bundle of His or left ventricular septum to pace the left bundle directly.

Other names: Left bundle pacing, Biventricular pacing, Combined His-bundle and left ventricular epicardial pacing (HOT-CRT)

Primary outcomes

  1. Acute change is systolic blood pressure

    Time frame: 20 minutes

    Mean change in systolic blood pressure (mmHg) from atrial pacing to AV sequential CRT pacing (HBP, LBP, epiBVP and combined HPB with epiLVP) at optimal AV delay measured in mmHg.

  2. Acute electrical measurements

    Time frame: 20 minutes

    Mean change in left ventricular activation time (Milliseconds) (measured using ECGI) during AV sequential CRT pacing (HBP, LBP, epiBVP and combined HPB with epiLVP) at optimal AV delay measured in Milliseconds.

Secondary outcomes

  1. Conduction system battery longevity

    Time frame: 6 weeks, 3 months, 6 months, 12 months.

    The measurements include battery longevity measured in months.

  2. Conduction system lead threshold

    Time frame: 6 weeks, 3 months, 6 months, 12 months.

    The measurements include lead threshold to achieved QRS narrowing measured in Volts at 0.5ms and 1ms.

  3. Heart failure symptoms

    Time frame: 6 months

    Heart failure symptoms of patients with permanent conduction system leads will be assessed at follow up at 3 month, 6 months and 12 months. The symptoms will be assessed using the Minnesota living with heart failure questionnaire score.

  4. Left ventricular ejection fraction

    Time frame: 12 months

    Patients with permanent conduction system leads will undergo a repeat echocardiography and measure their left ventricular ejection fraction.

  5. Cardiopulmonary exercise testing

    Time frame: 6 months

    Patients with permanent conduction system leads will undergo symptom assessment with a repeat cardio-pulmonary exercise test to measure MVO2 in litres/minute.

Sponsors and collaborators

Lead sponsor

Imperial College London

Other

Registry information

Official study title

Evaluation of Mechanisms and Innovations in Cardiac Resynchronization Therapy

Acronym: MIC

Important dates

Study start
2019
Primary completion
2022
Study completion
2022
First posted
Jan 9, 2020
Registry last updated
Mar 22, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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