Non-Invasive Method for Evaluation of Cardiac Resynchronization Therapy

Study Overview
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Brief Summary
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Left bundle branch block (LBBB) exists in about 25% of patients with congestive heart failure and is associated with worsened prognosis. Cardiac resynchronization therapy (CRT) has been one of the most important advancements in the past two decades for patients with LBBB heart failure. However, 30-40% of patients receiving a CRT do not benefit from it. In this study, the investigators will test a noninvasive device to evaluate acute effect of CRT during implantation and at follow-up CRT controls. In addition, echocardiography will be performed during CRT turned ON and OFF to visualize the changes in intraventricular flow and functional parameters of the heart.

Official Title
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Non-Invasive Method for Evaluation of Cardiac Resynchronization Therapy

Conditions
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Heart Failure, Pacemaker DDD, Cardiomyopathies, Heart Diseases, Cardiovascular Diseases

Intervention / Treatment
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* Device: Cardiac Resynchronization Therapy (CRT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients referred for CRT implantation or postoperative control at Oslo University Hospital based on the European Society of Cardiology (ESC) guidelines (2021), and criteria below: Sinus rhythm. New York Heart Association class II / III heart failure on diagnosis and on optimal medical therapy. Left bundle branch block. QRS duration ≥ 130 ms. Left ventricular ejection fraction ≤ 40%. Patients must have echocardiography examination before implantation Informed consent obtained from the patient. Exclusion Criteria: Age < 18 years and > 80 years; Ongoing atrial fibrillation; Complete atrioventricular block

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1 - Implantation<br>Patients admitted for CRT implantation according to current ESC/AHA guidelines | Device: Cardiac Resynchronization Therapy (CRT)<br>* Cardiac resynchronization therapy (CRT) is a modality of cardiac pacing used in patients with left ventricular (LV) systolic dysfunction and dyssynchronous ventricular activation that provides simultaneous or nearly simultaneous electrical activation of the LV and right ventricle (RV) via stimulation of the LV and RV (biventricular pacing) or LV alone.<br>|
| Group 2 - 6 months control<br>Patients admitted for 6 months routine checkups of their CRT devices | Device: Cardiac Resynchronization Therapy (CRT)<br>* Cardiac resynchronization therapy (CRT) is a modality of cardiac pacing used in patients with left ventricular (LV) systolic dysfunction and dyssynchronous ventricular activation that provides simultaneous or nearly simultaneous electrical activation of the LV and right ventricle (RV) via stimulation of the LV and RV (biventricular pacing) or LV alone.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reverse remodelling at 6 months follow-up | Measured by left ventricular end-systolic volume reduction of at least 15% assessed by echocardiography | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hospitalization | all cause hospitalization heart failure hospitalization defined by symptom, signs and biochemistry (NT-proBNP) | 2 years | 
| Mortality | all cause death sudden cardiac death cardiovascular death transplantation | 2 years | 
| New York Heart Association (NYHA) Functional Classification | The New York Heart Association (NYHA) functional classification provides a simple way of classifying the extent of heart failure. It places patients in one of four categories based on how much they are limited during physical activity; the limitations/symptoms are in regard to normal breathing and varying degrees in shortness of breath and/or angina. | 2 years | 
| Minnesota Living with Heart Failure Questionnaire | Minnesota living with heart failure questionnaire is a validated patient-oriented measure of the adverse effects of heart failure on a patient's life. | 2 years | 
| Packer clinical composite score | The Packer clinical composite score classifies each patient into 1 of 3 categories (improved, worsened, unchanged), and is determined using clinical outcomes (hospitalizations, death, heart transplant), heart failure status, and patient symptoms (defined by a higher New York Heart Association (NYHA) functional classification and quality of life measured using the Minnesota Living With Heart Failure Questionnaire). Each endpoint will be assessed at 6, 12, 18, and 24 months. | 2 years | 
| 6 minute walk test | The 6 minute walk test is a sub-maximal exercise test used to assess aerobic capacity and endurance. The distance covered over a time of 6 minutes is used as the outcome by which to compare changes in performance capacity. The test will be performed in group 1 before implantation and at 6 months control to evaluate response to intervention. | 6 months |