Adaptive CRT Effect on Electrical Dyssynchrony

Study Overview
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Brief Summary
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The purpose of this study is to better understand how adaptive cardiac resynchronization therapy (aCRT) might benefit patients. aCRT works by sometimes giving stimulation to only the left side of the heart, rather than to both sides, depending on how it senses the heart is functioning. CRT without the adaptive algorithm works by giving stimulation to both sides of the heart. aCRT has already been approved by the FDA and is being used in patients now, but it is not clear which patients it should be used in compared to normal CRT. This study will include patients who are already scheduled to get a CRT device. The investigators will then randomize patients to the aCRT study arm or to the CRT study arm. After 6 months, the investigators will assess the electrical activity of the patients' hearts. After this time, the patient and their doctors will be able to decide if they would like to change the type CRT they have been designated.

Official Title
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Adaptive CRT Effect on Electrical Dyssynchrony

Conditions
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Cardiomyopathy, Heart Failure, Left Bundle Branch Block

Intervention / Treatment
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* Device: Adaptive cardiac resynchronization therapy
* Device: Conventional Cardiac Resynchronization Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient has a standard class I or class II indications for CRT-P or CRT-D implantation in accordance with ACC/AHA/HRS guidelines (2012 ACCF/AHA/HRS Focused Update Incorporated Into the ACCF/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities)2.At least 18 years of age at the time of consent Is willing and able to comply with the protocol Exclusion Criteria: Chronic atrial arrhythmias defined as: Atrial fibrillation is permanent when it has resisted all attempts to restore sinus rhythm or when the physician and patient decide that no such attempt should be made. Patient has ever had a previous or has an existing CRT system, ICD, or pacemaker. GFR <30ml/min Patient has had unstable angina, acute myocardial infarction, coronary artery bypass graft surgery, or percutaneous transluminal coronary angioplasty within 30 days prior to study enrollment Patient has primary valvular disease and is indicated for valve repair or replacement Patient is enrolled in ≥1 concurrent studies that would confound the study results (any other interventional trial) Patient is pregnant or of childbearing potential and not on a reliable form of birth control. All women of child-bearing potential must undergo a pregnancy test. Patient status post heart transplant Patient has been classified as NYHA functional class IV within 3 months prior to study enrollment concomitant conditions other than cardiac diseases that were associated with a higher likelihood of death during 1 year after enrollment Patient, legal guardian or authorized representative is unable or unwilling to cooperate or give written informed consent

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: aCRT Off<br>The adaptive CRT algorithm will be turned off for the CRT device implanted in the patients in this arm. | Device: Conventional Cardiac Resynchronization Therapy<br>* CRT without the adaptive algorithm works by giving stimulation to both sides of the heart.<br>* Other names: CRT;|
| Experimental: aCRT On<br>The adaptive CRT algorithm will be turned on for the CRT device implanted in the patients in this arm. | Device: Adaptive cardiac resynchronization therapy<br>* The adaptive cardiac resynchronization therapy (aCRT) algorithm works by sometimes giving stimulation to only the left side of the heart, rather than to both sides, depending on how it senses the heart is functioning.<br>* Other names: aCRT;|
| No Intervention: Registry arm<br>Participants who are not eligible for the randomization because of the implantation of the device that is not capable of delivering aCRT. The team of clinical care providers makes such a clinical decision acting in the patient's best interests. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Ventricular Electrical Uncoupling (VEU), Calculated as the Difference in Difference Between the Mean Left Ventricular (LV) and Right Ventricular (RV) Activation Times. | LV and RV activation time values were measured on reconstructed epicardial activation maps at baseline and 6 months post-CRT. Positive VEU indicated LV uncoupling (delay) from the RV, whereas negative VEU indicated RV uncoupling (delay) from the LV. Difference in difference (change in VEU from baseline to 6 months post-CRT) is reported as the primary outcome. | baseline and 6 months after device implantation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in 6-minute Walk Distance 6 Months Post CRT | Change in 6-minute walk distance 6 months post CRT as compared to baseline | baseline and 6 months after device implantation | 
| Change in MLHFQ Total Score | Change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) total score 6 months post-CRT as compared to baseline. The total MLHFQ score range from 0 (zero; the best health) to 105 (the worst health). Higher MLHFQ values represent worse health. Negative values of the change in total MLHFQ score mean the total MLHFQ score decreased six months after device implantation compared to baseline (improvement). | baseline and 6 months after device implantation |