Adaptive CRT Effect on Electrical Dyssynchrony

Not Applicable

Completed

Interventions: Device: Adaptive cardiac resynchronization therapy
Device: Conventional Cardiac Resynchronization Therapy

Brief Summary: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
aCRT On	Adaptive cardiac resynchronization therapy	The adaptive CRT algorithm will be turned on for the CRT device implanted in the patients in this arm.
aCRT Off	Conventional Cardiac Resynchronization Therapy	The adaptive CRT algorithm will be turned off for the CRT device implanted in the patients in this arm.

Primary Outcome Measures

Name	Time	Method
Change in Ventricular Electrical Uncoupling (VEU), Calculated as the Difference in Difference Between the Mean Left Ventricular (LV) and Right Ventricular (RV) Activation Times.	baseline and 6 months after device implantation	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.

Secondary Outcome Measures

Name	Time	Method
Change in 6-minute Walk Distance 6 Months Post CRT	baseline and 6 months after device implantation	Change in 6-minute walk distance 6 months post CRT as compared to baseline
Change in MLHFQ Total Score	baseline and 6 months after device implantation	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).