Cardiac Resynchronization Therapy Efficacy Enhancements

Study Overview
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Brief Summary
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The purpose of this study is to demonstrate that the amount of effective CRT (Cardiac Resynchronization Therapy) pacing during AF (atrial fibrillation) when CAFRPlus (Conducted AF Response Plus) is applied is not inferior to the amount of effective CRT pacing during AF when CAFR (Conducted AF Response) is applied.

Detailed Description
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The CRTee study is an IDE, prospective, multi-center, randomized, controlled, crossover clinical study, conducted worldwide and designed to demonstrate that the amount of effective CRT pacing during AF (atrial fibrillation) when CAFRPlus (Conducted AF Response Plus) is applied is not inferior to the amount of effective CRT pacing during AF when CAFR (Conducted AF Response) is applied. The study will be conducted at up to 30 centers located in the United States, Europe and Middle East and Africa (MEA).

Official Title
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Cardiac Resynchronization Therapy Efficacy Enhancements

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Device: Conducted AF Response (CAFR)
* Device: Conducted AF Response Plus (CAFRPlus)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is willing to sign and date the study patient Informed Consent form. Subject is at least 18 years of age (or older, if required by local law). Subject is expected to remain available after enrollment to complete follow-up visits in both arms of the study Subject has had a Medtronic Viva or Brava CRT-D device implanted at least 30 days prior to enrollment. Subject has history of AF burden, of at least 6 days of at least 4 hours of AF over any 4 week period within the last 90 days as documented in device diagnostic data OR if subject has no atrial lead (therefore no device diagnostic data) but clinical evidence of high AF burden. Subject has demonstrated history of being able to complete Left Ventricular Capture Management (LVCM) documented in device data. Subject has a documented % V pacing during AF of less than or equal to 97% within 90 days prior to enrollment or within 10 days after enrollment. Exclusion Criteria: Subject has undergone AV node ablation for treatment of AF. Subject has complete or 3rd degree AV block. Subject has had an MI within 30 days. Subject has medical conditions that limit study participation (per physician discretion). Subject is enrolled in one or more concurrent studies that could confound the study results as determined by Medtronic. Subject has a limited life expectancy for non-cardiac causes that would not allow completion of the study. Subject is pregnant (in the US, all women of child-bearing potential must undergo a pregnancy test within seven days prior to CRTee download). Subject meets the exclusion criteria required by local law.

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: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Group A: CAFR first<br>Subjects randomized to Group A will receive CAFR first, then cross over to CAFRPlus. | Device: Conducted AF Response (CAFR)<br>* The CAFR algorithm is currently available in the Medtronic market-released devices and intended to promote delivery of CRT pacing during conducted AT/AF episodes.<br>Device: Conducted AF Response Plus (CAFRPlus)<br>* The CAFRPlus algorithm is part of the CRTee feature set. This feature set has a diagnostic element that tracks the loss of effective CRT pacing that is occurring over time, both during normal sinus rhythm (NSR) and during AF. It also has an interventional element (i.e. CAFRPlus) that uses this evaluation of effective CRT pacing to adjust the pacing rate during AF to decrease loss of effective CRT pacing.<br>|
| Other: Group B: CAFRPlus first<br>Subjects randomized to Group B will receive CAFRPlus first, then cross over to CAFR. | Device: Conducted AF Response (CAFR)<br>* The CAFR algorithm is currently available in the Medtronic market-released devices and intended to promote delivery of CRT pacing during conducted AT/AF episodes.<br>Device: Conducted AF Response Plus (CAFRPlus)<br>* The CAFRPlus algorithm is part of the CRTee feature set. This feature set has a diagnostic element that tracks the loss of effective CRT pacing that is occurring over time, both during normal sinus rhythm (NSR) and during AF. It also has an interventional element (i.e. CAFRPlus) that uses this evaluation of effective CRT pacing to adjust the pacing rate during AF to decrease loss of effective CRT pacing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Effective CRT Pacing During AF (Non-inferiority Test) | The primary objective is to demonstrate that the percent effective CRT pacing during AF when CAFRPlus is applied is not inferior to when CAFR is applied (non-inferiority test). | Up to 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Effective CRT Pacing During AF (Superiority Test) | The secondary objective is to demonstrate that the percent effective CRT pacing during AF when CAFRPlus is applied is greater than when CAFR is applied (superiority test). | Up to 4 months |