ProMRI Study of the Iforia ICD System (Phase C)

Study Overview
=================
Brief Summary
-----------------
The objective of the ProMRI Study is to demonstrate the clinical safety of the ProMRI ICD System when used under specific MRI conditions.

Official Title
-----------------
ProMRI Study of the Iforia ICD System (Phase C)

Conditions
-----------------
Implantable Cardioverter-Defibrillator With Magnetic Resonance Imaging

Intervention / Treatment
-----------------
* Device: Patients with a ProMRI ICD System
* Other: Magnetic Resonance Imaging (MRI) scan


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: The following initial inclusion criteria must be met for a subject to be enrolled and considered for the MRI-procedure: Age greater than or equal to 18 years Able and willing to complete MRI testing Able to provide written informed consent Available for follow-up visit at the study site Implanted with an ICD System consisting only of an Iforia DR-T and Linoxsmart S 65 / Linoxsmart SD 65/18 with Setrox S 53 atrial lead or Iforia VR-T DX and Linoxsmart S DX 65/15 or Linoxsmart S DX 65/17. ICD implanted pectorally All ICD system components implanted, repositioned, or exchanged at least 5 weeks prior to enrollment Underlying rhythm identifiable during sensing test All pacing thresholds are measureable and are less than or equal to 2.0 V @ 0.4 ms (Criterion does not apply to atrial pacing threshold for subjects with an Iforia DR-T that have AF and are permanently programmed to VVI and for subjects with an Iforia VR-T DX) Ventricular sensing is measurable and >6.5mV Absence of phrenic nerve stimulation at 5.0V and 1.0 ms Pacing impedance is between 200 and 1500 ohm Shock Impedance is between 30 and 90 ohm Able and willing to use the CardioMessenger II At the pre-MRI procedure, the following procedure-related criteria must be met for the subject to undergo the MRI scan: Absence of phrenic nerve stimulation at 5.0V @ 1.0 ms |pacing threshold at Pre-MRI follow-up - pacing threshold at baseline| ≤ 0.5 V (ICD Lead Only) All pacing thresholds are measureable and are less than or equal to 2.0 V @ 0.4 ms (Criterion does not apply to atrial pacing threshold for subjects with an Iforia DR-T that have AF and are permanently programmed to VVI and for subjects with an Iforia VR-T DX.) Ventricular sensing is measurable and >6.5mV The ICD system has been implanted for at least six weeks. Subject did not have an ICD or lead explant, exchange or reposition in the previous 6 weeks. All lead pacing impedances are between 200 and 1500 ohm Shock impedance is between 30 and 90 ohm Battery status is at least 30% of capacity

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ICD System Therapy<br>Patients with a ProMRI ICD System | Device: Patients with a ProMRI ICD System<br>* Tachycardia Fast Heart Beat<br>Other: Magnetic Resonance Imaging (MRI) scan<br>* MRI scan of heart/chest or thoracic spine<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MRI and ICD System Related Serious Adverse Device Effect (SADE) Free Rate |  | 1 Month Post-MRI | 
| Percentage of Participants Free of Ventricular Pacing Threshold Rise | Evaluate the percentage of ICD leads free of ventricular pacing threshold increase between the Pre-MRI and one-month post-MRI follow-up. | Between Pre-MRI and 1 Month Post-MRI | 
| Percentage of Participants Free of R-wave Sensing Attenuation | Evaluate the percentage of subjects free of R-wave attenuation between the Pre-MRI and one-month post-MRI follow-up. | Between Pre-MRI and 1 Month Post-MRI |