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Revo MRI

Pacemaker

Clinical Studies and Outcomes

Preclinical research and a multicenter, randomized, controlled clinical trial demonstrate the safety and efficacy of Revo MRI™ Pacing System when used according to specified conditions.

Espandi tutto

MRI

Preclinical Research and Clinical Trial

Extensive preclinical evaluation was conducted with clinically relevant and worst-case MRI scan conditions. Analysis was based on:

  • Bench (in vitro) testing
  • Animal (in vivo) testing
  • Computer simulations
Parameter Evaluation

MRI-Induced Case Heating

In vitro evaluation at maximum labeling conditions and worst-case MRI scan positions demonstrated an overall peak case temperature increase of 5.8°C. When the thermal dose is expressed in terms of CEM 43°C (Cumulative Equivalent Minutes at 43°C), this yields 4.1 minutes at 43°C, significantly below the 60 CEM 43°C upper limit.

The largest measured force was approximately 25% of the established upper limit, while the largest measured torque was about 65% of the established upper limit.

MRI-Induced Vibration

In vitro testing for a total of 1,475 device-hours at clinically relevant and worst-case MRI scan conditions demonstrated no missing pacing pulses during testing and proper operation following testing, without resets or battery replacement indications.

MRI-Induced Lead Heating

Simulations predicting the probability for pacing capture threshold change (the most sensitive and relevant measure of lead tip heating) showed the probability of a 0.5 V MRI-induced change in pacing capture threshold is ≈ 1 / 71,000 and that of a 1.0 V MRI-induced change is ≈ 1 / 2,900,000.

MRI-Induced Unintended Cardiac Stimulation (UCS)

Analysis combined a prediction for the induced voltage pulse widths and amplitudes and an in vivo canine study to evaluate the stimulation threshold to these pulses. Results confirmed that patient risk from UCS is at an acceptable level.

MRI-Induced Device Interactions

During bench testing, Revo MRI SureScan Pacing System delivered appropriate therapy during an MRI. MRI exposure did not compromise device operation, pacemaker reliability, or longevity.

Confirmatory Clinical Trial*

crdm-9-bth

A multicenter, randomized, controlled clinical trial was designed to evaluate the safety of the Revo MRI SureScan Pacing System when used per the conditions specified in the labeling.

Study Design

  • Multicenter, randomized, controlled clinical trial designed to evaluate:
    • Safety
    • MRI-related complications
    • Pacing capture thresholds and sensing amplitude
  • 464 patients received a Revo MRI SureScan Pacing System
  • Patients randomized to elective MRI or no MRI, approximately 9-12 weeks post-implant
  • MRI imaging intended to represent commonly used, clinically relevant scans

Key Results

  • 100% free of MRI-related complications (n = 211, P < 0.001)
  • No sustained atrial or ventricular arrhythmias, no asystole, no pacemaker output inhibition, and no electrical resets in the group receiving MRIs
  • Minimal changes in pacing capture thresholds

Footnotes

*

This study is also referred to as the EnRhythm MRI Pacing System Clinical Study.

AF Management