Safety of Cardiac Pacemakers in 1.5T Tesla MRI

Heart Diseases Clinical Trial

Official title:

Studie Zur Sicherheit Von Medtronic Schrittmachern Bei Magnetresonanz-Bildgebungsverfahren an 1,5 Tesla-Systemen Study to Evaluate Safety Medtronic Pacemakers in MR Imaging at 1.5T Tesla)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00336011
• Other study ID #: 186/02
• Status: Completed
• Phase: N/A
• First received: June 9, 2006
• Last updated: June 9, 2006
• Start date: December 2002
• Est. completion date: January 2006

Study information

• Verified date: January 2006
• Source: University Hospital, Bonn
• Contact: n/a
• Is FDA regulated: No
• Health authority: Germany: Federal Institute for Drugs and Medical Devices
• Study type: Observational

Clinical Trial Summary

To evaluate short-term and long-term effects by MR imaging on the technical and functional status of Medtronic pacemakers.

Description:

The presence of a cardiac pacemaker (PM) is currently considered an absolute contraindication to MR imaging, and most patients with PM are excluded from having MRI. In 2002 there were approximately 2.4 million patients in the US with cardiac PM, and this number is growing by 80,000 annually. A previous study has shown that MRI is indicated in 17% of all patients with pacemakers within 12 months of device placement 1, demonstrating the need for a practical and safe approach for performing MRI on PM patients.

The aim of this study is to develop a strategy for safe performance of MR imaging at 1.5T, which included exclusion of pacemaker dependent patients and those requiring imaging of the thorax, restriction of specific absorption rate (SAR) values to minimize the risk of lead heating, and PM reprogramming to avoid interference from time varying gradient fields. The safety of this approach is then evaluated in a large group of PM patients including assessment of potential myocardial thermal injury by measuring serum troponin I and pacing capture thresholds, and performing a 3-month follow-up to evaluate long-term effects.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 75
• Est. completion date: January 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• Urgent need for an MRI examination

• Presence of a Medtronic PM system manufactured between 1993 and 2004

• Stable pacemaker physical parameters

• Battery voltage > 2.7 V

• Battery impedance < 2000 Ohm

• Battery estimated remaining lifetime > 6 months

• Lead impedances 200-2000 Ohm

• Stable pacing parameters

• Pacing capture threshold <2.5V at a pulse duration of 0.4ms

• Sensing > 5mV

• Minimum 3 months since pacemaker and lead implantation

Exclusion Criteria:

• PM system manufacturer other than Medtronic

• History of ventricular tachycardia (VT) or ventricular fibrillation

• Unstable angina

• Myocardial infarction within the previous 3 months

• Cardiothoracic surgery within the previous 3 months

• Complete atrioventricular block

• Absolute pacemaker dependence

• Heart rate < 40 bpm or

• Heart rate < 60 bpm producing neurological symptoms

• Presence of an abdominal pacemaker with lead length > 70 cm

• Presence of MRI incompatible bioimplants or other MRI incompatible materials

• Request for an MR examination of the chest, including the heart, breasts and thoracic spine

Study Design

Observational Model: Defined Population, Time Perspective: Longitudinal

Related Conditions & MeSH terms

• Heart Diseases

Intervention

Device:
• Magnetic resonance imaging

Locations

Country	Name	City	State
Germany	University of Bonn, Department of Radiology	Bonn	NRW

Sponsors (2)

Lead Sponsor	Collaborator
University Hospital, Bonn	Medtronic

Country where clinical trial is conducted

Germany,