Magnetocardiography (MCG) in Subjects Undergoing CT Angiography (CTA)

NCT ID: NCT00574561

Last Updated: 2009-11-17

Basic Information

• Recruitment Status: WITHDRAWN
• Total Enrollment: 300 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2007-07-31
• Study Completion Date: 2009-12-31

Brief Summary

The investigators wish to study the magnetic field map using magnetocardiography (MCG) in subjects undergoing computed tomographic angiography (visualization of the heart arteries using CT scanning, CTA). The main purposes is to investigate if MCG is capable of detecting the presence of obstructive coronary artery disease (CAD) as detected by CT angiography (CTA) as well if the MCG can exclude the presence of CAD as defined by CTA.

Secondarily the investigators will look at the correlation of MCG with non-obstructive CAD and the correlation of MCG with other tests (treadmill testing, stress echo or nuclear scan, coronary angiography) done as part of the work up for CAD.

Detailed Description

Cardiomagnetism refers to the detection, analysis and interpretation of the magnetic fields generated by the electrical activity of the heart. The peak value of the magnetic fields of the heart is more than a million times smaller than the Earth's magnetic field. A major breakthrough in the capability of measuring such small fields came with the invention of the SQUID (superconducting quantum interference device) in the late sixties. The first magnetocardiograms (MCGs) measured with the SQUID were recorded by Cohen et al. in 1970. These earlier measurements were performed in very expensive magnetically shielded rooms, initially utilizing only one or two SQUID probes. In the eighties this technology was tested in several laboratories creating a magnetic field map by moving one SQUID sequentially above the chest to create an image of the whole hearts magnetic field. These maps were then attempted correlated with various pathologies (1).

Since then the technology has been greatly improved and several multi-channel machines are in use across the world for research purpose for arrhythmia localization and ischemia detection. However, at present time, only one company (CardioMag Imaging, Schenectady, New York) has developed a machine that operates outside a shielded room.

The CardiomagImaging (CMI) Magnetocardiograph (MCG) is capable of noninvasive recording of magnetic fields arising from the electrical activity of the heart with very high spatial and temporal resolution. The temporal trace of the MCG is analogous to an ECG, and, similarly, can be recorded in multiple leads. This MCG device has been specifically developed for the general purpose (outside shielded room) of non-contact, non-invasive diagnostics of ischemia.

The CMI MCG device has been approved by the FDA as a safe tool to measure and record the magnetic field arising from the heart's electrical currents. It is awaiting FDA approval for the specific diagnosis of ischemia in chest pain patients (2,3).

We have been using the CMI 9-channel MCG for detection of ischemia in patients admitted to Cedars-Sinai Medical Center for acute chest pain syndrome. The results are very exciting and have been published in abstracts and one manuscript, with another manuscript in submission (4,5). In summary, we studied 75 patients with acute chest pain and 65 healthy volunteers and found a very strong association with an abnormal MCG scan and ischemia (p<0.0001). The sensitivity, specificity, PPV and NPV was 87.1%, 85.7%, 64.3%, and 95.7%, respectively. In comparison, the diagnostic value of the stress SPECT imaging was 91.3%, 75.0%, 75.0%, and 91.3%, for sensitivity, specificity, positive and negative predictive value, respectively. These results were achieved without the use of stress provocation, contrast administration, or any ionizing radiation, and the results were available immediately.

Since starting the chest pain protocol another diagnostic imaging technology has become more widespread used, 64-slice CT angiography. This technology utilizes a fast CT scanner and involves administration of a contrast agent, but avoids the invasiveness of a heart catheterization. The accuracy of detection of CAD and its exclusion is very high as compared with angiography (6). Although minimally invasive, the CT angiogram does involve a radiation dose similar to that used with stress nuclear testing, approximately 900 to 1100 mrem (6) and the iodine contrast used may cause contrast nephropathy, especially in diabetics and those with already impaired renal function. The use of this technology provides an opportunity to find subjects with normal coronary arteries with accuracy close to as high as for invasive coronary angiography. To date, this population has been hard to study, since subjects with a normal stress test rarely will undergo more invasive studies.

Therefore, we wish to conduct this correlative study with CT angiography and the entirely noninvasive and risk free MCG to see if we in the future may be able to avoid some of the risks associated with CTA. We think that we may find that subjects with a clearly abnormal MCG may not need CTA, but could proceed directly to angiography and possible angioplasty.

Conditions

Chest Pain

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: PROSPECTIVE

Eligibility Criteria

Inclusion Criteria

• Subjects undergoing 64-slice CT angiography

Exclusion Criteria

• Hemodynamically unstable patients
• Patients with pacemakers or internal defibrillators
• Minors < 18 years of age
• Patients unable to lie flat for the examination

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

CardioMag Imaging

INDUSTRY

Sponsor Role: collaborator

Cedars-Sinai Medical Center

OTHER

Sponsor Role: lead

Responsible Party

Cedars-Sinai Medical Center

Principal Investigators

Kirsten Tolstrup, MD

Role: PRINCIPAL_INVESTIGATOR

Cedars-Sinai Medical Center

Locations

Cedars-Sinai Medical Center

Los Angeles, California, United States

Countries

United States

References

1)Stroink G, MacAuley C, Montague TJ, Horacek BM. Normal and abnormal components in magnetocardiographic maps of a subject with myocardial infarction. Med. Biol. Eng. Comp. 1985, 23, 61-62.

Reference Type: BACKGROUND

Koch H. Recent advances in magnetocardiography. J Electrocardiol. 2004;37 Suppl:117-22. doi: 10.1016/j.jelectrocard.2004.08.035.

Reference Type: BACKGROUND

PMID: 15534820 (View on PubMed)

Fenici R, Brisinda D, Meloni AM. Clinical application of magnetocardiography. Expert Rev Mol Diagn. 2005 May;5(3):291-313. doi: 10.1586/14737159.5.3.291.

Reference Type: BACKGROUND

PMID: 15934809 (View on PubMed)

4)Tolstrup K, Madsen B, et al. Resting Magnetocardiography Accurately Detects Myocardial Ischemia in Chest Pain Patients with normal or non-specific ECG Findings. Cardiology. 2006;106:270-276.

Reference Type: BACKGROUND

5)Kirsten Tolstrup, Donatella Brisinda, Anna M. Meloni, Brian Cheung, Sean Rashti, Robert J. Siegel, Riccardo Fenici. Resting Magnetocardiography is Highly Accurate for the Detection of Ischemia in Patients with Acute Chest Pain Syndrome. Submitted.

Reference Type: BACKGROUND

Stein PD, Beemath A, Kayali F, Skaf E, Sanchez J, Olson RE. Multidetector computed tomography for the diagnosis of coronary artery disease: a systematic review. Am J Med. 2006 Mar;119(3):203-16. doi: 10.1016/j.amjmed.2005.06.071.

Reference Type: BACKGROUND

PMID: 16490463 (View on PubMed)

Other Identifiers

10057

Identifier Type: -

Identifier Source: org_study_id