Efficacy of the CMI Magnetocardiograph in Diagnosing Acute Coronary Syndromes in Patients Presenting With High Risk Unstable Angina.

Efficacy of the CMI Magnetocardiograph in Diagnosing Acute Coronary Syndromes in Patients Presenting With High Risk Unstable Angina as Defined by ACC/AHA Guidelines

A magnetocardiograph (MCG) is a device capable of recording of magnetic fields arising from the electrical activity of the heart with traces similar to an electrocardiogram (ECG). This system was developed as a noninvasive, non-contact diagnostics of obstructive coronary artery disease (CAD), and especially of lack of oxygen in the heart as in a heart attack. The overall objective of this study is to demonstrate the efficacy of this MCG device for the detection and diagnosis of lack of oxygen of the heart in patients with chest pain.

Study Overview

• Status: Completed
• Conditions: Myocardial Ischemia
• Intervention / Treatment: Device: Magnetocardiograph

Detailed Description

Coronary Artery Disease is the leading cause of death in the United States. The non invasive detection of Acute Coronary Syndromes (ACS's) remains a clinical challenge. Electrocardiogram (ECG) may only diagnose myocardial infarction in 50 % of the cases. Magnetocardiography is a new and noninvasive method capable of measuring and mapping the magnetic field that is generated during the cardiac cycle. The electric current is affected by ischemic damage, which in turn alters the magnetic field. The magnetic field is not affected by body tissues, unlike the surface current measurements in ECG.

Comparisons: The diagnostic accuracy of the CMI-Magnetocardiograph will be compared to that of the ECG in diagnosing High Risk Unstable Angina.

• Study Type: Observational
• Enrollment (Actual): 137

Contacts and Locations

Study Locations

• United States
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

*ACC/AHA Guidelines for Unstable Angina: High Risk (≥1 of the following)

History

• Accelerating tempo of ischemic symptoms in the last 48 hrs Pain
• Prolonged, ongoing (>20 min) rest pain (resistant to treatment) Clinical findings
• Pulmonary edema
• New / ↑ MR murmur
• S3 or new/ ↑ rales
• Hypotension, brady -/tachycardia - Age>75y ECG
• Angina at rest with transient ST changes >0.05 mV
• New (L)BBB
• Sustained VT Cardiac Markers
• Markedly elevated troponin

Patients classified as having high-risk unstable angina at presentation in the ED will be approached for enrollment in the study.

Description

Inclusion criteria:

• Patients classified as having High Risk Unstable Angina according to the ACCIAHA guidelines.
• Age ≥ 18 years.

Exclusion criteria:

• Hemodynamically unstable patients.
• Patients who just prior to or just after admission exhibit tachycardia with heart rates exceeding 150 bpm.
• Patients with third degree AV Block.
• Patients with pacemakers or internal cardiac defibrillators.
• Patients who cannot lie in a supine position for the MCG examination.
• Patients who refuse entry into the registry

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
1. Determine the discriminatory ability of the scores derived from the MCG evaluation to discriminate between patients with versus without a clinical diagnosis of ACS at discharge.	1 year
2. Compare the discriminatory ability of scores derived from the MCG, the troponin level, and the ECG results, separately or in combination, to discriminate between patients with without a diagnosis of ACS at discharge.	1 year

Secondary Outcome Measures

Outcome Measure	Time Frame
1. Evaluate the sensitivity of the MCG to detect an ultimate diagnosis of ACS, MI, CHF, or death at 1 month, 6 months, and 1 year following discharge.	1 year

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Collaborators: CardioMag Imaging
• Investigators: Principal Investigator: Peter A. Smars, M.D. EM, Mayo Clinic

Study record dates

Study Major Dates

• Study Start: August 1, 2004
• Primary Completion (Actual): February 1, 2008
• Study Completion (Actual): February 1, 2008

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 12, 2005
• First Posted (Estimate): September 15, 2005

Study Record Updates

• Last Update Posted (Estimate): July 18, 2011
• Last Update Submitted That Met QC Criteria: July 15, 2011
• Last Verified: July 1, 2011

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Pain; Neurologic Manifestations; Chest Pain; Angina Pectoris; Myocardial Ischemia; Ischemia; Acute Coronary Syndrome; Angina, Unstable
• Other Study ID Numbers: 738-04