At ACEP 2021, Drs. Sharon Mace and Claire Pearson presented Detection of Acute Coronary Syndrome by Magnetocardiography.
This presentation highlighted a very novel, unique, and promising approach to evaluating patients with cardiac risk factors who present to the ED with chest pain or other anginal equivalents. As many ER physicians can attest, it is often difficult to determine if the etiology is cardiac in nature or not. Low-risk and non-cardiac presentations are easily sent home, while patients with high-risk with classic or concerning symptoms are placed on drips and admitted. A large majority of patients, however, present in that intermediate range, and the disposition is often one of a conservative nature where a patient is placed in observation status or a CDU and additional diagnostic testing and/or consults are obtained. This has been the standard of care and is appropriate until we can more safely rule-out or rule-in cardiac etiology.
This particular presentation was preceded by others during the research forum highlighting cardiovascular topics including utility of HEART, TIMI, EDACS scores, and use of cardiac-biomarkers with emphasis placed on hsTn. Additionally, the utility of diagnostic Cardiac CTA in the ED setting was discussed. While each of these approaches had some undeniable benefits, inherent challenges appeared to limit the utility in most emergency department settings. The unmet clinical need was an accurate, sensitive, specific, and safe rapid diagnostic test.
The speaker presented an interim analysis of a multicenter study being performed at the Cleveland Clinic, Wake Forest, and Ascension St John Detroit, using cardiac magnetocardiography. The authors analyzed 99 patients with a mean HEART score of 4.1. Using an array of 36 magnetic sensors to analyze the magnetic field maps generated from the patients’ heart, machine learning algorithms were able to identify ischemic changes that result from patients with acute coronary syndrome. The MCG was able to correctly identify 90.1% (10/11) of patients that had a positive coronary angiogram (CA) and 100% (6/6) that had a negative CA. By comparison, 33% of these patients with a negative CA had negative hsTn (1/3) and 66% of positive CA patients had positive hsTn (2/3). MCG had a higher sensitivity, specificity, PPV, NPV, and accuracy than the HEART score or serial troponins (both conventional and hsTn). The emphasis beyond these statistics was the ability to perform this test in a very safe and timely manner by a tech in less than five minutes, with therefore the ability to avoid non-invasive stress testing, contrast, radiation or radioisotope material, and the avoidance of an unnecessary observation stay. With many of our ER and hospitals overcrowded, LOS was reduced from 8.7 hours to 4 hours. Differences in cost were not specifically discussed but would be a very interesting addition to the analysis.
Dr. Takla is a part-time consultant/employee of Genetesis, is on Janssen's speaker's bureau, and is part of Alexion's speaker's bureau.
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