Cardiac Magnetic Resonance Improves Diagnosis in Cardiac Arrest Survivors

In a retrospective study published in Resuscitation, researchers from the University of Padua in Italy and the University of Bristol in the United Kingdom found that cardiac magnetic resonance (CMR) led to a change in diagnosis, treatment, or both in 70% of out-of-hospital cardiac arrest (OHCA) survivors.¹

Each year, an estimated 424,000 Americans experience nontraumatic OHCA, which is the top cause of death in the world.² The majority of OHCA cases are caused by acute coronary syndromes (ACS), and American Heart Association and European guidelines recommend urgent angiography with a view to revascularization in resuscitated patients with suspected ACS.^3,4 Evidence of ACS is observed in only 30% to 40% of patients, however, and up to 30% of cases are linked to causes other than acute ischemia.^5,6

“While evidence of culprit lesion on angiogram supports acute ischemia as the cause of OHCA, diagnosis and clinical management of OHCA survivors with inconclusive coronary angiogram (either non-identifiable culprit lesion or unobstructed coronary arteries) is challenging,” the researchers wrote. They investigated the use of CMR in the diagnosis and management of 110 such patients (63% male; median age, 58) who underwent angiogram followed by CMR at 2 tertiary cardiac centers. 

Clinicians who were blinded to the CMR findings used pre-CMR imaging and clinical data to diagnose participants. CMR was considered to have a “clinical impact” if it led to a change in diagnosis, treatment, or both. 

CMR was found to be superior to transthoracic echocardiogram in identifying a pathologic substrate (69% vs 54%; P =.018), showing ischemic and nonischemic heart disease in 41% and 28% of patients, respectively. 

CMR demonstrated a clinical effect in 70% of patients, leading to a change in diagnosis (25%), management (29%), or both (16%). Findings were nonspecific in 8% of patients, and 23% had a structurally normal heart.

Accurate identification of OHCA etiology “plays a determinant role for appropriate treatment strategy and long-term prognosis,” the authors wrote. “CMR has a well-established diagnostic role, both in the ischemic and non-ischemic scenario, based on its superior tissue characterization properties,” and its use should be considered more often.

Disclosures

Dr Bucciarelli-Ducci is a consultant for Circle Cardiovascular Imaging, producer of the software used to assess ventricular function in the study. There are no additional disclosures.

References

1. Baritussio A, Zorzi A, Ghosh Dastidar A, et al. Out of hospital cardiac arrest survivors with inconclusive coronary angiogram: impact of cardiovascular magnetic resonance on clinical management and decision-making. Resuscitation. doi:10.1016/j.resuscitation.2017.03.039
2. Go AS, Mozaffarian D, Roger VL, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics–2014 update: a report from the American Heart Association. Circulation. 2014;129(3):e28-e292. doi:10.1161/01.cir.0000441139.02102.80
3. O’Gara PT, Kushner FG, Ascheim DD, et al; CF/AHA Task Force. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013;127(4):529-555. doi: 10.1161/CIR.0b013e3182742c84
4. Steg S, James SK, Atar A, et al. ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation. Eur Heart J. 2012;33(20):2569-2619. doi:10.1093/eurheartj/ehs215
5. Anyfantakis ZA, Baron G, Aubry P, et al. Acute coronary angiographic findings in survivors of out-of-hospital cardiac arrest. Am Heart J. 2009;157(2):312-318. doi:10.1016/j.ahj.2008.09.016
6. Chelly J, Mongardon N, Dumas F, et al. Benefit of an early and systematic imaging procedure after cardiac arrest: Insights from the PROCAT (Parisian Region Out of Hospital Cardiac Arrest) registry. Resuscitation. 2012;83(12):1444-1450. doi:10.1016/j.resuscitation.2012.08.321