Late Gadolinium Enhancement by Cardiac Magnetic Resonance Imaging and Major Adverse Coronary Events

Background: Coronary artery disease is the most common type of heart disease. CAD encompasses atherosclerosis and arteriosclerosis and is the leading cause of death in the United States in both men and women. This disease process involves the blood vessels responsible for supplying blood to the heart. Arteriosclerosis is described as a hardening of the vessels, while atherosclerosis is the obstruction of vessels due to genetics and dietary/lifestyle activities. In the long-term, these abnormalities can lead to myocardial infarction (MI), valvular heart disease, chest pain or angina, and heart failure. Standard practice of care currently involves the use electrocardiogram (ECG), computed tomography (CT), and echocardiogram in order to monitor cardiac function. A new emerging imaging study, cardiac magnetic resonance with late gadolinium enhancement, has shown to be a promising prognostic tool in evaluating patient’s risks for major adverse coronary events (MACE). CMR is a medical imaging technology for non-invasive assessment for the function and structure of the heart. Gadolinium is a contrast agent that can be injected during the CMR study that localizes in cardiac cicatrix tissue. If the imaging study has a positive result, it may lend evidence that cardiac function is below optimal and may put patient at risk for MACE in the future. Methods: An exhaustive search of available medical literature was performed using the following databases: MEDLINE-OVID, MEDLINE-Pubmed, and CINAHL-EBSCO Host. Articles were discovered using the following terms: MRI, Coronary heart disease, gadolinium, LGE, and cicatrix. Relevant articles were assessed for quality using GRADE. Results: Three studies met the inclusion criteria and were included in this systematic review. All three of these cohort studies demonstrated that the presence of scar tissue, identified by late gadolinium enhancement (LGE), had a positive predictive value of major adverse cardiac events (MACE) in patients with symptoms or signs suspicious of coronary artery disease (CAD). Studies demonstrated hazard ratios for MACE in LGE positive patients ranging from 4.69 to 11.48. Conclusion: The use of late gadolinium enhancement as an adjunct to cardiac magnetic resonance (CMR) testing has shown to be a valuable asset in predicting major adverse coronary events such as myocardial infarction and cardiac death. These events were followed for an accumulative median of 19 months, spanning from 6 months to 4.7 years. From the high-quality evidence gathered, LGE was a strong predictor of MACE and may have an invaluable future in stratifying risk among patient populations with clinical CAD. Keywords: MRI, coronary heart disease, gadolinium, and cicatrix