Cardiac MRI after Sudden Cardiac Arrest: A Systematic Review

Purpose: To perform a systematic review to assess the diagnostic and prognostic value of cardiac MRI after sudden cardiac arrest (SCA). Materials and Methods: PubMed and Cochrane Library databases were systematically searched for studies investigating cardiac MRI after SCA in adult patients (>= 18 years of age). The time frame of the encompassed studies spans from January 2012 to January 2023. The study protocol was preregistered in OSF Registries (www.osf.io/nxaev) , and the systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta -Analyses (PRISMA) guidelines. The quality of the included studies was evaluated using the Newcastle -Ottawa quality assessment scale. Results: Fourteen studies involving 1367 individuals, 1257 (91.9%) of whom underwent cardiac MRI, were included. Inconsistent findings were reported on the diagnostic value of cardiac MRI-specific findings. The included studies demonstrated the following main findings: (a) cardiac MRI led to a new or alternative diagnosis in patients with SCA; (b) cardiac MRI identified pathologic or arrhythmogenic substrates; (c) cardiac MRI helped detect myocardial edema (potentially reversible); (d) cardiac MRI provided evidence for the occurrence of adverse events; and (e) functional markers or ventricular dimensions were considered prognostically relevant in a few studies. Relevant challenges in this systematic review were the lack of comparators and reference standards relative to cardiac MRI as the index test and patient selection bias. Conclusion: Cardiac MRI following SCA can contribute to the diagnostic process and offer supplementary information essential for treatment planning. Limitations of the review include studies with insufficient comparators and potential bias in patient selection.