Cardiac Magnetic Resonance to Reclassify Diagnosis and Detect Cardiomyopathies in Hospitalized Patients with Acute Presentation

Background: Cardiomyopathies are a significant cause of heart failure, arrhythmia, and cardiac morbidity in the general population. Cardiovascular magnetic resonance (CMR) is a valuable tool for the diagnostic work-up of patients with acute cardiac events. Objectives: This study evaluated the diagnostic value of CMR and the yield of cardiomyopathies in hospitalized cardiac patients with acute presentation. Methods: A retrospective analysis was conducted with 535 consecutive hospitalized patients who underwent CMR at Hippokration Hospital, Athens, Greece, to identify a subset of scans performed on an urgent basis of hospitalized patients. Demographic data, causes of admission, CMR findings, and plasma cardiac biomarkers (hs-Troponin I, NT-proBNP, and CRP) were systematically recorded. Results: Out of the initial 535 CMR scans evaluated, a further analysis was conducted with 104 patients who were in hospital and underwent CMR on an urgent basis. From the total population of hospitalized patients, 33% had CMR findings indicative of underlying cardiomyopathy, with dilated cardiomyopathy being the most common subtype (36%), followed by arrhythmogenic cardiomyopathy (27%), hypertrophic cardiomyopathy (15%), or other subtypes (e.g., cardiac amyloidosis, sarcoidosis, endomyocardial fibrosis, EGPA, or unclassified). CMR led to the reclassification of the initial diagnosis into that of underlying cardiomyopathy in 32% of cases. The highest reclassification rate was observed within the subgroup with heart failure (71%), followed by that of acute myocardial infarction/ischemic heart disease (24%) and myocarditis (22%). Conclusions: CMR imaging effectively contributed to the differential diagnosis of hospitalized patients with acute cardiac events that remained without a definitive diagnosis after their initial work-up and uncovered underlying cardiomyopathy in almost one-third of this cohort.