Cardiac magnetic resonance in suspected MINOCA patients, clinical and imaging profile, diagnostic performance and 1 year clinical follow up

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) is fundamental at the evaluation of patients with differential diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) due to its tissue characterization potential to exclude non-ischaemic causes such as myocarditis and Takotsubo syndrome and better stratify ischaemic disease in acute and chronic disease. Purpose To describe the clinical profile, cardiac magnetic resonance findings, final clinical and CMR diagnosis and clinical 1-year follow-up in patients with a working diagnosis of MINOCA evaluated with a CMR. Methods All patients who underwent a CMR for suspected MINOCA during a period of 1 year from June 2021 to June 2022 were retrospectively evaluated, past medical history, clinical characteristics, CMR reports and 1 year follow up were obtained. Myocarditis was defined by modified Lake Louise criteria. Patients were stratified following CMR diagnosis, accurate CMR diagnosis was considered when matched clinical final diagnosis. Results A total of 107 patients were evaluated with a CMR for a suspected MINOCA from June 2021 to June 2022, of whom CMR classified 51 (47.7%) as myocarditis, 11 (10.3%) as Takotsubo syndromes, 13 (12.2%) as acute ischaemic etiology, 3 (2.8%) as chronic ischaemic etiology, 24 (22.4%) as normal CMR and 5 (4.7%) had other diagnoses (cardiomyopathies and type II myocardial infarctions). Myocarditis patients were younger and more frequently males, ischaemic etiologies were older, had more comorbidities and were more frequently males, Takotsubo syndromes were more frequently females and were frequently hypertense. (Table 1) The final clinical diagnosis corresponded to the diagnosis provided by CMR in 92.2% of myocarditis, 100% of Takotsubo syndromes, 84.6% in acute ischaemic etiologies and 100% of chronic ischaemic etiologies. Patients with a normal CMR or other diagnosis had significantly lower correspondence between final and CMR diagnosis, in this setting CMR was still useful to rule out ischaemic etiology, myocarditis and Takotsubo syndrome. During follow-up there were no clinical differences between groups in terms of deaths, readmissions myocardial infarction and visits for recurrent chest pain. Patients with myocarditis CMR diagnosis were more likely to be followed up with CMR than other groups. (Table 2). Conclusions The final diagnosis of the patient studied for suspected MINOCA was given