Impact of cardiac magnetic resonance on the diagnosis and management of patients with cardiomyopathies

Abstract Background Cardiac magnetic resonance (CMR) is an essential tool for diagnosis and prognosis in patients with cardiomyopathies. Over the past decades, it has become the gold standard for assessing cardiac function, volumes and mass. In addition, its tissue characterization capabilities, including T1, T2 and T2* mapping and gadolinium enhancement images, allow differentiation between ischemic, inflammatory and infiltrative etiologies of heart disease. Aims The main objective of the study was to evaluate the impact of CMR in the diagnosis and management of patients with suspected cardiomyopathies. The secondary objective of the study was to identify predictors that influence the diagnosis and management of patients with cardiomyopathies, as confirmed by CMR. The primary endpoint of the study was the significant clinical impact (SCI), a binary variable (yes/no), defined as the change/no change in the diagnosis or the change/no change in clinical management. Methods We retrospectively analyzed the medical charts and CMR evaluations of 594 consecutive patients referred for CMR in two centers between January 2021 and March 2022. In this study, we only included patients with cardiomyopathies/myocarditis. Results The study sample included 272 patients: 179 patients (65.8%) were male and the mean (SD) age was 49 (14) years. All patients underwent contrast-enhanced CMR. Late gadolinium enhancement (LGE) was detected in 177 patients (65%). In 44% of the cases, the final diagnosis based on CMR differed from the initial assessment and in 47% of cases, there was a change in management. Overall, CMR had a significant clinical impact in 66% of cases. LVEF (OR 0.97, 95% CI, p=0.002), LVESVi (OR 1.01, 95% CI, p=0.012), RVEF (OR 0.97, 95% CI, p=0.002) and LGE (OR 1.84, 95% CI, p=0.019) were predictors of SCI by univariable analysis. In a multivariable model, LGE (OR 1.72, 95% CI, p=0.038) and LVESVi (OR 1.01, 95% CI, p=0.021) proved to be independent predictors for significant clinical impact. Conclusions Our study provides evidence supporting the value of CMR imaging as a diagnostic tool of cardiomyopathies, which impacts patient management.