1356340 - The incremental role of CMR in the evaluation and decision-making of NICMP

Cardiovascular magnetic resonance (CMR) is a vital diagnostic modality for patients with heart failure. However, the role of CMR in informing and altering decision-making and prognosis as a result of alterations in clinical management has not been previously studied in detail, especially in patients with non-ischemic cardiomyopathy (NICMP). CMR remains the gold standard for assessing myocardial anatomy, regional and global function, tissue characterization, and parameters such as left ventricular ejection fraction (LVEF), late gadolinium enhancement (LGE), and T1/T2 mapping are frequently used to make management decisions regarding the etiology, drug therapy, and devices.

Methods:

We performed a retrospective analysis of patients between the ages of 18 to 92 years (median 56) who underwent CMR at our university hospital system over the last three years. Charts were reviewed for echocardiographic findings, changes in the underlying diagnosis or therapy, procedures including further noninvasive or invasive tests (e.g., serum free light chains or biomarkers, catheterization or organ biopsy, pyrophosphate scan, etc.), and a change in decision-making over a median follow-up of 36 months. Decision-making changes were defined as precise etiology, new consultations or surgical or cardiology procedures or testing yielding clinically actionable new information, and initiation or discontinuation of medications.

Results:

Data were available for 76 patients from June 2019 to September 2022 – more patients are still being analyzed. In our interim analysis, CMR provided significant decision-making information in 66% of cases. 54% of the patients had a further specification of their underlying etiology. Another 47% of the patients gained a new or ruled-out structural diagnosis. LGE was detected in 23% of the patients. 25% of the patients had a change in their treatment plan or drugs (e.g., tafamidis or SGLT2i, etc.). Mean LVEF by CMR was significantly higher (49.16 ± 18.04%) than TTE (44.43 ± 17.35), with a mean difference of 4.73 ± 5.8%. The correlation between the two modalities was fair (r²=0.82, p< 0.0001).

Conclusion:

CMR effectively evaluates non-ischemic cardiomyopathy and has a substantial impact on characterizing underlying etiology and management. CMR provided important information in about two-thirds of the patients, which resulted in a change in the management. Additionally, this effect on clinical management occurred independently of LVEF variations between TTE and CMR. These results suggest that in addition to accurate LVEF and tissue characterization, CMR also provides actionable information that significantly impacts diagnosis and clinical decision-making.