Focal Myocardial Damage in Cardiac Sarcoidosis Characterized by Strain Analysis on Magnetic Resonance Tagged Imaging in Comparison with Fluorodeoxyglucose Positron Emission Tomography Accumulation and Magnetic Resonance Late Gadolinium Enhancement:

Left ventricular myocardial deformation assessment in asymptomatic patients with recently diagnosed sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis

BACKGROUND

Sarcoidosis is a systemic granulomatous disease affecting different organs including the heart. Myocardial strain analysis could potentially detect the early stages of cardiac dysfunction in sarcoidosis patients. The present study aims to assess the use of cardiac magnetic resonance (CMR) strain analysis using feature tracking (FT) in the detection of early cardiac involvement in asymptomatic patients with sarcoidosis.

METHODS

One hundred and thirteen CMR studies of patients with sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis without pre-existing known cardiovascular disease were included in the study and analysed using FT and compared to 22 age and gender-matched controls. Global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) of the left ventricle (LV) were measured.

RESULTS

The sarcoidosis patients did not significantly differ from the controls in basic demographic data and had normal global and regional systolic LV function-LV ejection fraction (EF) 66 ± 7% vs 65 ± 5% in the controls (p = NS). No statistically significant differences were found in all strain parameters between patients and controls: GLS (- 13.9 ± 3.1 vs. - 14.2 ± 2.5), GCS (- 23.4 ± 4.0 vs. - 22.2 ± 2.9) and GRS (53.4 ± 13.5 vs. 51.2 ± 13.6%) (p = NS).

CONCLUSION

Patients with sarcoidosis of the respiratory tract and/or extrapulmonary sarcoidosis had normal myocardial deformation measured by CMR-FT derived global strain.

The role of cardiac magnetic resonance in diagnosis of cardiac sarcoidosis

Sarcoidosis is a systemic granulomatous disease with a high prevalence of cardiac involvement in autopsic studies. Cardiac sarcoidosis is associated with increased cardiovascular morbidity and mortality. Endomyocardial biopsy is a specific technique, but unfortunately not sensitive enough. Non-invasive cardiac imaging has an important role in the evaluation of patients with suspected or confirmed cardiac sarcoidosis. Echocardiography remains the first choice imaging technique because of its availability and low cost. However, this method could not provide tissue characterization or evaluation of disease activity level. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has essential role in diagnosis and monitoring of patients with suspected or confirmed cardiac sarcoidosis. Nevertheless, more recently it has been shown that cardiac magnetic resonance (CMR) might provide useful information about cardiac sarcoidosis. Hybrid imaging approach that includes PET-CMR and PET-CT is particularly interesting for diagnosis, assessment of activity and follow-up in these patients. Diagnostic algorithm in sarcoidosis patients should include clinical data, hybrid imaging and biopsy. Use of different CMR sequences such as cine imaging, late gadolinium enhancement, T1 and T2 mapping, as well as strain imaging, may significantly contribute to diagnosis and monitoring of patients with cardiac sarcoidosis. However, validation of these techniques and particularly T1 and T2 mapping in sarcoidosis patients in large studies is necessary. This review aimed to summarize current knowledge about clinical usefulness of CMR in patients with cardiac sarcoidosis.