Speckle-Tracking Echocardiography as an Effective Screening Tool for Cardiac Involvement Among Patients With Systemic Sarcoidosis in an Indian Cohort: A Prospective Observational Study.

Introduction: Diagnosing cardiac sarcoidosis (CS) is challenging due to the lack of a sensitive gold standard diagnostic test. Although advanced imaging techniques like cardiac magnetic resonance imaging (MRI) (cardiovascular magnetic resonance [CMR]) and fluorodeoxyglucose positron emission tomography (FDG-PET) CT are promising, they are limited by their availability and cost. Two-dimensional speckle-tracking echocardiography (2D-STE) is emerging as a valuable tool for the early detection of CS.

Methods: This single-center observational study assessed cardiac involvement and the utility of STE as a screening tool for diagnosing CS among newly diagnosed, histologically confirmed, treatment-naïve patients with systemic sarcoidosis in an Indian cohort.

Results: The study included 48 newly diagnosed sarcoidosis patients with a median age of 42.5 years (interquartile range [IQR] 34-53.5), of whom 52.1% were female. FDG-PET CT findings suggested cardiac involvement in 21 patients, while CMR findings were positive in 11 patients. All patients had normal 12-lead ECGs and echocardiograms. Twenty-five patients met the HRS 2014 criteria for CS diagnosis. The median (IQR) left ventricular global longitudinal strain (LV GLS) was -15.4 (-16.2, -13.4) in the probable CS group and -17.9 (-19.4, -17.4) in the non-CS group. An LV GLS cutoff of >-17.3 showed a sensitivity of 80.00% and a specificity of 82.61% (p < 0.001, area under the curve [AUC] = 0.790) for CS diagnosis. A right ventricular global longitudinal strain (RV GLS) cutoff of >-21.4 showed a sensitivity of 68.00% and a specificity of 78.26% (p < 0.017, AUC = 0.692). They both have very high negative predictive value (98.7% and 97.9%) and thus useful for ruling out the cardiac involvement than confirming it.

Conclusion: STE effectively screens for cardiac involvement in sarcoidosis patients, ruling out CS diagnosis.