Electrogram‐guided endomyocardial biopsy yield in patients with suspected cardiac sarcoidosis and relation to outcomes

Abstract

Objective Endomyocardial biopsy (EMB) is a useful diagnostic tool though the yield may be limited in many myocardial diseases. Data on the diagnostic yield and prognostic significance of EMB guided by abnormal electrograms (EGM‐Bx) in suspected cardiac sarcoidosis (CS) are scarce. Methods Seventy‐nine patients (mean age: 56 ± 12 years; 61% men) with suspected CS based on clinical and imaging features underwent right or left ventricular EGM‐Bx guided by electroanatomic mapping. Tissue samples were obtained from sites with abnormal EGMs and/or abnormal cardiac imaging. The diagnostic yield of EGM‐Bx was evaluated in reference to histopathologic analysis. Left ventricular assist device (LVAD) and transplantation‐free survival were compared between patients with positive and negative EGM‐Bx for CS. Results A total of 254 samples were obtained from abnormal EGM sites, and 126 samples from normal EGM sites guided by pre‐procedure imaging findings. Abnormal histopathology was noted in 65 (26%) and 10 (8%) samples from abnormal and normal EGM sites, respectively. Histopathology confirmed CS in 16 (20%) patients, while an alternative tissue diagnosis emerged in 10 (13%) patients. Abnormal EGMs at the biopsy site had sensitivity 89% and specificity 33% for a histopathologic diagnosis of CS. LVAD and transplantation‐free survival were not significantly associated with the EGM‐Bx result (log‐rank p = .91). Conclusion In patients with suspected CS, abnormal EGM‐Bx has high sensitivity and low specificity for establishing a definite CS diagnosis. Consideration of substrate abnormalities apparent on preprocedural imaging as an adjunct for selection of biopsy sites may further improve EGM‐Bx yield.

Epidemiology, Pathogenesis, and Diagnosis of Cardiac Sarcoidosis

“… 63 , 64 , 65 Several factors impact yield, including technique, the patchy distribution of lesions having increased predilection for left heart favoring midmyocardial and subepicardial areas, and stage of disease. 66 If performed during chronic stages, granulomas and lymphocytic infiltration tend to disappear and are replaced by fibrosis. 35 EMB is required for confirmation of diagnosis in absence of extracardiac histological diagnosis and isolated cardiac sarcoidosis and to rule out other causes of fulminant cardiomyopathy, such as giant cell myocarditis.…”

“… 35 Electroanatomic mapping-guided EMB helps increase diagnostic yield up to 41%, with additional benefit from cardiac imaging. 64 , 66 The prognostic yield of EMB remains uncertain, with different studies providing contrasting results. 65 , 66 …”

“… 64 , 66 The prognostic yield of EMB remains uncertain, with different studies providing contrasting results. 65 , 66 …”

What cardiologists should know about cardiac sarcoidosis in 2022?

“…When there is no evidence of extra-CS on FDG-PET/CT and purely isolated CS is suspected, EMB should be considered and may be guided by electroanatomic mapping or CMR and FDG-PET/CT findings to overcome its low sensitivity of 25% [4]. Ezzeddine et al showed that when guided by abnormal electrograms, EMB yield could increase up to 41% [29 ▪ ]. This could increase even further when combining electrograms with anomalies on CMR and FDG-PET/CT [29 ▪ ] or when repeating EMB [26].…”

“…Ezzeddine et al showed that when guided by abnormal electrograms, EMB yield could increase up to 41% [29 ▪ ]. This could increase even further when combining electrograms with anomalies on CMR and FDG-PET/CT [29 ▪ ] or when repeating EMB [26].…”