Diagnostic Yield of Electroanatomic Voltage Mapping in Guiding Endomyocardial Biopsies

Background: Electroanatomic voltage mapping (EVM) is a promising modality for guiding endomyocardial biopsies (EMB). However, few data support its feasibility and safety. We now report the largest cohort of patients undergoing EVM-guided EMB in order to show its diagnostic yield and to compare it with a cardiac magnetic resonance (CMR) guided approach. Methods: One-hundred and sixty-two consecutive patients undergoing EMB at our Institution from 2010 to 2019 were included. EMB was performed in pathological areas identified at EVM and CMR. According to EMB results, CMR and EVM sensitivity and specificity regarding the identification of pathological substrates of myocardium were evaluated. Results: Pre-operative CMR showed late gadolinium enhancement (LGE) in 70% of the patients, while EVM identified areas of low voltages in 61%. Right (73%), left (19%) or both ventricles (8%) underwent sampling. EVM proved to have similar sensitivity to CMR (74% vs. 77%), with specificity being respectively 70% and 47%. In 12 patients with EMB-proven cardiomyopathy, EVM identified pathological areas, which had been undetected at CMR evaluation. Sensitivity of pooled EVM and CMR was as high as 95%. EMB analysis allowed to reach a new diagnosis, different from the suspected clinical diagnosis, in 39% of patients. Complications rate was low, mostly vascular access related, with no patients requiring urgent management. Conclusions: EVM proved to be a promising tool for targeted-EMB due to its sensitivity and specificity for identification of myocardial pathological substrates. EVM demonstrated to have an accuracy similar to CMR. EVM and CMR together conferred EMB a positive predictive value of 89%.