Endomyocardial biopsy: what future in arrhythmogenic right ventricular dysplasia diagnosis?

Abstract Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a leading cause of sudden cardiac death, but its diagnosis is challenging and the role of endomyocardial biopsy (EMB) is controversial and has been recently questioned. Purpose We aimed to 1) analyse the role of EMB in improving the diagnostic performance of 2010 Task Force Criteria (TFC) in the diagnosis of ARVC; 2) assess EMB safety in our population. Methods We retrospectively analysed data from 54 consecutive patients admitted to our Hospital with a clinical suspicion of ARVC undergoing endomyocardial biopsy. During hospitalization a complete assessment was performed for every patient (including electrocardiogram, echocardiogram, cardiac MRI, genetic analysis, and electroanatomic-mapping-guided endomyocardial biopsy). ARVC diagnosis was assessed for every patient using both traditional 2010 TFC and a non-invasive modified TFC (2010 TFC criteria excluding biopsy). Results Overall, 9/54 (17%) patients showed a left-dominant variant of ARVC and were therefore excluded from the analysis. Non-invasive modified TFC allowed 16/45 (36%) patients to receive a definite diagnosis; when biopsy results were added the number of definite diagnosis increased to 22/45 (49%), increasing the number of patients with a definite diagnosis by 13%. More specifically: 8/11 patients not reaching a possible diagnosis were reclassified as either possible (4/8) or borderline (4/8); 3/9 patients with a possible diagnosis were reclassified as borderline; 6/9 borderline patients received a definite diagnosis of ARVC. Globally, in 6 out of 29 patients with a non-definite diagnosis, EMB confirmed ARVC diagnosis and 17/45 (38%) patients received an upgrade in their diagnostic status with EMB. Notably, EMB also revealed the coexistence of myocarditis and fibro-fatty replacement in 5/45 (9%) patients. No patient experienced complications related to EMB. Conclusions Endomyocardial biopsy is a safe, reliable, and useful tool for ARVC diagnosis, allowing to upgrade the diagnostic status of 38% of our patients with a suspect of ARVC diagnosis. It should be performed in experienced centers and it should be guided by electro-anatomic mapping, to maximize its diagnostic power. Funding Acknowledgement Type of funding source: None