P4652Magnetic resonance and electroanatomical guided endomyocardial biopsy as a diagnostic tool in the clinician's box: a 5 year experience
Authors: Casella M , Dello Russo A , Gasperetti A , Basso C , Conte E , Della Rocca A , Catto V , Moltrasio M , Fassini G , Musthaq S , Andreini D , Natale A , Tondo C 
Published: October 2019

Abstract

Background
Percutaneous endo-myocardial biopsy (EMB) is an invasive diagnostic test used to reach or confirm a diagnosis when structural or substrate anomalies are suspected, such as in cardiomyopathies or myocarditis evaluation. In recent years, cardiac magnetic resonance imaging (MRI) and endo-cavitary electro-anatomical mapping (EAM) have been used to localize the most significant myocardial area to sample, therefore increasing EMB overall effectiveness and reliability.

Purpose
To describe and characterize safety, feasibility and anatomical findings of a large cohort of patients (pts) undergoing diagnostic EMB and to assess its impact on the treatment decision making algorithm.

Methods
A cohort of all pts undergoing a percutaneous EMB at our Institution from January 2014 to January 2019 was analyzed. All EMB procedures were guided by a pre-procedural cardiac MRI radiological alteration analysis and an endo-cavitary EAM. Intra-cardiac echography (ICE) was used in all procedures, to directly visualize the sample area and to evaluate in real time post-EBM complications. Demographics, clinical data, MRI data, pathological EMB features, and peri-procedural data were systematically retrieved.

Results
One-hundred and eleven pts were enrolled (78% male, 47±4 y.o., 33% athletes). EMB indication was abnormal MRI findings in 94 (85%), pathological EMB voltages in 10 (9%) and clinical suspect and patient history in 7 (6%) pts.
EMB sample area was determined by both MRI and EAM pathological area analysis in 92 (83%) pts, while by EAM alone in 19 (17%) pts (n=6 pathological unipolar EAM; n=13 bipolar and unipolar pathological EAM). The sample site was the right ventricle in 89 (80%), the left ventricle in 20 (18%), and both in 3 (2%) pts.
In 103 (93%) pts a concomitant electrophysiological induction study was performed (40% positive for sustained ventricular arrhythmias) and 35 (32%) pts underwent a trans-catheter ablation (TCA) (n=8 epicardial TCA; n=2 endo-epicardial TCA; n=25 endocardial ATC). Only 2 (2%) peri-procedural adverse events were witnessed, specifically femoral pseudo-aneurysms, requiring surgical repair. EMB analysis allowed to confirm 58 (52%) pre-procedural diagnosis and to reach 32 (29%) new diagnosis, while resulting inconclusive or non-specific in the diagnostic process only in 21 (19%) cases [Figure1]. A total of 33 (30%) intra-cardiac devices (ICDs) were implanted contextually in the cohort, of which 9 (8%) solely upon EMB indication; in 4 (4%) other patients, biopsy represented a strong decisional factor in the multi-modality decision process for abstaining from ICD implant.
Dashed lines: diagnosis changed upon EMB

Conclusion
MRI and EAM guided EMBs allowed to finely define a large cohort of patients by representing a disease defining parameter in over 80% of the enrolled pts while and a decision shifting parameter in ICD implant algorithm in a high % of pts.