The State of the Heart Biopsy: A Clinical Review

Endomyocardial biopsy (EMB) is an invaluable and underused diagnostic tool for myocardial disease. The primary indications are surveillance of cardiac allograft rejection and the diagnosis of inflammatory and infiltrative cardiomyopathies. EMB is typically performed by sampling the right ventricular septum via the right internal jugular vein using fluoroscopic guidance. The diagnostic yield of EMB is improved by sampling both ventricles and with the use of guidance from imaging or electroanatomic mapping. The risk of major cardiac complications is operator dependent and < 1% in experienced centres. EMB is the gold standard and most common form of cardiac allograft rejection surveillance, whereas advanced cardiac imaging and donor-specific antibody quantification provide complementary information. Gene expression profiling is an alternative surveillance strategy to EMB for low-risk patients. EMB is recommended for myocarditis and can guide therapy for giant-cell myocarditis, necrotizing eosinophilic myocarditis, sarcoidosis, and immune checkpoint inhibitor myocarditis. There is growing interest in using EMB to guide therapy for viral myocarditis, although the uptake of this approach is limited to specialized centres. EMB has been replaced as a first-line test for infiltrative cardiomyopathy by nonbiopsy diagnostic techniques, but is still useful to clarify the diagnosis or disease subtype. The miniaturization of bioptomes and advances in laboratory techniques such as microarrays promises to improve the safety and yield of EMB. We review the contemporary use of EMB for cardiac allograft rejection, inflammatory cardiomyopathy, and infiltrative cardiomyopathy. La biopsie endomyocardique est un outil diagnostique sous-utilisé et très utile en cas de maladie myocardique. Ses principales indications sont la surveillance du rejet d’une allogreffe cardiaque et le diagnostic des cardiomyopathies restrictives (infiltrantes) et inflammatoires. La biopsie endomyocardique est généralement réalisée en prélevant un échantillon du septum ventriculaire droit par la veine jugulaire interne droite, sous guidage fluoroscopique. Le succès diagnostique de la biopsie endomyocardique est amélioré en prélevant un échantillon des deux ventricules et en utilisant le guidage par imagerie ou cartographie électroanatomique. Le risque de complications cardiaques majeures varie en fonction de la personne qui effectue l’intervention, et est de moins de 1 % dans les centres où cette interve