Response to letter regarding article, "contribution and risk of left ventricular endomyocardial biopsy in patients with cardiomyopathies: a retrospective study over a 28-year period".

Abstract

HomeCirculationVol. 130, No. 4Response to Letter Regarding Article, “Contribution and Risk of Left Ventricular Endomyocardial Biopsy in Patients With Cardiomyopathies: A Retrospective Study Over a 28-Year Period” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBResponse to Letter Regarding Article, “Contribution and Risk of Left Ventricular Endomyocardial Biopsy in Patients With Cardiomyopathies: A Retrospective Study Over a 28-Year Period” Andrea Frustaci, MD and Cristina Chimenti, MD, PhD Andrea FrustaciAndrea Frustaci Cardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences Department, La Sapienza University, Cellular and Molecular Cardiology Lab, IRCCS L. Spallanzani, Rome, Italy Search for more papers by this author and Cristina ChimentiCristina Chimenti Cardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences Department, La Sapienza University, Cellular and Molecular Cardiology Lab, IRCCS L. Spallanzani, Rome, Italy Search for more papers by this author Originally published22 Jul 2014https://doi.org/10.1161/CIRCULATIONAHA.114.009355Circulation. 2014;130:e31The letter by Andreoletti et al allows us to comment on the contributive role of endomyocardial biopsy (EMB) and whether this procedure should be reserved to a few highly specialized centers. Indeed, the use of EMB is already limited in the world, particularly if compared with the diffusion following its introduction in 1963 by Konno and Sakakibara1 that reached its peak in the 1980s. The initial enthusiasm to finally have a powerful diagnostic instrument was sobered by the evidence of a clear discrepancy between the limited histological pattern of degeneration, inflammation, infiltration, and storage with the extreme variability of possible causes and mechanisms of damage often making the translational impact of EMB disappointing.2 In this regard, Andreoletti’s report on the contribution of polymerase chain reaction combined with mass spectrometry to the identification of viral agents emphasizes how the investigational properties of EMB can be enhanced in specialized centers. It can be argued that the concentration of EMB in few centers would necessarily restrict the procedure to a limited number of patients and that the current therapeutic implications from the identification of myocardial viral genomes are still unsatisfactory. In fact, some viruses, like Parvovirus B19, are resistant to antiviral therapy; some others, such as hepatitis C virus and perhaps Epstein-Barr virus, include an immune-mediated mechanism of damage; and, finally, the use of effective antiviral agents like β-interferon, particularly for enterovirus and adenovirus, is limited to the milder forms (patients with a left ventricular ejection fraction of >30%) because of the initial impairment of cardiac contractility.3 It is therefore desirable that the most technologically advanced institutions would identify treatable pathways of myocardial disease that might be easily recognized in small clinical centers. In particular, in the context of myocardial inflammation, beyond the recognized steroid and immunosuppression-sensitive eosinophilic, giant cells, and granulomatous myocarditis, it is important to identify an autoimmune pathway. At present, it seems that the expression of human leukocyte antigen DR on cardiomyocyte membrane, easily detectable by immunohistochemistry in every pathology laboratory, might predict the response of myocarditis to immunosuppressive therapy. Among the degenerative myocardial diseases, such as dilated cardiomyopathy, the evidence of reduced myofibrillar content of myocytes, and of low cell proliferation (cKit, Ki67, MCM5-positive cells), as well, may suggest a potential benefit from the use of growth factors such as growth hormone. Finally, the detection of oxidative myocardial stress, resulting from overexpression in the cardiomyocytes of nitrotyrosine and inducible nitric oxide synthase, may suggest the infusion of antioxidant agents such as recombinant manganese superoxide dismutase. Several diseases such as cocaine-related, diabetic, radiation-induced, and toxic (ie, from antineoplastic drugs) cardiomyopathy appear to potentially benefit from antioxidant therapy. In summary, EMB can be extended to peripheral centers because it is safe and highly contributive.4 A strong relationship with highly specialized centers is desirable for the cultural translation of treatable myocardial pathways.Andrea Frustaci, MDCristina Chimenti, MD, PhDCardiovascular, Respiratory, Nefrologic, Anestesiologic and Geriatric Sciences DepartmentLa Sapienza UniversityCellular and Molecular Cardiology LabIRCCS L. SpallanzaniRome, ItalyDisclosuresNone.