HEllenic Registry on Myocarditis SyndromES on behalf of Hellenic Heart Failure Association: The HERMES-HF Registry

Update on Myocarditis: From Etiology and Clinical Picture to Modern Diagnostics and Methods of Treatment

Although the frequency of myocarditis in the general population is very difficult to accurately determine due to the large number of asymptomatic cases, the incidence of this disease is increasing significantly due to better defined criteria for diagnosis and the development of modern diagnostic methods. The multitude of different etiological factors, the diversity of the clinical picture, and the variability of the diagnostic findings make this disease often demanding both for the selection of the diagnostic modality and for the proper therapeutic approach. The previously known most common viral etiology of this disease is today overshadowed by new findings based on immune-mediated processes, associated with diseases that in their natural course can lead to myocardial involvement, as well as the iatrogenic cause of myocarditis, which is due to use of immune checkpoint inhibitors in the treatment of cancer patients. Suspecting that a patient with polymorphic and non-specific clinical signs and symptoms, such as changes in ECG and echocardiography readings, has myocarditis is the starting point in the diagnostic algorithm. Cardio magnetic resonance imaging is non-invasive and is the gold standard for diagnosis and clinical follow-up of these patients. Endomyocardial biopsy as an invasive method is the diagnostic choice in life-threatening cases with suspicion of fulminant myocarditis where the diagnosis has not yet established or there is no adequate response to the applied therapeutic regimen. The treatment of myocarditis is increasingly demanding and includes conservative methods of treating heart failure, immunomodulatory and immunospressive therapy, methods of mechanical circulatory support, and heart transplantation. The goal of developing new diagnostic and therapeutic methods is to reduce mortality from this complex disease, which is still high.

HEllenic Registry on Myocarditis SyndromES on behalf of Hellenic Heart Failure Association: The HERMES-HF Registry

AIMS

Despite the existence of many studies, there are still limited data about the characteristics of myocarditis in Greece. This led to the creation of the Greek Myocarditis Registry aiming to document the different symptoms and treatment of myocarditis, assess possible prognostic factors, and find similarities and differences to what is already published in literature. This paper is a preliminary descriptive analysis of this Registry.

METHODS AND RESULTS

We analysed data for the hospitalization period of all patients included in the Registry from December 2015 until November 2017. Statistics are reported as frequency (%) or median and inter-quartile range (IQR) as appropriate. In total, 146 patients were included; 83.3% of the patients reported an infection during the last 3 months. The most common symptom, regardless of the underlying infection, was chest pain (82.2%) followed by dyspnoea (18.5%), while the most common finding in clinical examination was tachycardia (26.7%). Presentation was more frequent in the winter months. ECG findings were not specific, with the repolarization abnormalities being the most frequent (60.3%). Atrial fibrillation was observed in two patients, both of whom presented with a reduced ventricular systolic function. Left ventricular ejection fraction changed significantly during the hospitalization [55% (IQR: 50-60%) on admission vs. 60% (IQR: 55-60%) on discharge, P = 0.0026]. Cardiac magnetic resonance was performed in 88 patients (61%), revealing mainly subepicardial and midcardial involvement of the lateral wall. Late gadolinium enhancement was present in all patients, while oedema was found in 39 of them. Only 11 patients underwent endomyocardial biopsy. Discharge medication consisted mainly of beta-blockers (71.9%) and angiotensin-converting enzyme inhibitors (41.8%), while 39.7% of the patients were prescribed both.

CONCLUSIONS

This preliminary analysis describes the typical presentation of myocarditis patients in Greece. It is a first step in developing a better prognostic model for the course of the disease, which will be completed after the incorporation of the patients' follow-up data.