Sarcoidosis is a multiorgan granulomatous inflammatory disease whose prevalence in the Czech Republic is approximately 60 cases per 100 000 inhabitants [50]. It affects most frequently lungs and lymphatic nodes. Cardiac sarcoidosis manifests in about 5 % of patients [58], even though bioptical findings of cardiac sarcoidosis were proved in up to 23 % of patients [59]. The histological finding of cardiac sarcoidosis is in some respects similar to GCM like the presence of giant cells, however in cardiac sarcoidosis greater extent of fibrous changes and primarily smaller presence of the myocardial necrosis and the presence of well-bordered granulomas may be observed [49, 50]. Aetiology of the disease is unclear. According to the references, it is most likely connected with not quite explained genetical and immunological aspects and it is sometimes put in relation to different infectious and non-infectious agents (Borrelia burgdorferi, Mycobacterium, Mycoplasma, environmental influence etc), [58].
Clinical manifestation of cardiac sarcoidosis is varied. It presents with heart failure under the picture of dilated or restrictive cardiomyopathy and with arrhythmias [50]. In the Finnish study published in 2014 [60], 44 % of patients with cardiac sarcoidosis presented with AV block, 33 % with ventricular tachycardia or fibrillation and 18 % with heart failure. The same study evaluated even ECG, ECHO, CMRI and PET findings, treatment results and mortality. A very often ECG finding was AV block of the 2nd or 3rd degree (45 %), RBBB (37 %) and LBBB (21 %). During ECHO examinations, except decreased left ventricular EF in approximately 50 % of patients, even left ventricular dilatation and changes in the dimensions of the interventricular septum were described. There were even some findings of the right ventricular aneurysm [50].
CMRI has an important role in the diagnosis of cardiac sarcoidosis where except above-mentioned findings, even LGE is presented in the most of patients with the localization in basal segments of the interventricular septum and lateral wall of the LV in the epicardium and the middle layer of the myocardium [50]. PET examination is also used when inflammatory activity is detected by 18F-FDG (fluorodeoxyglucose), [50]. The sensitivity of EMB in cardiac sarcoidosis is 20 to 25 % [50]. The sensitivity was in one Canadian patient increased with the previous electroanatomic mapping of the heart ventricle [61].
Like in eosinophilic and giant-cell myocarditis, even in cardiac sarcoidosis, the main therapeutic method is immunosuppressive therapy. This treatment is usually administered in monotherapy or in combination with other immunosuppressive drugs, primarily methotrexate. In the treatment of arrhythmias and prevention of sudden cardiac death, implantation of a permanent pacemaker or ICD is considered [62]. ACE inhibitors, beta-blockers and alternatively diuretics are recommended in heart failure treatment. Digoxin is not commonly recommended [58]. Primarily in patients with advanced heart failure, the heart transplant is sometimes necessary [50]. Prognosis varies in different studies. According to the Finnish study [60], 10-year survival rate including patient without the necessity of heart transplant was 83 % (for comparison with the study from 2003 – 5-year survival rate was 70 %), [49]. Worse prognosis is in patients with an isolated form of cardiac sarcoidosis with an initial manifestation with heart failure with the 10-year survival rate of 52 %.
Author of the opening picture: Yale Rosen from USA
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References:
49) OKURA a et al. A clinical and histopathologic comparison of cardiac sarcoidosis and idiopathic giant cell myocarditis. Journal of the American College of Cardiology [online]. 2003, 41(2), 322 [cit. 2017-02-05].
50) KUBÁNEK a VOSKA L. Obrovskobuněčná myokarditida a sarkoidóza srdce – update 2015. Kardiologická revue – Interní medicína. 17(4), 295-299.
58) T., JR., COOPER. Chapter 18: Cardiac Sarcoidosis. In: L.T., JR., COOPER, ed. Myocarditis: From Bench to Bedside. USA: Humana Press, 2003. pp. 421-436. ISBN 1-58829-112-X.
59) MORIMOTO a et al. Epidemiology of sarcoidosis in Japan. European Respiratory Journal [online]. 2008, 31(-), 372-379 [cit. 2017-02-07].
60) KANDOLIN. Cardiac Sarcoidosis: Epidemiology, Characteristics and Outcome over 25 Years in a Nationwide Study. Circulation [online]. 2014, 2014(-), 1-35 [cit. 2017-02-05].
61) B., NERY a et al. Isolated Cardiac Sarcoidosis: Establishing the Diagnosis With Electroanatomic Mapping-Guided Endomyocardial Biopsy. Canadian Journal of Cardiology. 2013, 2013(29), 1015.e1 – 1015.e3.
62) H., BIRNIE a et al. HRS Expert Consensus Statement on the Diagnosis and Management of Arrhythmias Associated With Cardiac Sarcoidosis. Heart Rhythm. 2014, 11(7), 1304–1323.
