GIANT CELL MYOCARDITIS: A RARE AND LETHAL DIAGNOSIS

Abstract

SESSION TITLE: Monday Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Giant cell myocarditis (GCM) is a rare, rapidly progressive, and frequently fatal myocardial disease in otherwise healthy young and middle-aged adults. It is attributed to a T lymphocyte-mediated inflammation of the myocardium. Here, we present the case of an acute onset of exertional dyspnea that rapidly progressed to cardiogenic shock requiring a left ventricular assist device (LVAD), due to newly-developed giant cell myocarditis. CASE PRESENTATION: A 21-year-old male with a past medical history of asthma presented with 3 weeks of exertional dyspnea. He was in his usual state of health, when he developed flu-like symptoms 1 month ago. On resolution, he had a cough with clear sputum that persisted. The patient also reported orthopnea, paroxysmal nocturnal dyspnea, and increased dyspnea on exertion with decreased exercise tolerance. On admission, his proBNP was 11,200 and troponin-T was 0.360. EKG showed ST abnormalities in the anteroseptal leads. Transthoracic echocardiogram (TTE) showed a left ventricular ejection fraction (LVEF) of 35 % with a severely hypokinetic anterior wall. Initially, viral myocarditis was suspected, however it was ruled out after infectious workup was negative. ESR was 51 and CRP was 3.01. Cardiac MRI showed scaring in all 3 coronary artery territories and moderate global hypokinesis of the right ventricle, as well as moderate pericardial effusion and bilateral pleural effusions. The patient continued to deteriorate and developed cardiogenic shock, at which point a LVAD was placed. Endomyocardial biopsy of the right ventricle showed myocyte necrosis, multinucleated giant cells, and prominent interstitial mixed inflammatory infiltrate with lymphocytes and eosinophils consistent with giant cell myocarditis. The patient was started on immunosuppressive therapy and follow up TTE in 6 months showed an LVEF of 61% with complete resolution of symptoms. Given full cardiac recovery, it was decided that the LVAD would be explanted. DISCUSSION: GCM is a rare disease with high morbidity and mortality. The most common manifestations are heart failure, ventricular arrhythmias, and atrioventricular block, but it can also present as an acute myocardial infarction or even sudden cardiac death. Diagnosis rests on myocardial biopsy and cardiac MRI, which often shows hyper-enhancement sparing of the sub-endocardium not matching any coronary artery distribution. The definitive treatment of GCM is a heart transplant. However, in patients with early diagnosis, immunosuppressive therapy has been shown to arrest the disease in 66% of patients - resulting in clinical remission sufficient enough for survival without the need for a heart transplant. CONCLUSIONS: GCM is an extremely rare and lethal disease. However, as demonstrated in this case, early diagnosis and initiation of immunosuppressive therapy can change the course of the disease and avoid the need for a heart transplant. Reference #1: Cooper LT, Berry GJ, Shabetai R. Idiopathic giant-cell myocarditis–natural history and treatment. Multicenter Giant Cell Myocarditis Study Group Investigators.N Engl J Med. 1997; 336:1860–1866. Reference #2: Riina Kandolin-Jukka Lehtonen-Kaisa Salmenkivi-Anne Räisänen-Sokolowski-Jyri Lommi-Markku Kupari.Diagnosis, Treatment, and Outcome of Giant-Cell Myocarditis in the Era of Combined Immunosuppression. Circulation: Heart Failure - 2013 DISCLOSURES: No relevant relationships by Xuming Dai, source=Web Response No relevant relationships by Sharmila Sarkar, source=Web Response