A 48-year-old male with no known medical history came to the emergency room reporting worsening dyspnea on exertion. ECG is without ischemic changes and high-sensitivity troponin is modestly elevated at 68 ng/L. He is quickly admitted to the cardiac intensive care unit in advanced cardiogenic shock and with recurrent ventricular tachycardia despite diuretics, inodilators, lidocaine, and amiodarone. Emergent myocardial biopsy at time of initiation of mechanical support reveals lymphocytes and multinucleated giant cells.
Which of the following agents is an appropriate treatment?A. Azathioprine, cyclosporine, and corticosteroids
Correct Answer: A
Giant cell myocarditis is a type of myocarditis characterized by cardiovascular collapse, with frequent ventricular arrhythmias and/or advanced atrioventricular heart block. The gold standard for diagnosis is endomyocardial biopsy. Although given the potential for sampling bias, a negative first biopsy with a high clinical suspicion should warrant consideration for repeat biopsy. Cardiac MRI and cardiac PET scan can help identify affected areas and can assist with biopsy planning, increasing the yield. In giant cell myocarditis, pathology reveals lymphocytic infiltrate with multinucleated giant cells. Beyond the initial presentation, patients with giant cell myocarditis are at high risk for malignant ventricular arrhythmias.
Therapeutically, there is no clear mortality benefit for the use of IVIG in patients with giant cell myocarditis. Literature suggests improved survival in patients receiving immunosuppresive therapy with multiple agents: azathioprine, cyclosporine, antithymocyte globulin, methotrexate, mycophenolate mofetil, and glucocorticoids. IVIG or glucocorticoids alone is less effective. NSAIDs are not helpful in myocarditis and may worsen heart failure. The patient with giant cell myocarditis should also be evaluated for mechanical circulatory support.