We present a case of a patient with newly diagnosed cardiac sarcoidosis who presents initially with subtle changes in his very active lifestyle. What makes this diagnosis difficult is moving beyond the initial diagnosis of non-ischemic cardiomyopathy and further evaluating for the cause of the cardiomyopathy. Factors that suggested an infiltrative process included his young age as well as multiple ischemic and conduction abnormalities on EKG in the absence of coronary disease. The major implications of making this diagnosis are a change in prognosis as well as a shift in treatment strategy.
Sarcoidosis is a multi-system disease characterized by the formation of granulomas in various tissues throughout the body. The annual incidence of sarcoidosis in the United States has been estimated at 10.9 per 100,000 in whites and 35.5 per 100,000 in African Americans. In Europe, however, Scandinavians have the highest incidence rates at 50 to 60 cases per 100,000(1). Cardiac involvement is considered rare and occurs in about 2% of cases. However that figure may be higher as some cases of cardiac sarcoidosis are an asymptomatic accompanying feature of extra-cardiac involvement(2). Cardiac involvement can be present in the absence of any abnormality on standard cardiac testing.
Cardiac MRI is a useful tool in evaluating for an underlying disorder when a diagnosis of non-ischemic cardiomyopathy is made(3). MRI finding are suggestive of an infiltrative process should prompt an endomyocardial biopsy to verify the diagnosis. The finding of non-caseating granulomas on endomyocardial biopsy is virtually pathognomonic for the diagnosis of cardiac sarcoidosis however endomyocardial biopsy may frequently be negative as granulomas can be intermittently dispersed throughout the myocardium(4).
These granulomas cause inflammation and subsequently scar, which are believed to be the source of ventricular arrhythmias which are frequently seen in sarcoidosis and often cause sudden cardiac death. For this reason, many advocate for an aggressive approach in placing an ICD, especially if a pacemaker is already indicated given conduction abnormalities(1). Randomized controlled trials are lacking in treatment strategies, however, high dose steroids are the mainstay of treatment and are meant to reduce the inflammatory reaction caused by the granulomas and reduce scarring(5). Ultimately, heart transplantation is also a consideration.
Comment by Randall Starling, MD, MPH: MRI is a valuable too used to evaluate patients with non-ischemic cardiomyopathy. Abnormal findings on cardiac MRI can direct the need for endomyocardial biopsy which is only used in select cases depending on clinical features and data(6). In this case of non-ischemic cardiomyopathy the abnormal MRI led to a heart biopsy that yielded a definitive diagnosis of cardiac sarcoid. After further evaluation including a thoracic and total body PET we initiated treatment with immunosuppression for sarcoid. This case demonstrates the important role of cardiac MRI in leading us to a definitive diagnosis of cardiac sarcoid. Cardiac MRI is considered an essential component when evaluating patients with nonischemic cardiomyopathy.
- Kim JS, Judson MA, Donnino R, et al: Cardiac Sarcoidosis. Am Heart J 2009;157:9-21.
- Dubrey SW, Falk RH: Diagnosis and Management of Cardiac Sarcoidosis. Progress in Cardiovascular Disease 2010;52:336-346.
- Steel KE, Kwong RY: Application of Cardiac Magnetic Resonance Imaging in Cardiomyopathy. Current Heart Failure Reports 2008;5:128-135.
- Ardehali H, Howard DL, Hariri A, et al: A positive endomyocardial biopsy result for sarcoid is associated with poor prognosis in patients with initially unexplained cardiomyopathy. Am Heart J 2005;150:459-463.
- Sugisaki K, Yamaguchi T, Nagai S, et al: Clinical characteristics of 195 Japanese sarcoidosis patients treated with oral corticosteroids. Sarcoidosis Vasc Diffuse Lung Dis 2003;20:222-226.
- Cooper LT, Baughman KL, Feldman AM, et al. The role of endomyocardial biopsy in the management of cardiovascular disease: a scientific statement from the American Heart Association; American College of Cardiology; European Society of Cardiology. Circulation. 2007 Nov 6;116(19):2216-33.