Foundation for Sarcoidosis Research Clinical Studies Network (FSR-CSN): Northwestern Medicine Program

Although it has been reported that only 5% of North American patients with sarcoidosis exhibit clinical evidence of cardiac involvement (1), in autopsy series cardiac sarcoidosis has been found in over 25% of cases (2, 3). Moreover, cardiac involvement is reported to account for 13-25% of disease-related deaths (2, 3). Recent studies utilizing cardiac magnetic resonance imaging (MRI) and cardiac positron emission tomography (PET) scanning have identified cardiac involvement in 26-55% of sarcoidosis patients (4), although many of these did not have cardiac symptoms at the time of diagnosis. The clinical manifestations of cardiac sarcoidosis encompass conduction system abnormalities, including left and right bundle branch block, bifascicular block, second degree and third degree heart block; supraventricular tachyarrhythmias; ventricular tachyarrhythmias; sudden cardiac death; non-ischemic cardiomyopathy; and congestive heart failure. It is generally believed that immunosuppressive therapy with corticosteroids and/or other agents is strongly indicated for cardiac sarcoidosis with any of the foregoing abnormalities. This is supported by retrospective data, which suggest better outcomes in patients treated with corticosteroids as compared to those not treated (5, 6). In a recent retrospective analysis, Padala et al found that early initiation of steroid therapy (within one month of the diagnosis of cardiac sarcoid) was associated with a greater likelihood of improvement in left ventricular (LV) ejection fraction (EF) and lesser chance of recurrent ventricular tachyarrhythmias, as compared to later initiation of therapy (7). Zhou et al also recently published their experience in 73 patients with cardiac sarcoidosis followed for a median of 8.8 years (8). In this cohort, all of whom were treated with corticosteroids or other immunosuppressive agents, 5- and 10-year survival rates were 95.5% and 93.4%, respectively, and age ≥ 46 years and lack of an implanted pacemaker or defibrillator were identified as independent predictors of mortality. While these retrospective studies provide certain insights, it is notable that no randomized controlled study of corticosteroids or any other therapy for cardiac sarcoidosis has ever been published. Thus, there is no high quality evidence upon which to base decisions about the intensity and duration of immunosuppressive therapy for sarcoidosis involving the heart.