Approximately 5% of patients with sarcoidosis have clinically manifest cardiac involvement. Clinical features of Cardiac Sarcoidosis are dependent on the location, extent, and activity of the disease. First line therapy is usually with prednisone and this is recommended based on clinician experience, expert opinion and small observational cohorts. There are no published clinical trials in cardiac sarcoidosis and multiple experts in the field have called for randomized clinical trials to answer important patient care questions. Corticosteroid are associated with multiple adverse effects including hypertension, diabetes, weight gain, osteoporosis, and increased risk of infections. In contrast Methotrexate is generally well tolerated and is increasingly used in other forms of sarcoidosis.

The Cardiac Sarcoidosis Multi-Center Randomized Controlled Trial (CHASM CS-RCT; NCT03593759) is a multicenter randomized controlled trial designed to evaluate the optimal initial treatment strategy for patients with active cardiac sarcoidosis. We hypothesize that (1) a low dose prednisone/methotrexate combination will have non-inferior efficacy to standard dose prednisone and that (2) the low dose prednisone/ methotrexate combination will result in significantly better quality of life than standard dose prednisone, as a result of reduced burden of side effects.

Eligible study subjects will have active clinically manifest cardiac sarcoidosis presenting with one or more of the following clinical findings: advanced conduction system disease, significant sinus node dysfunction, non-sustained or sustained ventricular arrhythmia, left ventricular dysfunction or right ventricular dysfunction. Subjects will be randomized in a 1:1 ratio to prednisone 0.5 mg/kg/day for 6 months (maximum dose 30 mg daily) OR to prednisone 20 mg daily for 1 month, then 10 mg daily for 1 month, then 5 mg daily for one month then stop AND methotrexate 15–20 mg once weekly for 6 months. The primary endpoint is summed perfusion rest score on 6-month PET (blinded core-lab review). The summed perfusion rest score is measure of myocardial fibrosis/scar. The design is non-inferiority with a sample size of 97 per group.

Given the multiorgan system potential adverse side effects of prednisone, proving noninferiority of an alternate regimen would be sufficient to make the alternative compare favorably to standard dose steroids. This is the first ever clinical trial in cardiac sarcoidosis and thus in addition to the listed goals of the trial, we will also establish a multi-center, multinational cardiac sarcoidosis clinical trials network. Such a collaborative infrastructure will enable a new era of high quality data to guide physicians when treating cardiac sarcoidosis patients.