Japanese AntibaCterial drug maNagemEnt for cardiac Sarcoidosis Trial

INTERVENTION: combination therapy group: Prednisolone; Predonisolone start from 30mg/day and continue same dose for one month. After one month, prednisolone decrease 25mg, 20mg, 15mg, 10mg every 2‐4 weeks. Finally, maintenance dose of predonisolone is 7.5mg. Antimicrobial agent; Clarithromycin start from 400mg/day for 24weeks. Doxycycline start 100mg/day for 22 weeks after 2 months of clarithromycin therapy. Prednisolone; Predonisolone start from 30mg/day and continue same dose for one month. After one month, prednisolone decrease 25mg, 20mg, 15mg, 10mg every 2‐4 weeks. Finally, maintenance dose of predonisolone is 7.5mg. CONDITION: Cardiac sarcoidosis PRIMARY OUTCOME: the change of SUV level from baseline in FDG‐PET/CT examination (6 months after study enroll) SECONDARY OUTCOME: the frequency of steroid dose increasing (12 months after study enroll) INCLUSION CRITERIA: Cardiac sarcoidosis patient who have positive finding of FDG‐PET and/or Ga scintigram and indication of steroid therapy.