Survival in biopsy-proven cardiac sarcoidosis is similar to survival in lymphocytic myocarditis and dilated cardiomyopathy

While long-term survival in biopsy-proven lymphocytic myocarditis (LM) has been shown to be similar to dilated cardiomyopathy (DCM), the relative, long-term prognosis of cardiac sarcoidosis (CS) remains controversial. Subjects with endomyocardial biopsy (EMB)-diagnosed LM (n=27), DCM (n=58) from the Mayo Clinic were compared to subjects with EMB-diagnosed CS from a multicenter registry (n=29). A cardiac pathologist confirmed the diagnosis in all cases. All cases of CS had epithelioid granulomas on the biopsy specimens. Ten of the LM patients had borderline myocarditis and 17 had active myocarditis by the Dallas Criteria. Subjects with CS had higher rates of ventricular tachycardia, heart block, and syncope. Despite this, survival of patients with CS diagnosed was similar to that of patients with LM and DCM. The presence of ventricular tachycardia, heart block, or syncope in a patient with undiagnosed cardiomyopathy increased the likelihood of cardiac sarcoidosis in our population.