A positive endomyocardial biopsy result for sarcoid is associated with poor prognosis in patients with initially unexplained cardiomyopathy

Background Sarcoidosis is a systemic granulomatous disorder of unknown etiology. In patients with cardiomyopathy, the diagnosis of sarcoidosis has important treatment implications. We studied the prognostic implications of a cardiac biopsy diagnosis of sarcoidosis in patients with unexplained cardiomyopathy. Methods We evaluated 1235 patients with unexplained cardiomyopathy who underwent endomyocardial biopsy (EMBx) between 1982 and 1997 at the Johns Hopkins Hospital. Twenty-eight patients were referred with a clinical diagnosis of sarcoidosis. Results Seven of these 28 patients (25%) plus 3 more with other initial diagnoses had sarcoidosis on heart biopsy. Of these 10 patients, 3 (30%) died with a median survival time after biopsy of 0.69 years. Of the remaining 21 patients with a clinical diagnosis of sarcoidosis, 20 had negative biopsy results for sarcoidosis and 7 (35%) died with a median survival time of 2.34 years. The odds of death within 1, 2, and 3 years were higher for those with than for those without an EMBx-proven cardiac sarcoid (crude OR 4.75 [P = .23], 8.1 [P = .09], and 1.28 [P = .78], respectively), but the differences failed to reach significance at the .05 level. However, the difference in the odds of death within 2 years did achieve marginal significance. Conclusions Only a quarter of patients with cardiomyopathy and clinical diagnosis of sarcoid have a noncaseating granuloma on EMBx. Of those with a clinical diagnosis of sarcoidosis, heart biopsy results that are positive for sarcoidosis appear to be associated with a shorter median survival time than heart biopsy results that are negative for sarcoidosis. Finally, a noncaseating granuloma on EMBx is a rare finding in patients with cardiomyopathy without a history of sarcoidosis.