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.