Histologic diagnostic rate of cardiac sarcoidosis: Evaluation of endomyocardial biopsies

Background An early diagnosis of cardiac sarcoidosis is important, particul arly when considering the need for administering corticosteroid therapy. Ho wever, no reports are available on the success rate of diagnosis on the bas is of biopsy findings in patients with cardiac sarcoidosis. This study inve stigated the diagnostic success rate of histologic evaluation of endomyocar dial biopsy specimens in patients with this disease. Methods and Results Right ventricular endomyocardial biopsy was performed i n 26 patients in whom cardiac sarcoidosis was strongly suspected according to the Diagnostic Criteria of Sarcoidosis, plus abnormalities on the electr ocardiogram, cardiac radionuclide images, or in left ventricular wall motio n. A mean of 4.0 sites were sampled per patient. In each case we determined whether a definitive diagnosis of cardiac sarcoidosis could be made histol ogically. Noncaseating granulomas were found in only 5 (19.2%) of the 26 ca ses, thus permitting a histologic diagnosis of cardiac sarcoidosis. A histo logic diagnosis was made in 4 (36.4%) of 11 patients who exhibited a dilate d cardiomyopathy-like clinical picture, in contrast to only 1 (6.7%) of 15 patients in whom conduction disturbances were the major clinical feature an d whose left ventricular ejection fraction was within normal limits. Conclusions The diagnostic rate achieved with biopsy in cardiac sarcoidosis is low; the patients with sarcoidosis and evidence of significant cardiac involvement should be treated for cardiac sarcoidosis despite negative myoc ardial biopsies for this disease.