Prevalence, incidence, and clinical features of cardiac involvement in patients with pulmonary sarcoidosis.

Background: The epidemiology and characteristics of cardiac involvement in patients with pulmonary sarcoidosis remain unclear. We aimed to determine the prevalence, incidence, and clinical features of cardiac sarcoidosis in patients with pulmonary sarcoidosis.

Methods: The characteristics of patients with biopsy-proven pulmonary sarcoidosis were retrospectively evaluated. Cardiac sarcoidosis was diagnosed via evaluations, including F-fluorodeoxyglucose positron emission tomography at the time of diagnosis of pulmonary sarcoidosis and during follow-up. Characteristics of patients with and without cardiac complications were compared.

Results: In total, 438 patients with pulmonary sarcoidosis were included, of which 40 (9.1 %) were diagnosed with cardiac sarcoidosis at the time of diagnosis of pulmonary sarcoidosis. During the follow-up period, 14 patients (4 %) developed cardiac complications (0.0075/person-years). Electrocardiographic abnormalities were the most common findings leading to the diagnosis of cardiac sarcoidosis (85 %). Compared to patients without cardiac involvement, those with cardiac sarcoidosis had lower serum angiotensin converting enzyme concentration [19.9 (15.5-25.1) vs. 17.4 (12.6-23.8) U/L)], higher rates of kidney complications (3 vs. 13 %), fewer ocular complications (78 vs. 17 %), and lower lymphocyte levels [35.8 (18.6-53) vs. 25.1 (14.2-38.2)%] and CD4/CD8 ratios [4.8 (3.1-7.5)% vs. 3.9 (1.8-6)%] in bronchoalveolar lavage fluid analysis.

Conclusion: At the time of diagnosis of pulmonary sarcoidosis, cardiac complications occurred in approximately 10 % of the patients and developed in 0.0075/person-year during follow-up. Low serum angiotensin converting enzyme concentration, lymphocyte level and CD4/CD8 ratio in the bronchoalveolar lavage fluid may be unique features of patients with cardiac sarcoidosis.