Impact of comorbidities and organ damage on hospital admissions and mortality in patients with sarcoidosis: an observational study from the Spanish National Registry

Advanced lung disease, cardiovascular disease (CVD), infections, malignancies, and thromboembolic disease (TED) determine the mortality of patients with sarcoidosis. Our objective was to evaluate the main causes of admission and in-hospital mortality in patients with sarcoidosis in Spain. A retrospective and observational analysis of the National Registry of Hospital Discharges (RAE-CMBD) of patients admitted with a diagnosis of sarcoidosis between 2016 and 2021 was performed. A total of 18,887 admissions of patients with sarcoidosis were identified. The main causes of admission were infection (21%), sarcoidosis itself (16.4%), CVD (12.7%), and malignancies (7.1%). Overall, 892 (4.7%) patients died, mainly from infection (32.1%), CVD (16.3%) and neoplasms (12.4%), with case fatality rates of 7.2%, 6% and 8.3%, respectively. Factors associated with higher in-hospital mortality were Charlson comorbidity index (OR 1.30 95%CI 1.27-1.34), sarcoidosis pulmonary involvement (OR = 1.20, 95%CI 1.04-1.38), pulmonary fibrosis (OR 2.07; 95%CI 1.52-2.81) and CVD (OR 1.56; 95%CI 1.26-1.95), infection (OR 2.37; 95%CI 1.97-2.84), malignancies (OR 1.77; 95%CI 1.38-2.27) and TE-related admissions (OR 2.1, 95%CI 1.21-3.76). The main determinants of hospital admissions and mortality in patients with sarcoidosis are infections, CVD, neoplasm, VTE, pulmonary fibrosis, and a high comorbidity burden. While sarcoidosis itself is a common cause of admission, it is rarely the cause of death. Prevention of infections, VTE, and neoplasm, along with control of cardiovascular risk factors, may help reduce mortality in these patients.