BACKGROUND Sarcoidosis is a multi-systemic granulomatous inflammatory disorder. In the setting of cardiac involvement, clinical manifestations include ventricular arrhythmias, high-grade atrioventricular block (AVB) and heart failure (HF). The impact of HF in patients with sarcoidosis has not been established from real-world data. METHODS Patients admitted with sarcoidosis from 2010-2019 were identified from the Nationwide Readmissions Database. Those with ischemic heart disease were excluded. Sarcoidosis patients without HF were propensity matched for age, gender and Charlson comorbidity index and compared to patients with HF. Clinical characteristics, length of stay (LOS), adjusted healthcare-associated costs (HAC), 90-day readmission and 90-day mortality was observed. RESULTS During the 10-year study period, 97,961 patients (median age 63 [54-71] years, 37.9% male) with a diagnosis of sarcoidosis were hospitalized (35.9% with HF and 64.1% without HF). On index admission, HF patients had a higher prevalence of AVB (3.3% vs 1.4%, p<0.0001), ventricular tachycardia (6.5% vs 1.3%, p<0.0001), ventricular fibrillation (0.4% vs 0.1%, p<0.0001) and atrial fibrillation (22.1% vs 7.5%, p<0.0001). The median LOS (4 [3-7] vs. 4[2-6] days, p<0.0001) was similar but median HAC (US$ 9,954.5 [5,934.7-18,128.8] vs. 8,828.3 [5,303.1-15,384.9], p<0.0001) during the index admission were higher in HF patients. The LOS and HAC were greater in HF patients on 90-day readmission. HF patients were significantly more likely to be re-admitted within 90 days [adjusted all-cause readmissions (HR [95% CI: 1.28 [1.25 – 1.31], p<0.0001), atrial fibrillation (HR 1.35 [1.05-1.75], p=0.02), acute HF (HR 10.77 [9.45 – 12.16], p<0.0001) and ventricular tachycardia/ventricular fibrillation (HR 2.55 [1.69 – 3.85], p<0.0001)]. Adjusted inpatient mortality at readmission was also higher in HF patients (5.1% vs. 3.8%, p<0.0001). CONCLUSION The presence of HF in hospitalized sarcoidosis patients is associated with an increased prevalence of conduction disorders, ventricular arrhythmias and atrial fibrillation. HF patients had greater costs, readmissions and mortality at 90-days. What is known? What the study adds? ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research did not receive any funding from any source. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: N/A I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All manuscript authors confirm the following: 1) The paper is not under consideration elsewhere 2) None of the paper's contents have been previously published 3) All authors have read and approved the manuscript 4) All potential conflicts of interest have been disclosed.