Systemic Sclerosis Is Associated With Increased Inpatient Mortality in Patients Admitted for Atrial Fibrillation Analysis of the National Inpatient Sample

Purpose The aim of this study was to compare the outcomes of patients primarily admitted for atrial fibrillation (AFib) with and without a secondary diagnosis of systemic sclerosis (SSc). The primary outcome was inpatient mortality. Hospital length of stay (LOS), total hospital charges, odds of undergoing ablation, and electrical cardioversion were secondary outcomes of interest. Methods Data were abstracted from the National Inpatient Sample (NIS) 2016 and 2017 Database. The NIS was searched for adult hospitalizations with AFib as principal diagnosis with and without SSc as secondary diagnosis using International Classification of Diseases, Tenth Revision, Clinical Modification codes. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. Results There were over 71 million discharges included in the combined 2016 and 2017 NIS database. Of 821,630 AFib hospitalizations, 750 (0.09%) had SSc. The adjusted odds ratio for inpatient mortality for AFib with coexisting SSc compared with without coexisting SSc was 3.3 (95% confidence interval, 1.27-8.52; p = 0.014). Atrial fibrillation with coexisting SSc hospitalizations had similar LOS (4.2 vs 3.4 days; p = 0.767), mean total hospital charges ($40,809 vs $39,158; p = 0.266), odds of undergoing ablation (2.7% vs 4.2%; p = 0.461), and electrical cardioversion (12.0% vs 17.5%; p = 0.316) compared with without coexisting SSc. Conclusions Patients admitted primarily for AFib with a secondary diagnosis of SSc have more than 3 times the odds of inpatient death compared with those without coexisting SSc. Hospital LOS, total hospital charges, likelihood of undergoing ablation, and electrical cardioversion were similar in both groups.