Introduction: Literature regarding outcomes and predictors of complications secondary to infective endocarditis (IE) is limited. We aimed to study the outcomes and predictors of complications of IE.

Methods: Data from a national emergency department sample, which constitutes 20% sample of hospital-owned emergency departments in the USA, were analyzed for hospital visits for IE. Complications of endocarditis were obtained by using ICD codes. Multivariable generalized linear method was used to evaluate predictors of in-hospital mortality and complications.

Results: Out of 255,838 adult IE patients (mean age 60.3 ± 20.1 years, 48.5% females), 97,803 (38.2%) patients developed one or more major complications. The major complications were cardiovascular system complications [57,900 (22.6%)], neurologic [42,851 (16.7%)] complications, and renal [16,236 (6.4%)] complications. These included cardiogenic shock [3873 (1.5%)], septic shock [25,798 (10.1%)], acute heart failure [35,602 (14%)], systemic thromboembolism (STE) [21,390 (8.36%)], heart block [11,430 (4.47%)], in-hospital dialysis [2880 (1.1%)], and disseminated intravascular coagulation (DIC) [2704 (1.1%)]. Patients with complicated IE had risk of mortality (adjusted RR 1.12, 95% CI 1.11-1.13, p < 0.001). The complications strongly associated with mortality were septic shock (RR 1.29, 95% CI 1.27-1.30, p < 0.001), cardiogenic shock (RR 1.24, 95% CI 1.20-1.29, p < 0.001), DIC (RR 1.4, 95% CI 1.35-1.46, p < 0.001), and STE (RR 1.07, 95% CI 1.05-1.08, p < 0.001). Staphylococci were the predominant causative organisms (30.8%) among the complicated IE subgroups with higher associated mortality (42.8%). The main predictors of complications from IE were congenital heart disease, history of congestive heart failure, high Elixhauser comorbidity profile, staphylococcal infection, and fungal infections. The prevalence of cardiogenic shock increased over the study years from 1.13 to 1.98% (p-trend 0.04).

Conclusion: Complicated IE is not uncommon and is associated with significant mortality. Staphylococcal infections were associated with high mortality rates. There has been an increasing trend of cardiogenic shock among IE patients across the US. Further research is needed to improve the outcomes of complicated endocarditis.