Abstract
Background
Heparin-induced thrombocytopenia (HIT) is a severe immune-mediated complication of heparin exposure, leading to negative consequences after total hip (THA) and knee arthroplasty (TKA). However, the incidence and risk factors of HIT remain to be elucidated. This study aimed to identify the incidence, outcomes, and risk factors of HIT after THA and TKA.
Methods
A retrospective study was conducted using the National Inpatient Sample (NIS) database from 2005 to 2014. The incidence and outcomes of HIT after THA or TKA were documented. Logistic regression analysis was performed to identify the postoperative HIT risk factors.
Results
A total of 593,045 patients who underwent THA and 1,228,707 patients who underwent TKA were identified. The cumulative incidences were 0.02% and 0.01%, respectively. The HIT group presented significantly higher Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI) scores, longer hospital stays (LOS), and higher medical costs. HIT led to a significantly higher mortality rate after THA (2.17% vs. 0.16%, p =0.0091). Although not statistically significant, the HIT mortality rate after TKA was also increased (0.58% vs. 0.07%; p =0.1178). In THA, the risk factors of HIT were racial minority, AIDS, pulmonary circulation disorders (PCD), psychoses, and hypertension; the protective factors were large-scale and teaching hospitals. In TKA, the HIT risk factors were racial minority, PCD, and weight loss. Teaching hospitals served as protective factors.
Conclusions
The incidence of HIT after THA and TKA is relatively low; however, HIT significantly increases inpatient mortality, LOS, and medical cost. Therefore, HIT warrants considerable attention and further investigation.