Prevalence and outcomes of heparin-induced thrombocytopenia in hospitalized patients with venous thromboembolic disease: Insight from national inpatient sample

Objective: The mainstay of therapy for patients with venous thromboembolic disease (VTE) is anticoagulation. In the inpatient setting, majority of these patients are treated with heparin or low molecular weight heparin. The prevalence and outcomes of heparin-induced thrombocytopenia (HIT) in hospitalized patients with venous thromboembolic dis-ease (VTE) is unknown.Methods: This nationwide study identified patients with VTE from the National Inpatient Sample database between January 2009 and December 2013. Among these patients, we compared in-hospital outcomes of patients with and without HIT using a propensity score-matching algorithm. The primary outcome was in-hospital mortality. Secondary outcomes included rates of blood transfusions, intracranial hemorrhage, gastrointestinal bleed, length of hospital stay, and total hospital charges.Results: Among 791,932 hospitalized patients with VTE, 4948 patients (0.6%) were noted to have HIT (mean age, 62.9 616.2 years; 50.1% female). Propensity-matched comparison showed higher rates of in-hospital mortality (11.01% vs 8.97%; P < .001) and blood transfusions (27.20% vs 20.23%; P < .001) in patients with HIT compared with those without HIT. No significant differences were noted in intracranial hemorrhage rates (0.71% vs 0.51%; P > .05), gastrointestinal bleed (2.00% vs 2.22%; P > .05), length of hospital stay (median, 6.0 days; interquartile range [IQR], 3.0-11.0 vs median, 6.0 days; IQR, 3.0-10.0 days; P > .05), and total hospital charges (median, $36,325; IQR, $17,798-$80,907 vs median, $34,808; IQR, $17,654-$75,624; P > .05).Conclusions: This nationwide observational study showed that 0.6% of hospitalized patients with VTE in the United States have HIT. The presence of HIT was associated with higher in-hospital mortality and blood transfusion rates compared with those without HIT. (J Vasc Surg Venous Lymphat Disord 2023;11:723-30.)