The role of platelet hyperreactivity in venous thromboembolism after total knee arthroplasty in elderly population without pharmacologic prophylaxis: A single‐center study

Abstract

Introduction While it is suggested that platelet hyperreactivity plays a role in the arterial thrombi, its link with venous thromboembolism (VTE) is not well defined. Aggregometry using low concentrations of agonists is proposed as a reliable method to detect hyperreactivity. The aim of this study was to examine whether platelet hyperreactivity affects the development of VTE after total knee arthroplasty (TKA). Methods Total 150 elderly patients without VTE history were enrolled. Mechanical prophylaxis was used for VTE after TKA. We performed platelet aggregation using Chrono‐log (Chrono‐log Corporation, USA) in the presence of low concentrations of ADP (1.0 μmol/L) and epinephrine (0.4, 1.0 μmol/L), and measured maximal aggregation (%). Results At 0.4 μmol/L epinephrine, 69.3%, 15.3%, and 15.3% displayed low (<40%), moderate (40‐60%), and high (>60%) levels of aggregation, respectively. The proportion of high level of aggregation was 36.7%, 30.7% at 1.0 μmol/L of epinephrine and ADP, respectively. The incidence of VTE was higher in the moderate/high aggregation group (10/46, 21.7%) than in the low aggregation group (1/104, 1.0%) at 0.4 μmol/L epinephrine (P < 0.0001). In predicting postoperative VTE, sensitivity and specificity of ≥40% aggregation at 0.4 μmol/L epinephrine were 90.9% and 74.1%. Higher mean platelet volume and lower volume of blood loss were seen in the high aggregation group than in the low aggregation group. Conclusion Aggregation response to 0.4 μmol/L epinephrine is an optimal assay to classify platelet activity. Platelet hyperreactivity may increase the risk of postoperative VTE in an elderly population, and can be an indication of pharmacologic prophylaxis.

Effect of age on the functioning of hemostasis system during hip joint endoprosthesis

“…Already at the pre-operative stage, the activity of hemocoagulation was increased in patients with osteoarthritis [24,25]. Traumatic surgeries involve extensive tissue damage, this in turn stimulates the powerful activation of thrombin formation at the site of damage.…”

An Update on Venous Thromboembolism Rates and Prophylaxis in Hip and Knee Arthroplasty in 2020

“…Together, these molecules can trigger tissue factor (TF) and thrombin expression, the formation of neutrophil extracellular traps, and platelet activation, subsequently initiating the clotting cascade and thrombosis [ 23 , 24 , 25 ]. In addition, some patients may be predisposed to platelet hyperreactivity, further increasing their risk [ 26 ]. Stasis can contribute to hypercoagulability by increasing the concentration of pro-thrombotic factors at the sites of injury [ 27 ].…”