Impact of Factor Xa Inhibition on Coagulation, Platelet Reactivity, and Thrombosis in Patients with Peripheral Artery Disease.

BACKGROUND: The role of thrombin in vascular pathology is a focus of investigation. The incorporation of direct Factor Xa inhibition into practice patterns is based on its theoretical dual-pathway attenuation of both thrombin generation and platelet aggregation. However, quantification of the effect of direct anti-Xa medications on platelet function is not established. Thromboelastography with platelet mapping (TEG-PM) leverages dual-pathway metrics to provide comprehensive coagulation profiles. We evaluated the effects of direct oral anticoagulants (DOACs) on coagulation and platelet function profiles and correlate these data with postoperative major adverse limb events (MALEs) in patients with PAD. METHODS: We conducted a prospective study of patients undergoing lower extremity revascularization with serial perioperative TEG-PM analysis. Patients on DOACs were compared to those not on DOACs, and stratified by concurrent mono-antiplatelet or dual-antiplatelet regimens (MAPT/DAPT). Postoperative MALE was recorded and difference in antithrombotic regimens and TEG-PM analysis compared between groups. RESULTS: Four hundred seventy-one samples from 141 patients were analyzed. Twenty-nine point five percent were reflective of circulating DOAC therapy. Compared to MAPT alone, patients on DOAC + MAPT exhibited longer time to clot formation (R-time) [7.4 (±2.4) vs. 6.7 (±2.7); P < 0.02], but less platelet inhibition. Patients on DAPT exhibited greater platelet inhibition compared to either group [23.7 (±26.9) vs. 31.0 (±28.3) vs. 42.2 (±31.2); P < 0.01]. Patients who experienced MALE were more likely to be on DOAC therapy [43.8% vs. 22.0% P = 0.02]. Thromboelastography with platelet mapping analysis from patients who experienced MALE also demonstrated longer R-time [8.6 (±3.9 vs. 7.3 (±3.0); P = 0.05] and increased maximum clot amplitude (MA) [66.7 (±4.2) vs. 61.8 (±8.2); P = 0.001]. CONCLUSIONS: Direct oral anticoagulant therapy resulted in a prolonged R-time but had no impact on platelet inhibition. Patients who experienced MALE were more often on DOACs and demonstrated an increased R-time, but also showed greater platelet reactivity evident by increased MA, suggesting DOACs may not be effective at protecting against MALE. Further research comparing DOAC therapy to a DAPT approach may add clarity to emerging multimodal antithrombotic recommendations.

Management of the diabetic foot.

The increasing prevalence of diabatic foot ulcers (DFUs) is not only costly, but carries a large mortality burden. In this article, we discuss important traditional concepts in the management of DFUs and elaborate on how new technologies have expanded our ability to treat DFUs effectively. New supplies and wound care products have been developed to target the following traditional areas of focus: tissue, infection/inflammation, moisture, and edge. Offloading strategies have grown from standard orthotics or insoles to total contact casting and three-dimensional-printed orthotics to produce the optimum material stiffness for each patient. The concepts of pressure and temperature monitoring have led to the development of multiple devices that transmit continuous monitoring in real time, giving a dynamic picture of plantar stress and training patients in new walking strategies for self-offloading. Surgical approaches have also evolved from the classic surgical debridement and correcting deformities that cause friction to creation of acellular and bio-printed cellular skin substitutes that can be used for grafting. Surveillance and long-term follow-up with a multidisciplinary team have also changed in the face of smartphones and watches that allow patients to monitor themselves in real time with daily prompts and reminders to shape desired behaviors in between clinic visits. Modern technology is changing management of DFUs by expanding on traditional concepts and improving standard therapies.