Compliance to perioperative anticoagulation protocols in elderly patients undergoing elective orthopedic procedures: a retrospective observational cohort study on 548 patients.

Background: Compliance with perioperative anticoagulation guidelines is essential to minimize bleeding and thromboembolic risks in patients undergoing surgery. Compared to vitamin-K antagonists (VKAs), perioperative management of direct oral anticoagulants (DOACs) contains fewer steps. Therefore, we hypothesized that noncompliance with guidelines in VKA users is higher than in DOAC users. The primary aim of our study was to investigate the difference in noncompliance to perioperative anticoagulant management guidelines between elderly patients using VKAs versus those using DOACs. The secondary aim was to determine the difference in occurrence of conflicting information communicated to the patients and the difference in incidence of coagulation-related adverse events.

Methods: This retrospective non-controlled observational cohort study examined elderly patients undergoing elective orthopedic surgery in a teaching hospital in the Netherlands. All patients undergoing elective orthopedic surgery between 1 May 2016 and 1 January 2020, aged 70 years and over, using VKAs or DOACs were selected. Nonelective surgeries were excluded. The primary outcome was the noncompliance to perioperative anticoagulant management guidelines. Secondary outcomes were missing or conflicting information on anticoagulation management communicated to the patient and coagulation-related adverse events. For continuous data, the unpaired T-test was used and for categorical data, the chi-square test.

Results: In patients using VKAs, noncompliance to one of the steps of perioperative anticoagulation management was 81%, compared to 55% in patients using DOACs (p < 0.001). In most cases, VKAs or DOACs were interrupted for longer than recommended. In 13% of patients using a VKA with perioperative bridging, bridging was not conducted as recommended in the guidelines. In 13% of patients using a DOAC, a low-molecular-weight heparin (LMWH) was prescribed while a DOAC had already been restarted postoperatively. VKA users received conflicting information about perioperative anticoagulation management more often than DOAC users (33% versus 20%; p < 0.001). No difference was seen in postoperative coagulation-related complications.

Conclusion: Guidelines compliance in DOAC users is higher than in VKA users. Clinical decision support to help in selecting the right interruption interval in DOAC users, simplified standardized perioperative management, good coordination of instructions given to patients, and familiarity with updated guidelines are important in reducing noncompliance.