Purpose: Oral anticoagulant therapy (OAT) patients have international normalized ratio (INR) safety windows for oral surgery, the lower limit of which is determined by the thromboembolic risk, with the upper limit typically 3.0. We sought to assess whether these limits will also be true with comorbidities that favor bleeding, such as diabetes, liver disease, and chronic renal failure.
Materials and methods: The study was designed for 500 consecutive extractions. Patients with an INR greater than 3.0 were switched to heparin and used as controls. The primary outcome was the incidence of bleeding with the need for reoperation, in connection with 3 principal predictors: the INR, reasons for OAT, and comorbidity type. Continuous variables were analyzed using the Mann-Whitney U test and categorical variables using χ2 or Fisher's exact test. Statistical significance was set at P < .05. The reliability of the INR as a bleeding predictor was assessed using receiver operating characteristic (ROC) curves.
Results: Extractions in patients receiving OAT without comorbidities had a success rate of 99.7% against severe bleeding. Despite equivalent INR values, patients with comorbidities had a significantly lower rate (81.3%, P < .001). For these patients, the ROC curve procedure indicated lower INR upper limits, 2.8 for mechanical heart prosthesis subjects and 2.3 for all others. Among the comorbidities, diabetes was associated with the greatest frequency of bleeding (31%) compared with liver disease (15%) and kidney failure (11%).
Conclusions: Patients with comorbidities should be advised to bring their INR within narrower safety windows (upper limit of 2.5 to 2.8 for mechanical prosthesis and 2.0 to 2.3 otherwise) or be switched to heparin. Alternatively, we propose applying to the socket, a platelet-rich growth factor preparation to foster hemostasis.
Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.