Perioperative Anticoagulant Use for Surgery Evaluation -Virtual Visit (PAUSE-Virtual)

The Clinical Problem: The management of patients who are taking warfarin or a direct oral anticoagulant (DOAC) and need an elective surgery/procedure is a common and important clinical problem: (i) ~200,000 patients/yr are assessed in Canada for such management and this will increase due to an ageing population and an increase in anticoagulant use; and (ii) if anticoagulants are not managed carefully, with evidence-based protocols, patients can be exposed to an increased risk for disabling stroke if anticoagulant interruption is too long or life-threatening bleeding if interruption is too short.

The Healthcare Delivery Problem: Perioperative management of anticoagulant therapy has been traditionally done in an in-person setting where patients receive instructions about when to stop and restart anticoagulants and, if needed, to receive teaching to self-administer heparin bridging. The COVID pandemic has upended this healthcare delivery model, necessitating virtual management by phone/video. Virtual patient care to manage perioperative anticoagulation has the potential to be an efficient and patient-friendly standard post-pandemic. However, to attain this objective, it must be reliably shown that virtually-administered, standardized, perioperative anticoagulation management is: (i) safe, with acceptably low rates of stroke and bleeding; (ii) easy to apply in practice; and (iii) acceptable to patients.

The foundation for this study is based on prior work by the investigator: (i) The investigator has led multicenter clinical trials (BRIDGE, PAUSE) that provide benchmarks for safe perioperative management of patients who are receiving warfarin or a DOAC; (ii) the management protocols from these trials were incorporated into a clinical decision tool that is available (cost-free) by Thrombosis Canada (www.thrombosiscanada.ca). This point-of-care app allows input of patient-specific information to manage individual patients with atrial fibrillation/flutter (AF) who are receiving warfarin or a DOAC and require an elective surgery/procedure. At the end of the assessment, a care-path summary is available as a PDF for clinicians and patients for downloading and printing.

The Opportunity: The pandemic has necessitated the adoption of virtual perioperative anticoagulant management but also has provided the opportunity to re-evaluate how such care can be safely delivered. Given that (i) perioperative anticoagulant interruption/resumption and heparin bridging protocols are standardized, and (ii) there is an easy-to-use, point-of-care, management app available, the investigator has a unique opportunity to apply evidence-informed protocols with user-friendly knowledge translation tools to assess the safety and acceptability to patients of virtual perioperative anticoagulant management.

The Solution: A prospective cohort study (non-RCT) assessing standardized virtual perioperative management in 2 cohorts of patients on warfarin or a DOAC who require an elective surgery/procedure.

Hypothesis & Postulates: (i) the investigator hypothesizes that virtual perioperative management will be safe for patient care, with 30-day postoperative rates of stroke/systemic embolism (SSE) ≤0.5% and major bleeding (MB) ≤1.5%. With a sample size of 847 patients in Cohort 1 and in Cohort 2, the investigator will have 90% power at the 95% level of significance to reject the null hypothesis that the observed rates are ≥1.5% for SSE and ≥3% for MB in each cohort. (ii) The investigator postulates (a) that virtual management will be as safe as in matched historical control groups who received benchmark in-person management, (b) that virtual management will reduce healthcare costs and costs to patients, and (c) that patients will be satisfied with virtual management and will be willing to receive this methods of healthcare delivery post-pandemic.

Significance: PAUSE-Virtual will shift perioperative anticoagulant management from a resource-intensive in-person model to a patient-friendly virtual model, establishing a standard-of-care option for 200,000 patients/yr in Canada. The investigator is a leading group in perioperative anticoagulant management worldwide, having done the landmark BRIDGE1 and PAUSE2 trials. There is no other research group (that the investigator knows of) that will do this trial, and it will not be funded by industry (no commercial interest).