Perioperative Anticoagulant Use for Surgery Evaluation -2 (PAUSE-2) Study Patients Receiving a Direct Oral Anticoagulant (DOACs-Dabigatran, Rivaroxaban, Apixaban or Edoxaban) and Needing Elective High-Bleed-Risk Surgery or an Invasive Procedure

Perioperative Anticoagulant Use for Surgery Evaluation -2 (PAUSE-2) Study Patients Receiving a Direct Oral Anticoagulant (DOACs-Dabigatran, Rivaroxaban, Apixaban or Edoxaban) and Needing Elective High-Bleed-Risk Surgery or an Invasive Procedure: A Randomized Control Trial

PAUSE 2 study is a prospective, open-label, blinded-endpoint non-inferiority RCT of PAUSE vs. ASRA management in DOAC treated high risk patients with AF/VTE who need elective high bleed risk surgery/procedure and/or any procedure involving neuraxial anesthesia. The purpose of the PAUSE 2 study is to show that PAUSE management will be as safe (i.e., non-inferior) as ASRA management, with 95% of patients having low/undetectable pre-operative DOAC levels <30 ng/mL in each group., at the time of surgery/neuraxial.

As use of direct oral anticoagulants (DOACs) continues to increase so too will the need to manage such patients who require a surgery/procedure. Perioperative DOAC management is established and guideline supported in patients who need a low/moderate-bleed-risk surgery/procedure (e.g., hernia repair, colonoscopy), but there is uncertainty about managing high-risk patients who need a high-bleed-risk surgery (e.g., orthopedic, cardiac) or any neuraxial (i.e., spinal, epidural) anesthesia/procedure. The management of patients who are taking a DOAC (apixaban, dabigatran, edoxaban, rivaroxaban) and need a surgery/procedure is common, and will increase due to an ageing population and an associated increase in DOAC use. PAUSE-2 is applicable to approximately 96K patients/year in Canada, based on 1.6M prevalent patients with AF or VTE, of whom approximately 90% are taking a DOAC. Of these about 20% (approximately 288K) need perioperative management each year and approximately 1 in 3 (approximately 96K) are considered high-risk patients who need a high-bleed-risk surgery or neuraxial procedure. Perioperative DOAC management is of interest to a wide array of clinicians, including medical, surgical and anesthesia specialties, nurse practitioners, and pharmacists. In support of this statement, the Up-to-Date chapter on Perioperative Anticoagulation is in the top 0.6% (126th of 20,425) of all viewed chapters. However, guidelines provide weak recommendations on perioperative DOAC management in high-bleed-risk patients due to a lack of high-quality data.

There are two competing strategies for DOAC-treated patients who need a high-bleed-risk surgery/neuraxial:

1. PAUSE management is simple and easy to apply as patients having a high-bleed-risk surgery/neuraxial procedure interrupt DOACs for 2 days before and 2 days after surgery without heparin bridging or DOAC level testing. This approach is based on the Perioperative Anticoagulant Use for Surgery Evaluation (PAUSE) study of 3,007-patients with atrial fibrillation (AF) who had elective surgery/procedure.
2. ASRA management is more complex, requiring 72-120 hours DOAC interruption and, in selected patients, pre-operative heparin bridging and DOAC level testing. This management is based on recommendations from the American Society of Regional Anesthesia (ASRA) Guidelines, developed in 2015 and updated in 2018. ASRA's approach is very cautious so as to ensure no residual DOAC level at the time of a high-bleed-risk surgery/neuraxial procedure, using longer pre-operative DOAC interruption intervals.

Clinicians are divided on whether to use PAUSE or ASRA management for perioperative DOAC management in high-bleed-risk patients: Anesthetists strongly favor ASRA, as they consider it safer, in accordance with anesthesia society guidelines, and more prudent medico-legally than PAUSE. On the other hand, internists strongly favor PAUSE, which they consider more evidence-based than ASRA.

As shown in the table below, ASRA management is more complex (variable DOAC interruption) and harder to implement (DOAC testing, heparin bridging) than PAUSE (standard DOAC interruption, no DOAC testing/bridging). Though well-intentioned, ASRA management may not optimize patient safety and, indeed, may hinder adoption of standardized perioperative DOAC management.

Inclusion Criteria:

• Adults, age 18 years of age or greater, with AF/flutter (permanent, persistent or paroxysmal) or VTE (leg deep vein thrombosis or pulmonary embolism) that require a full (therapeutic)-dose DOAC regimen, appropriate for age and renal function, comprising one of (a) apixaban 2.5 mg or 5 mg bid; (b) dabigatran 110 mg or 150 mg bid; (c) edoxaban 30 mg or 60 mg daily; or (d) rivaroxaban 15 mg or 20 mg daily
• High-risk patient having an elective high-bleed-risk surgery or any elective surgery with neuraxial anesthesia (epidural, spinal, regional) or any deep nerve root block.

Exclusion Criteria:

• Indication for anticoagulation is unusual site thrombosis (e.g. splanchnic, cerebral, sinus, arm)
• Receiving a low-dose DOAC regimen used for secondary VTE prevention (e.g. rivaroxaban 10 mg daily, apixaban 2.5 mg bid) or another low-dose DOAC regimen (e.g. rivaroxaban 2.5 mg bid)
• CrCL<25mL/min (if on apixaban, edoxaban, rivaroxaban) or <30 mL/min (if on dabigatran)
• cognitive impairment or psychiatric illness that precludes reliable contact during follow up.
• Unable or unwilling to provide consent
• Previous participation in PAUSE 2