What are the preoperative clearance requirements for a low-risk patient undergoing elective surgery with well-controlled hypertension, diabetes, or hyperlipidemia, and taking medications such as aspirin, warfarin, or novel oral anticoagulants (NOACs)?

Preoperative Clearance for Low-Risk Patients

For low-risk patients with well-controlled chronic conditions (hypertension, diabetes, hyperlipidemia) undergoing elective surgery, minimal preoperative testing is required, with management focused primarily on appropriate timing of anticoagulant/antiplatelet medication interruption based on surgical bleeding risk.

General Approach to Low-Risk Patients

• History and physical examination remain the cornerstone of preoperative assessment, focusing specifically on cardiovascular risk factors, functional capacity, and current medication regimen 1, 2, 3
• Routine preoperative laboratory testing is not indicated for asymptomatic patients with well-controlled chronic conditions undergoing low-risk procedures 2, 3, 4
• The 30-day preoperative history and physical requirement is increasingly viewed as low-value for truly low-risk ambulatory procedures, with many surgeons describing it as "unnecessary" or "just checking a box" 5

Management of Antiplatelet Agents

Aspirin

• Continue aspirin perioperatively for most low-to-moderate bleeding risk procedures 1
• Stop aspirin 7 days before surgery only for high bleeding risk procedures (intracranial, spinal surgery) 1
• Resume aspirin postoperatively once adequate hemostasis is achieved 1

Management of Warfarin

Preoperative Interruption

• Stop warfarin 5-6 days before surgery to allow INR to normalize 1
• Check INR on day of procedure; proceed if INR ≤1.5 1
• If INR 1.5-1.8, consider low-dose oral vitamin K (1-2.5 mg) 1

Bridging Therapy Decision

• Routine bridging is NOT recommended for most patients due to increased bleeding risk 1
• Bridging with LMWH may be considered only for high thrombotic risk patients (mechanical heart valves, recent stroke/TIA, CHADS₂ score ≥5) undergoing high bleeding risk surgery 1
• When bridging is used, start LMWH 36 hours after last warfarin dose (approximately 3 days before surgery) 1
• Give half-dose LMWH on the day before surgery (last dose at least 24 hours pre-procedure) 1

Postoperative Resumption

• Resume warfarin on evening of surgery or next morning for most procedures 1
• For low bleeding risk procedures, restart LMWH at full dose on postoperative day 1 and continue until INR >1.9 1
• For high bleeding risk procedures, hold LMWH until postoperative day 2-3, then restart at full dose 1

Management of Direct Oral Anticoagulants (DOACs)

Apixaban, Rivaroxaban, Edoxaban

For patients with normal/mild renal impairment (CrCl ≥50 mL/min):

• Low-to-moderate bleeding risk surgery: Hold for 1 full day before procedure (last dose 24 hours pre-op) 1
• High bleeding risk surgery: Hold for 2 full days before procedure (last dose 48 hours pre-op) 1

For patients with moderate renal impairment (CrCl 30-49 mL/min):

• Low-to-moderate bleeding risk: Hold for 1 full day 1
• High bleeding risk: Hold for 2 full days 1

For patients with severe renal impairment (CrCl 15-29 mL/min):

• Low-to-moderate bleeding risk: Hold for 36 hours 1
• High bleeding risk: Hold for 48 hours 1

Dabigatran

For patients with normal/mild renal impairment (CrCl ≥50 mL/min):

• Low bleeding risk surgery: Hold for 1-2 days before procedure (skip 2 doses) 1, 6
• High bleeding risk surgery: Hold for 3 days before procedure (skip 4 doses) 1, 6

For patients with moderate renal impairment (CrCl 30-50 mL/min):

• Low bleeding risk: Hold for 3 days (skip 4 doses) 1, 6
• High bleeding risk: Hold for 4-5 days (skip 6-8 doses) 1, 6

Key Principles for All DOACs

• No DOAC is taken on the day of surgery 1
• Bridging therapy is NOT recommended for DOAC-treated patients 1
• Resume DOACs at least 24 hours after low-risk procedures once hemostasis is achieved 1, 6
• Resume DOACs 48-72 hours after high bleeding risk procedures 1, 6

Common Pitfalls to Avoid

• Do not routinely measure anti-factor Xa levels for LMWH bridging; reserve for select high-risk situations only 1
• Do not use full-dose LMWH too close to surgery; this significantly increases major bleeding risk (up to 20%) 1
• Do not assume all patients need bridging; the BRIDGE trial demonstrated that most atrial fibrillation patients do NOT require bridging 1
• Do not forget to adjust DOAC interruption timing for renal function, particularly with dabigatran where 75-80% is renally cleared 1
• Avoid concomitant use of drugs that inhibit CYP3A4 or P-glycoprotein (dronedarone, amiodarone, verapamil), which may require extending DOAC interruption by an additional 24 hours 1