Should acitrom (acenocoumarol) be discontinued before the scheduled mitral valve stenosis and tricuspid annuloplasty given the patient's INR of 1.15?

Acitrom Management for Cardiac Surgery with INR 1.15

With an INR of 1.15, acitrom (acenocoumarol) should be discontinued and bridging anticoagulation with therapeutic-dose LMWH or UFH should be initiated immediately, as this patient with mitral valve stenosis requiring valve surgery represents a high thromboembolic risk scenario. 1

Risk Stratification

This patient falls into the high thromboembolic risk category based on:

• Mitral valve stenosis requiring surgical intervention 1
• Planned mitral valve surgery (stenosis repair) and tricuspid annuloplasty 1
• The current subtherapeutic INR of 1.15 indicates inadequate anticoagulation 1

Preoperative Anticoagulation Management

Acenocoumarol Discontinuation Timeline

Acenocoumarol should be stopped 2-3 days before surgery (shorter than warfarin's 5-day window due to its shorter half-life) 1. The current INR of 1.15 suggests the patient may already be partially interrupted or subtherapeutic.

Bridging Therapy Protocol

Initiate therapeutic-dose LMWH or UFH bridging immediately given the high thromboembolic risk: 1

• LMWH dosing: Enoxaparin 1 mg/kg twice daily or dalteparin 100 IU/kg twice daily 1
• UFH alternative: For mechanical valves or very high-risk patients, IV UFH may be preferred, discontinued 4-6 hours before surgery 1
• Last LMWH dose: Administer at least 12 hours before the procedure 1

Day of Surgery INR Check

On the day of surgery, verify INR is ≤1.5 before proceeding 1. If INR >1.5, consider postponing the procedure 1. For urgent surgery with elevated INR, use 4-factor prothrombin complex concentrate rather than high-dose vitamin K to avoid creating a hypercoagulable state 1.

Postoperative Anticoagulation Management

Resumption of Acenocoumarol

Resume acenocoumarol within 24 hours postoperatively (typically the evening of surgery or next morning) at the usual maintenance dose, provided adequate hemostasis is achieved 1. Some protocols recommend a 50% boost dose for two consecutive days 1.

Postoperative Bridging

Continue therapeutic LMWH or UFH bridging until INR returns to therapeutic range (typically 2.5-3.5 for mitral valve surgery) 1. For high-bleeding-risk cardiac surgery:

• Consider prophylactic-dose LMWH for first 24-48 hours post-procedure 1
• Transition to therapeutic-dose LMWH 2-3 days postoperatively based on hemostatic stability 1
• Resume bridging at least 12 hours after the procedure 1

Target INR Range

For mitral valve surgery, target INR should be 2.5-3.5 1. This higher range compared to aortic position reflects the greater thromboembolic risk associated with mitral valve procedures 1.

Critical Pitfalls to Avoid

• Never use high-dose vitamin K for routine reversal in patients with valve disease, as this creates a hypercoagulable state and increases valve thrombosis risk 1
• Do not delay bridging therapy in high-risk patients like those with mitral stenosis—the current INR of 1.15 already indicates subtherapeutic anticoagulation requiring immediate intervention 1
• Acenocoumarol has a shorter half-life than warfarin—interruption timing differs (2-3 days vs 5 days), and INR fluctuations can be more pronounced with uneven dosing 1, 2
• Avoid resuming full-dose LMWH too early postoperatively in cardiac surgery due to major bleeding risk (up to 20% if given without regard to surgical bleeding risk) 1