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Managing Anticoagulation Therapy For Surgery and Procedures (NEJM)
One in 50 people in the U.S. are taking long-term anticoagulation therapy for a condition like atrial fibrillation, a mechanical heart valve, or a clotting disorder resulting in DVT / PE. Millions more with coronary artery disease or strokes are taking antiplatelets drug like Plavix, and often aspirin as well. About 1 in 10 people on anticoagulation therapy undergo surgery or an invasive procedure each year, and the management of their anticoagulation medicines can be challenging: the physician is expected to simultaneously prevent serious bleeding during the surgery, and also clotting resulting in pulmonary embolism, heart attack, or embolic stroke. Tricky!
Procedures Not Necessarily Requiring Interruption of Anticoagulation
According to the authors, these procedures have a risk of serious bleeding < 1.5%, and if this is acceptable, anticoagulation may be continued with a target INR of 2.5. Authors also advise that full-dose antiplatelet therapy (e.g., Plavix) may be continued through these procedures. (The risk of warfarin and antiplatelet therapy in combination was not addressed.)
|Arthrocentesis||Bronchoscopy (Dx)||EGD (mucosal bx OK)||Cardiac cath (Dx)*|
|Thoracentesis||Some FNAs*||Colonoscopy (Dx)||Endotracheal Intubation|
|Paracentesis||IVC filter plcmt||Minor skin surgery||Colposcopy (Dx)|
|Central Lines||Vas-Cath for HD||Tooth extraction||Dilation & curettage|
|PICCs||Small abd/pelvis drains||Root canals||PEG,nephrostomy tube exchange|
* "controversial," say authors
Procedures With High Bleeding Risk: Interrupting Anticoagulation Advised
More-invasive surgeries and procedures are expected to cause serious bleeding in >1.5% of people taking anticoagulation therapy. Anticoagulation should be interrupted for these procedures, as well as those in body areas vulnerable to injury (e.g., spinal cord). Patients at high risk for clotting with anticoagulation interruptions should be considered for "bridging therapy" with heparin. This is not a complete list.
|Lumbar puncture||Chest tube plcmt||Arterial puncture||Spinal/epidural anesthesia|
|Transbronchial bx||Stricture dilations||Organ biopsies||Tunneled catheter plcmt|
|Cardiac ablations||Liver/GB drains||Nephrostomy||ERCP w sphincterotomy|
|PEG tube plcmt||Cardiac cath PCI||Pacemaker plcmt||>1cm polypectomy|
|Major surgery||Wide skin excision||Eye surgery (not cataracts)||Vascular interventions|
Decision-Making for Anticoagulation for Procedures & Surgery
Each patient's situation should be considered individually and he/she included in the decision making and risk discussion. Generally speaking, the authors advised these principles.
For most patients undergoing low-bleeding-risk procedures:
- Interruption of warfarin is not necessary;
- The INR should be adjusted to ~2.5 if possible.
- Antiplatelet therapy like Plavix may be continued.
- (Warfarin and Plavix's risks if taken together were not addressed).
For most patients undergoing high-bleeding-risk procedures:
- For those who are at low individual risk for clotting, anticoagulation can be interrupted without bridging therapy (heparin).
- Most patients at high individual risk of blood clots should receive bridging anticoagulation therapy.
Bridging therapy is strongly recommended for people with:
- DVT or PE within the past 3 months or severe thrombophilia;
- Mechanical mitral valves,
- "Old" design mechanical aortic valves (caged-ball or tilting-disk design, i.e., non-bileaflet),
- Any mechanical valve with a history of stroke or transient ischemic attack,
- Non-valvular atrial fibrillation with a CHADS2 score 4 or greater, history of stroke or TIA, or cardiac thrombus.
In people with recent DVT or PE (< 3 months since diagnosis), authors advise delaying elective surgery for 3 months while anticoagulating. If surgery must be performed, consider bridging therapy, and in those who've received less than one month of anticoagulation, consider the placement of an IVC filter as well.
For patients taking dual antiplatelet therapy after placement of coronary artery stents (aspirin plus Plavix or a similar drug):
These patients are at increased risk for sudden coronary artery thrombosis in the stent with "early" discontinuation of antiplatelet therapy. This risk is particularly elevated in the first 6-12 months after stent placement, especially for drug-eluting stents. This risk needs to be balanced against the necessity of the invasive procedure and its risk of causing serious bleeding. Authors advise:
- Postpone elective procedures / surgeries for at least 6 weeks after a bare-metal stent is placed, and for 6 months if a drug-eluting stent was placed.
- If the procedure/surgery is high-bleeding-risk (see above), delay it as long as feasible -- optimally, more than a year after stent placement of any kind.
- Here's the tough part: If a high-bleeding-risk procedure must be performed before completion of 6 weeks antiplatelet therapy (for bare-metal stents) or 6 months (for drug-eluting stents), it's recommended to continue both Plavix and aspirin throughout the invasive procedure whenever possible, and to never discontinue aspirin. There's no known effective reversal agent to prevent the massive bleeding that often results, but platelet transfusion may be tried.
- After 6 weeks / 6 months of dual antiplatelet therapy (depending on stent type) have elapsed post-PCI, elective procedures can be performed after interrupting Plavix for 5 days pre-procedure (or longer for Effient/Ticlid), but continuing aspirin.
- For low-bleeding-risk procedures (see above) in patients taking dual antiplatelet therapy, authors advise continuing both aspirin and the Plavix-type drug.
There is a lot more to this complex subject, and the consequences of these medical decisions can be lifesaving (or catastrophic); please read the literature or consult other specialist physicians before making decisions on your own patients, if you are unsure of what to do. This summary can only provide assistance, not definite answers.
With gratitude to:
Todd H. Baron, Patrick S. Kamath, and Robert D. McBane. Management of Antithrombotic Therapy in Patients Undergoing Invasive Procedures. N Engl J Med 2013; 368:2113-2124.
James D. Douketis et al. Bridging Anticoagulation: Is it Needed When Warfarin Is Interrupted Around the Time of a Surgery or Procedure? Circulation 2012; 125: e496-e498.