As interventional cardiologists we are often asked when patients can stop Plavix (clopidogrel) after their cardiac stent prior to upcoming surgery.   In a perfect world our response would be “never” and we would contentedly admire our stent work from afar.  However clopidogrel does increase bleeding risks during surgery, the world is far from perfect, and choices must be made in the interests of our patients.

Issues of Timing and Stent Choice

The biggest determinants of safety in holding clopidogrel include the time elapsed since the stent was placed and the type of stent used, specifically a bare metal stent versus a drug-eluting stent. 

All stents require time to endothelize the stent struts and lower the risk of acute thrombosis, often a catastrophic event.  Acute stent thrombosis is rare (less than 2 %), but carries a substantially higher death rate compared to patients with initial myocardial infarctions and appears to be strongly correlated with the premature discontinuation of clopidogrel.  The original cardiac stents, or so-called bare metal stents, usually complete neointimal coverage within 3 to 6 months of placement, substantially reducing the risk of acute closure. The current recommendations after bare metal stent placement suggest clopidogrel for a minimum of one month and ideally up to 12 months after stent placement. The more recent drug-eluting eluting stents have a higher rate of early acute stent thrombosis due to delayed neointimal coverage, often not complete even at 21 months.  The minimum duration of clopidogrel treatment recommended post drug-eluting stent is at least 12 months.  In the majority of patients drug-eluting stents are favored due to a demonstrably lower rate of restenosis (up to 40 % with bare metal versus less than 10 % with drug-eluting), lower rates of repeat revascularization and major adverse clinical events.  Although stent thrombosis at one year may be equal in properly anticoagulated patients with bare metal versus drug-eluting stents, many interventionalists are now advocating indefinite use of clopidogrel after placement of drug-eluting stents due to reports of acute thrombosis noted several years post placement.  

Obviously if surgery is anticipated prior to cardiac intervention, then the onus is on the cardiologist to discuss the best approach with the surgeon.  If surgery is needed on a short-term basis such as a malignancy or hip fracture, then plans should be made accordingly for “plane old balloon angioplasty (POBA)” or a bare metal stent.  If surgery can be safely delayed 6 months to a year  (i.e. surveillance colonoscopy, cosmetic surgery, or perhaps epidural injections), or if the coronary anatomy or patient’s risk profile strongly favor use of drug eluting stents, then discussion should be had with both the patient and surgeon regarding the optimal approach.  High-risk characteristics favoring drug-eluting stents include diabetes, a restenosis of a previously placed stent (leading to a stent within a stent), large myocardial territories at risk, relatively young patients and small, diffusely diseased vessels. 

Holding clopidogrel for 5-7 days before the planned surgery is usually sufficient to substantially reduce bleeding risks.  High-risk patients may benefit from “bridging” therapy with heparin and should have surgery at centers equipped to perform emergency rescue angioplasty.    Perioperative chest pain or ST segment elevation is a strong indication of acute stent thrombosis and justifies immediate cardiac catheterization.         Current consensus recommendations for elective surgery following coronary intervention are as follows:

1.     Delay surgery for at least 2 weeks post POBA.  No clopidogrel is required.

2.     Continue Aspirin whenever possible during the surgery.

3.     Surgery with low bleeding risks should continue clopidogrel.

4.     Delay surgery for 4-6 weeks after bare metal stents when holding clopidogrel for patients considered at least moderate bleeding risks.

5.     Delay surgery for at least 6 and preferably 12 months after drug-eluting stents when holding clopidogrel for patients considered at least moderate bleeding risks.

6.     Resume clopidogrel as soon as possible post-operatively with a 300-600 mg bolus (ideally day 1 post-op).

 Currently marketed drug eluting stents in the United States

When Time is of the Essence

We don’t always have the luxury of delaying surgery after a stent procedure. In true emergent surgeries, with a patient fully anticoagulated with clopidogrel, the best approach is to be prepared to liberally treat potential bleeding problems with platelets (unless TTP has developed), fresh frozen plasma, and blood transfusions.  For surgeries with high bleeding potentials, the administration of preoperative platelets should improve hemostasis.  In those instances were a few days of delay before surgery is acceptable, the various forms of the platelet function assay test (PFA) can help gauge the level of platelet inhibition and aid in the timing surgery.

Recently more attention has focused on those patients who may show antiplatelet resistance and require larger doses of clopidogrel to fully inhibit platelet aggregation and the potential decreased effectiveness of clopidogrel when used with proton pump inhibitors.  Several major pharmaceutical companies are also investigating platelet inhibitors with lower bleeding risks compared to clopidogrel.

At the Orlando Heart Center we welcome your calls regarding the use of clopidogrel and surgery.  Together we can enhance the safety and outcomes of our mutual patients.