• Blood clot formation (thrombosis)

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    After either a bare metal or drug-eluting stent is implanted, there is a small chance that a blood clot may form on its surface.  The chance of forming blood clots is low (it occurs in less than one in 200 patients). However, if blood clots form, the complications can be serious.  They can result in recurrent chest pain or heart attack.  

    To prevent clots from forming, medications that thin the blood and prevent it from clumping to form clots are prescribed to all patients – no matter which type of stent is implanted. These “anti-platelet” medications currently include aspirin and clopidogrel (Plavix®).

    If you receive a bare-metal stent, your doctor will prescribe aspirin and Plavix for at least one month after your procedure.  

    If you receive a drug-coated, or drug-eluting, stent, current recommendations are to continue daily aspirin and Plavix for at least a year after your procedure. 

    Late Stent Thrombosis, or the risk of blood clots a year or more after receiving a stent 

    Reports have raised the concern that the risk of a blood clot forming a year or more after a stent is implanted, particularly the drug-coated stents, may be greater than previously believed. 

    A study published in 2006 reported that about two to three out of 1,000 patients who received a drug-eluting stent developed a blood clot a year or more after receiving the stent. (This is referred to as “late stent thrombosis”). While the study confirmed that the risk of a blood clot is rare, it pointed to a higher-than-expected risk.   

    Years of clinical evidence have proven that, compared with bare metal stents, drug-eluting stents reduce the likelihood that the vessel will re-narrow due to scar tissue build-up – and reduce the chance a repeat procedure will be needed to re-open the artery.  That’s why many physicians continue to prescribe drug-eluting stents.  

    However, to guard against blood clots, they strongly recommend that, if you receive one or more drug-coated stents, you should take blood-thinning drugs, including aspirin and Plavix, for a year or longer.  

    If for any reason you may not be able to take blood-thinning medications for the entire time period your doctor prescribes, you should let him or her know before a stent is implanted.  And you should not, under any circumstances, stop taking the anti-platelet medicines without first checking with your cardiologist.

    Reasons why you may not be able to take the drugs include: 

    • Planned surgery or dental work;
    • Difficulty paying for the anti-clotting drugs;
    • You have a history of not taking your prescriptions; or
    • Unpleasant side effects from the drugs.

    Click here to view a video about the procedure after receiving stent.