Drug Eluting Stent Questions
(for patients)
- Can my stent be removed so I no longer have a risk of it clotting and causing a heart attack?
NO. The stent must remain in place. The lining of the main artery in the heart grows into the stent, so that removing it would damage the artery and probably cause a heart attack. The drug-eluting stent is designed to limit the growth of the artery lining enough for it not to block the artery. The stent is supposed to allow for enough growth so that the stent itself is covered with the patient’s cells. At the same time it is supposed to prevent excessive cell growth into the artery channel, which would narrow it for the passage of blood. For some sensitive people the stent limits this growth so well that portions of the stent are not covered by cells and come in contact with the blood. An uncovered part of a stent can be a site for clotting. For this reason, patients with drug-eluting stents should continue to take their anticlotting medicine for a long time.
Schwartz RS, Chronos NA, Virmani R. Preclinical Restenosis Models and Drug-Eluting Stents. J Am Coll Cardiol 2004;44:1373-1385. - What are my chances of clotting my drug-eluting stent and having a heart attack if I do or do not take Plavix (clopidogrel) and aspirin?
One study from Duke University evaluated the records of patients who received stents at Duke. People who did not have trouble for the first 6 months had only a 1 in 40 chance of clotting over the next year if they continued their anticlotting medicines, but a 1 in 20 chance of clotting if they stopped their anticlotting medicines 6 months after their stents were inserted. (A)
A different study from Denver evaluated patients beginning one month after stent placement until the end of the first year. They found that 99 patients out of 100 who continued medication were alive at that time. The patients who stopped the anticlotting medicines after only a month and may have discontinued their other medicines as well were older and sicker than the ones who continued the medicines. They had a 1 in 13 chance of dying by the end of the first year. (B)
Another study found that 7 of 121 people (6%) with drug-eluting stents who stopped their medicine developed clots in their stents, while only 4 of many (1790) patients who continued their anticlotting medicine had their stents clot during the period up to 1 ½ years after the stent was inserted. (C)
In a European study, late stent clotting (after 30 days) occurred in 6 per thousand patients per year during the three years after the stent was inserted. (D)One can conclude that it is much better to keep taking the medicine to prevent the stent from clotting than to stop taking the medicine too soon.
A. Eisenstein EL, Anstrom KJ, Kong DF, Shaw LK, Tuttle RH, et. al. Clopidogrel use and long-term clinical outcomes after drug-eluting stent implantation. JAMA 2007;297:159-168
B. Spertus JA, Kettelkamp R, Vance C, Decker C, Joens PG, et.al. Prevalence, Predictors, and Putcomes of Premature Discontinuation of Thienopyridine Therapy After Drug-Eluting Stent Placement. Results from the PREMIER registry. Circulation 2006;113:2803-2809.
C. Park DW, Park SW, Park KH, Lee BK, Kim YH, et. al. Frequency of and Risk Factors for Stent Thrombosis After Drug-Eluting Stent Implantation During Long-Term Follow-Up. Am J Cardiol 2006;98:352-356.
D. Daemen J, Wenaweser P, Tsuchida K, Abrecht L, Vaina S, et. al. Early and late coronary stent thrombosis of sirolimus-eluting and pactitaxel-eluting stents in routine clinical practice: data from large two-institutional cohort study. Lancet 2007;369:667-678. - What is my chance of staying alive with my drug-eluting stent in place?
93% after 4 year follow up (A)
94% after 4 year follow up (B)
94% after 3 years (C)
90% after 5 years (D)
A. Spaulding C, Daemen J, Boersma E, Cutlip DE, Serruys PW. A pooled analysis of data comparing Sirolimus-Eluting Stent with Bare-Metal Stents. N Engl J Med 2007;356:989-997.
B. Stone GW, Moses JW, Ellis SG, Schofer J, Dawkins KD, et.al. Safety and Efficacy of Sirolimus and Paclitaxel-Eluting Coronary Stents. N Engl J Med 2007;356:998-1008..
C. Lagerqvist B, James SK, Stenestrand U, Lindback J, Nilsson T, et. al. Long-term outcomes with drug-eluting stents versus bare-metal stents in Sweden. N Engl J Med 2007;356:1009-1019.
D. Kastrati A, Mehilli J, Pache J, Kaiser C, Valgimigli M, et. al. Analysis of 14 trials comparing sirolimus-eluting stents with bare-metal stents. N Engl J Med 2007;356:1030-1039. - Should I stop my aspirin and Plavix (clopidogrel) before I go to the dentist?
No. A good study has found that people taking aspirin bleed no more after having a tooth pulled than people taking a sugar pill for comparison. In addition, bleeding after a dental procedure can be controlled by direct pressure on the bleeding site until it stops. The risk of harm from a drug-eluting stent clotting if you stop your medicines before one year of therapy is greater than any harm that might occur from some extra dental bleeding. After one year, the risk depends somewhat on factors that may make some people more likely to develop stent clotting. These include having more than one stent, having long stents, having stents in small vessels, having a heart that isn’t pumping blood efficiently, being older, having kidney failure, and having diabetes.
2007 Focused Update of the ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention. Circulation, in press.
Noll JL, Nepanas JJ, Kent ML, Fox PC, Lockhart PB. Relationship between aspirin use and postoperative bleeding from dental extractions in a healthy population. Or Sur Or Med O Pathol Or Radiol End 2006;102:326. - Should I stop my anticlotting medicines if I need surgery?
This is a judgment question and often the answer is to continue the medicines. Most drug-eluting stent clotting occurs in the weeks and months after the stent is inserted, so it is essential to continue the medicines during this period. A year after stent insertion, the risk of clotting is less, but for some people the risk persists for 2 years or more. We have no way at this time to tell those at risk for clotting from those not at risk.
The best information comes from studies of patients who were given aspirin and Plavix (clopidogrel) and then had coronary artery surgery. In general, they had more blood loss and a longer hospital stay than patients having coronary surgery who had not taken these medicines. But there was no increase in the frequency of the other complications of coronary surgery, such as wound infection or having a stroke or heart attack after the operation.
In addition, much surgery today has far less risk of bleeding than in the past. For example, cataract surgery is done through the cornea in the front of the eye. The cornea has no blood vessels so it does not bleed when cut. Another example is the “minimally invasive” surgery made possible by modern fiber optics and new types of instruments. Bleeding is often stopped with lasers that seal the ends of tiny vessels, so far less bleeding occurs with these techniques. The risk of a serious complication from excessive bleeding from many modern surgical techniques is less than the risk of a serious and potentially fatal heart attack from stent clotting if the anticlotting medicine is stopped. For other types of surgery, the decision is less clear. Elective surgery should be postponed until one year after drug-eluting stent insertion, if possible.
Whether one or both anticlotting medicines should be discontinued for surgery and for how long is a question of judgment for the surgeon and the cardiologist to decide between them.
Hongo RH, Ley J, Dick SE, Yee RR. The effect of Clopidogrel in combination with aspirin when given coronary artery bypass grafting. J Am Coll Cardiol 2002;40:231-237.
Cannon CP, Mehta SR, Aranki SF. Balancing the benefit and risk of oral antiplatelet agents in coronary artery bypass surgery. Ann Thorac Surg 2005;80:768-779. - If bleeding occurs, how soon do the effects of anticlotting drugs wear off? What can be done to control the bleeding?
Both aspirin and Plavix (clopidogrel) interfere with the action of existing platelets—the blood cells responsible for controlling bleeding. A study of patients having coronary artery surgery analyzed the frequency of major bleeding in patients in terms of how long before surgery they stopped their anti-platelet therapy (anticlotting drugs). The investigations found major bleeding in 44 patients per 1000 who stopped the medicine 5 days or more before surgery. The risk increased to 93 per 1000 in those who stopped 3 days before surgery and to 111 per 1000 in those who stopped the day before surgery. If bleeding needs to be stopped immediately, platelet transfusions are recommended.
Eikelboom JW, Hirsh J. Bleeding and management of bleeding. Eur Heart J Suppl 2006; 8: G38-G45.
Jakubowski JA, Matsushima N, Asai F, Naganuma H, Brandt JT, et. al. A multiple dose study of prasurgel (CS-747), a novel thienopyridine P2Y 12 inhibitor, compared with clopidogrel in healthy humans. Br J Clin Pharmacol 2006;63:421-430. - What is my risk of bleeding while I am on aspirin with Plavix (clopidogrel)?
In one study of 3759 patients taking these drugs together for 18 months, life threatening bleeding occurred in 3 patients out of 100. A comparison group took aspirin alone and they had a risk of life threatening bleeding in 1 patient per 100. In another study, during an average period of 28 months following stent insertion, patients on aspirin with clopidogrel had a 1.7% chance of severe bleeding and a 2.1% chance of moderate bleeding. In comparison, people receiving low dose aspirin alone had risks of 1.3% for severe bleeding and 1.3% for moderate bleeding.
Diener HC, Bogousslavsky J, Brass LM, Cimminiello C, Csiba L, et.al. Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemicstroke ot transient ischaemic attack in high-risk patients (MATCH): randomized, double-blind, placebo-controlled trial. Lancet 2004;364:331-337.
Bhatt DL, Fox KAA, Hacke W, Berger PB, Black HR, et. al. Clopidogrel and Aspirin versus Aspirin Alone for the Prevention of Atherothrombotic Events. N Engl J Med 2006;354:1706-1717. - Suppose my stent does clot; what will happen?
Clotting of a stent is a serious problem. In one study, of 47 episodes of stent clotting, there were 18 non-fatal heart attacks and 28 deaths (a death rate of 60%). Another study reported 15 stent clots with 5 deaths (a 33% death rate).
Eisenstein EL, Anstrom KJ, Kong DF, Shaw LK, Tuttle RH, et. al. Clopidogrel use and long-term clinical outcomes after drug-eluting stent implantation. JAMA 2007;297:159-168.
Park D-W, et al. Frequency of and risk factors for stent thrombosis after drug-eluting stent implantation during long-term follow-up. Am J Cardiol 2005; 98: 352-6.