Preoperative Management of Coronary Stents

Dr. Ihab Suliman

Ingrowth of tissue may cause bare-metal stents to become obstructed, resulting in the need for a second procedure. Drug-eluting stents inhibit this process, but uncovered struts may be prone to thrombosis after discontinuation of antiplatelet therapy. 

Perioperative coronary stent thrombosis is a catastrophic complicationthat can occur in patients receiving both bare-metal and drug-elutingstents.

Noncardiac surgery appears to increase the risk that recently-placed stents thrombose, especially when surgery is performed early after stenting, and particularly if dual antiplatelet therapy is discontinued.

In patients with a bare metal coronary stent who require surgery within 6 weeks of stent placement, we recommend continuing aspirin and clopidogrel in the perioperative period (Grade 1C);

In patients with a drug-eluting coronary stent who require surgery within 12 months of stent placement, we recommend continuing aspirin and clopidogrel in the perioperative period (Grade 1C).

ACCP 8th Version

The optimal duration of clopidogrel required to prevent late DES thrombosis is unknown.

an observational study showed reduced risk of death or MI when clopidogrel was continued up to 2 years after DES implantation

  • Continue dual antiplatelet therapy during and after surgery 

• Discontinue clopidogrel but "bridge" the patient to surgery using a short-acting antiplatelet agent with a glycoprotein IIb/IIIa inhibitor or an antithrombin, and restart clopidogrel as soon as possible after surgery 

• Discontinue clopidogrel before surgery and restart it as soon as possible after surgery 

Antiplatelet treatment strategies to minimize perioperative stent thrombosis include:

some clinicians "bridge" the patient to surgery using a short-acting antiplatelet agent or an anticoagulant. Because stent thrombosis is primarily a platelet-mediated phenomenon, platelet inhibitors might be a more logical choice if such a strategy is pursued. Furthermore, the cessation of heparin in a patient not on aspirin or other antiplatelet agents has been shown to cause platelet activation and a rebound phenomenon which may actually increase the likelihood of perioperative stent thrombosis compared to if no heparin bridging had been performed.  

Bridge

However, it must be emphasized that admitting a patient to a hospital before surgery to bridge them to surgery does not offer complete protection because the greatest risk of stent thrombosis is actually during or after surgery.

We systematically searched Medline for reported cases of late stent thrombosis and very late stent thrombosis published between January 2001 and July 2008. We restricted our search to Academic Research Consortium–defined definite cases. We identified 161 cases of late stent thrombosis or very late stent thrombosis from 84 articles (

Circulation March 2009

79 from case reports, 61 from registries, and 21 from randomized clinical trials). Patients had a mean age of 58.4±13.4 years, and 88% were male. A total of 19 cases occurred in patients who were receiving dual antiplatelet therapy at the time of the event. If patients stopped both antiplatelet agents simultaneously, the median time to event was 7 days. If patients had previouslystopped a thienopyridine with no ill effect and subsequently stopped acetylsalicylic acid, the median time to event was also 7 days from the time of acetylsalicylic acid cessation.

If the thienopyridine was stopped but acetylsalicylic acid was maintained, the median time to event was 122 days. Among the 48 patients who stopped both agents, 36 cases (75%) occurred within 10 days. Among the 94 patients who discontinued a thienopyridine but continued acetylsalicylic acid, only 6 cases (6%) occurred within 10 days.

 If acetylsalicylic acid therapy is maintained, short-term discontinuation of a thienopyridine may be relatively safe in patients with drug-eluting stents.

The real-world use of the CYPHER stent is safer than was shown in clinical trials.

According to the MATRIX Registry, which is sponsored by Cordis, CYPHER's manufacturer, rates of stent thrombosis at one year were lower than clinical trials reported.

Most patients in the MATRIX Registry, up to 80%, have chronic conditions such as diabetes that would have disqualified them from clinical trials, and therefore received stents off-label. MATRIX investigators also found that many patients had trouble maintaining the clopidogrel regimen and that one-third were no longer taking the drug as recommended at one year.

Found that off-label use of sirolimus-eluting stents led to low two-year rates of complications and thrombosis.

Of 1,521 patients, 34% had diabetes, 45% had prior percutaneous coronary intervention, 21% had prior coronary artery bypass grafting, 33% had prior MI and 46% had acute cardiac syndrome at baseline.

The MATRIX Registry

Two years after stenting, rates of cardiac death, non-cardiac death, MI, target lesion revascularization and target vessel revascularization were 1.1%, 1.7%, 4%, 9% and 12%, respectively.

The Matrix Registry