Requiring patients with drug-eluting stents to wait a year before they can undergo elective surgery "is a common problem" for surgeons. But a large-scale study indicates the risk of adverse events such as serious blood clots may be overblown.
To avoid major adverse events like thrombosis, surgeons require patients implanted with drug-eluting stents (DES) to wait at least one year before they may safely undergo elective surgeries.
But a large-scale study indicates the risk of adverse events such as serious blood clots may be overblown and half of that wait may be unnecessary. The report suggests that patients need only wait six months, with no more risk than patients implanted with bare metal stents (BMS).
"Our study, in combination with several other large population-based studies published in the last several years, will probably prompt cardiology societies to revisit their guidelines and clarify when it may be safe to operate on a patient with DES, and under what conditions," says Mary Hawn, MD, of the Department of Surgery at the University of Alabama at Birmingham, the study's corresponding author.
"What we found is that there's really no difference in outcomes based on stent type."
Hawn and fellow researchers can't say definitively how many patients might benefit from earlier surgery, but she notes that requiring patients to wait before they can undergo needed but non-urgent surgeries "is a common problem for us [surgeons]. I do think that there are many patients I see in my own practice who are upset by the delay, because they have symptoms they want to have treated."
Additionally, surgery to relieve pain may prompt patients to move more, which may reduce their heart disease risks.
Hawn's report, based on a sample of 41,989 stent procedures between 2000 and 2010, and which tracked surgery related events for two years, was published online Monday in the Journal of the American Medical Association.
The study is important because more than 600,000 procedures a year involve the placement of one or more stents, and often patients require subsequent surgery for unrelated medical conditions. About 60% to 70% of those stents are DES.
Hawn explains that after DES were introduced in 2004, they rapidly oversold bare metal stents until researchers noticed a proliferation of stent thrombosis in DES patients. That prompted the American Heart Association and the American College of Cardiology in 2007 to jointly issue guidelines calling for non-cardiac surgery to be delayed for patients for at least one year subsequent to DES implantation. The delay was intended to allow for one year of dual antiplatelet therapy (an aspirin and a platelet receptor inhibitor) to prevent adverse events such as clots.
Patients with bare metal stents are advised to wait six weeks under current guidelines, but Hawn's research suggests that surgeons might wait six months before operating on the BMS patient as well, especially if an acute myocardial infarction is what prompted the stent in the first place.
"It seems that if the patient had an acute myocardial infarction, their risk seems elevated for quite some time, close to the six-month mark. So if a patient had a BMS following an AMI we might want to pause and really question whether we should wait longer than six weeks for those patients."
Further research by her team will explore in more detail whether it's the stent itself that puts the patient at higher risk of a subsequent surgical adverse event, or the underlying cardiac disease.
Whatever the guideline is, patients who have had stents, especially DES, should undergo any surgery at a medical center with primary percutaneous coronary intervention capability in case a stent thrombosis occurs during the surgery, wrote Emmanouil Brilakis, MD, and Subhash Banerjee, MD, of the VA North Texas Health Care System and the University of Texas Southwestern Medical Center at Dallas In an accompanying editorial.
Patients with BMS can usually safely undergo surgery "within six weeks after coronary stent implantation with very low risk of stent thrombosis, they added. For patients with DES, surgery performed at least six months after DES implantation appears to carry low risk for stent thrombosis, especially with contemporary, second-generation DES, which have more biocompatible, durable polymer coatings."