In noncardiac surgery, prior coronary stent implantation is an independent risk factor for major adverse cardiac and cerebrovascular events (MACCE) and bleeding when surgery takes place less than 1 year from stenting, according to a new study published in the Journal of the American College of Cardiology.

As more coronary stent implantations occur, clinicians are more likely to encounter patients in noncardiac surgery cases who have had these procedures in the past. Current international guidelines recommend postponing nonurgent noncardiac surgery for at least 1 month after bare metal stent (BMS) implantation and 6 to 12 months after drug eluting stent (DES) implantation.

Researchers evaluated 24 313 noncardiac surgery cases at the Mayo Clinic in Rochester, Minnesota from 2006 through 2011; 1120 (4.6%) of which involved patients with coronary stents.


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The primary end point for this study was defined as the occurrence of MACCE (eg, death, myocardial infarction, cardiac arrest, and stroke) during surgery and up to 30 days after.

The 30-day MACCE rate was low, occurring in 3.7% of patients with a stent and in 1.5% patients without a stent (P<.001). Significantly higher perioperative death rates were seen in stented patients (2.5% vs 1.0%; P<.001) as well as myocardial infarction (1.3% vs 0.3%; P<.001). However, cardiac arrest and stroke rates were not significantly higher in the stented group (0.6% vs 0.3%; P=.077 and 0.4% vs 0.3%; P=.637, respectively). Bleeding occurred in 20% of patients with stents and 11% in patients without stents (P<.001).

Most noncardiac surgeries were performed within the first 2 years after stenting (median time: 4.5 years). There was a high risk of MACCE when noncardiac surgery was performed early after stent implantation and then a progressive decline of perioperative risk over time (P=.006).

Researchers also calculated MACCE risks in patients depending on stent type. Interestingly, MACCE risks increased in patients after implantation of BMS (adjusted odds ratio [aOR]: 4.21; 95% confidence interval [CI]: 1.49-11.91) but not DES (aOR: 1.03; 95% CI: 0.22-4.78). Bleeding risk only increased in the first year after implantation, regardless of stent type.

“Perioperative outcome after [noncardiac surgery] in patients with stents represents a highly complex interplay between time, patient’s surgical and cardiac risk, clinical decision-making, and the initial need for dual antiplatelet therapy after stenting,” the authors noted. “Therefore, the findings of our study should be seen as complimentary to studies reporting on other important aspects of this process that we were unable to elucidate, such as the role of antiplatelet therapy.”

Researchers concluded that perioperative risk beyond the 6-month mark could be at least partially be attributed to patients with prior BMS implantation, which confirms other recent reports. However, they remarked that this finding “also contradicts the common belief that risk is only elevated in the first month after BMS implantation.”

Reference

Mahmoud KD, Sanon S, Habermann EB, et al. Perioperative cardiovascular risk of prior coronary stent implantation among patients undergoing noncardiac surgery. JACC. 2016;67(9):1038-1049. doi: 10.1016/j.jacc.2015.11.063.