Timing of Noncardiac Surgery Following Percutaneous Coronary Intervention

Although current US and European guidelines recommend delaying surgery in patients for 6 to 12 months after drug-eluting stent percutaneous coronary intervention (DES-PCI), a new study published in the Journal of the American College of Cardiology suggests surgery might be performed earlier without increased risk.¹

Researchers in Aarhus, Denmark, collected data on 22,590 patients who underwent DES-PCI between 2005 and 2012. A total of 4303 patients were compared with a control group (n=20,232) without previous ischemic heart disease who underwent similar surgical procedures. Both first-generation DES and second-generation DES were used. Myocardial infarction, cardiac death, and all-cause mortality were assessed 30 days after surgery.

As the authors noted, patients implanted with earlier generations of DES are given dual antiplatelet therapy for 6 to 12 months to reduce stent thrombosis risk. A systematic review² found that approximately 4% to 15% of patients who undergo PCI with DES require surgery within 12 months after stent implantation, and the risk for adverse cardiac events may be increased if performed before 6 months have passed.

More than 5000 patients (23%) of the 22,590 treated with DES-PCI underwent surgery within 12 months, excluding 430 who received oral anticoagulation therapy. These patients were matched with patients without ischemic heart disease.

Patients treated with DES-PCI who underwent surgery had an increased risk for myocardial infarction (1.6% vs 0.2%; odds ratio [OR], 4.82; 95% confidence interval [CI], 3.25-7.16) and cardiac death (1.0% vs 0.2%; OR, 5.87; 95% CI, 3.60-9.58). However, they were not at an increased risk for all-cause mortality (3.1% vs 2.7%; OR, 1.12; 95% CI, 0.91-1.38).

Between the DES-PCI patients and those without ischemic heart disease, there were several differences in drug therapy, including statins, beta-blockers, nitrates, proton pump inhibitors, P2Y₁₂ inhibitors, and aspirin. In addition, 76.9% of patients treated with DES-PCI had at least 1 comorbidity (as assessed by the Charlson Comorbidity Index) compared with only 27.6% of patients without ischemic heart disease.

There were more surgeries performed within the first 3 months after PCI (34%) than at the >3- to 6-month (25%), the >6- to 9-month (21%), or the >9- to 12-month (20%) marks. In particular, surgery within the first month after DES-PCI was associated with a significantly increased risk for all events, but after the first month, no significant differences were seen compared with surgery at the >9- to 12-month mark.

Surgery timing (≤1 month vs >1-12 months), emergency surgery (acute vs elective), and acute coronary syndrome as an indication for DES-PCI, peripheral artery disease, and renal disease were factors associated with the highest risk for events.

“The increased risk was only present within the first month after DES-PCI, suggesting that surgery might be undertaken earlier than currently recommended,” the authors concluded.

More studies are still needed to determine the best course of antithrombotic therapy in patients who undergo noncardiac surgery within the first year after DES implantation.

Study Limitations

• The study was retrospective in nature.
• Information on surgery timing may have been “affected by confounding by indication because the use of [dual antiplatelet therapy] might have led to delay or even cancellation” of surgery.
• No data available on antithrombotic therapy management.
• High rate of adverse events within the first month may suggest that the concomitant therapy with antiplatelet therapy “unmasked malignant conditions or that the PCI-related hospitalization revealed conditions that led to accelerated surgical procedures.”
• Higher rate of cardiac death classifications among patients with known ischemic heart disease, which may have been caused by too many deaths classified as cardiac-related among DES-PCI patients, too few classified among those without ischemic heart disease, or a combination of factors.

Dr Egholm has received speaker honorarium from Bayer. Dr Kristensen has received a senior research grant from the Novo-Nordisk Foundation. Dr Thim has received an educational grant from St. Jude Medical and a travel grant from Biosensors. Dr Bøtker is a member of the AstraZeneca and Novo Nordisk advisory boards.

References

1. Egholm G, Kristensen SD, Thim T, et al. Risk associated with surgery within 12 months after coronary drug-eluting stent implantation. J Am Coll Cardiol. 2016;68:2622-2632. doi: 10.1016/j.jacc.2016.09.967.
2. Hollis RH, Graham LA, Richman JS, et al. Adverse cardiac events in patients with coronary stents undergoing noncardiac surgery: a systematic review. Am J Surg. 2012;204:494-501. doi: 10.1016/j.amjsurg.2012.04.008