Delaying noncardiac surgery after stent implantation may reduce cardiac events

Risks associated with noncardiac surgery are highest in the first 6 months after coronary stent implantation, and a new study suggests that delaying noncardiac surgery for at least 6 months may yield improved outcomes in patients after stenting.

Researchers performed a retrospective cohort study to analyze the incremental risk of noncardiac surgery on coronary revascularization and MI after stent implantation. Patients who received coronary stents from 2000 to 2010 were accrued from US Veterans Affairs medical centers. The cohort included 20,590 patients (surgical cohort) who underwent noncardiac surgery within 24 months of stent implantation and 41,180 patients (nonsurgical cohort) who did not undergo noncardiac surgery after stent implantation during that time period.

The rate of the composite cardiac endpoint of revascularization and/or MI within 30 days after noncardiac surgery was 3.1% for the surgical cohort vs. 1.9% for the nonsurgical cohort (P<.001). Rates of MI (2.5% vs. 1.1%) and all-cause mortality (1.4% vs. 0.4%) also were higher in the surgical cohort (P<.001 for both). The researchers reported no difference between the cohorts in rates of revascularization alone (1.1% vs. 1%; P=.37). During the 30-day period after surgery, the risk difference for MI in the surgical cohort was 1.4% and the risk difference for all-cause mortality was 1% compared with the nonsurgical cohort, according to the results.

After adjustment for surgical characteristics, the incremental risk for noncardiac surgery was 3.5% in the period after stent implantation to 6 months and decreased to 1% at 6 months; thereafter, risk remained stable through 24 months, according to the researchers.

Elective inpatient procedures, high-risk surgery and drug-eluting stent implantation were identified as factors associated with significant reduction in risk following noncardiac surgery more than 6 months after stent implantation (P=.01 for all). “When appropriate, these circumstances may benefit most from delay until at least 6 months following stent [implantation], whereas minor outpatient procedures were associated with insignificant incremental risk,” the researchers wrote.

“Furthermore, although the incremental risk decreased for both bare-metal stents and drug-eluting stents, the change was significant only for drug-eluting stents when surgery was more than 6 months after stent placement. Underlying patient conditions inherent to decision making for bare-metal stent placement, not necessarily stent characteristics, likely explain this,” they concluded. “These results further refine the incremental risk of noncardiac surgery in patients with coronary stents and how the risk is modulated over time.”

Source: www.healio.com