Effect of previous coronary stenting on subsequent coronary artery bypass grafting outcomes

Objectives: The effect of previous coronary stenting on subsequent coronary artery bypass graft is inconclusive. Methods: We used Taiwan's National Health Insurance Database to retrospectively evaluate patients with multivessel coronary artery bypass graft between January 2000 and December 2013. Overall, 32,335 patients who received coronary artery bypass graft were included, of whom 3028 had previous coronary stenting. Propensity-score matching yielded 2977 cases each for evaluation under the previous stenting and no stenting groups. The 30-day mortality and major adverse cardiac events, including all-cause mortality, acute myocardial infarction, and revascularization, were considered primary outcomes. Results: The number of coronary artery bypass grafts decreased per year. However, the percentage of patients who had previous coronary stent implantation before coronary artery bypass graft increased steadily (P for trend <.001), and the average number of stents implanted in a patient also increased per year (P for trend <.001). The previous stent group had a significantly greater 30-day mortality rate than did the no-stent group (7.2% vs 5.0%; odds ratio, 1.47; 95% confidence interval, 1.19-1.82). The previous stent group had a greater rate of revascularization (14.4% and 10.0%; subdistribution hazard ratio, 1.50; 95% confidence interval, 1.30-1.74) in the last follow-up at year 13. Conclusions: Previous coronary stenting before coronary artery bypass graft for multivessel coronary artery disease significantly increased 30-day mortality but did not affect late survival. However, patients who had coronary stenting before coronary artery bypass graft experienced more revascularization events during late follow-up.