Is vein graft use linked to long-term survival after coronary bypass grafting?

No interaction exists between surgeon proclivity for vein graft utilization and long-term survival among Medicare beneficiaries undergoing single arterial graft (SAB) coronary artery bypass grafting (CABG), reports a study, noting that a conservative approach to vein graft utilization is reasonable.

“Although placement of at least one arterial graft during CABG has a proven survival benefit, it is unknown what degree of revascularization with saphenous vein grafting (SVG) is associated with improved survival,” said the researchers.

To address this, the team conducted a retrospective, observational study of SAG-CABG in Medicare beneficiaries from 2001 to 2015. They stratified surgeons by the number of SVG used per SAG-CABG into conservative (≥1 SD below mean), average (within 1 SD of mean), and liberal (≥1 SD above mean).

Kaplan-Meier analysis was used to estimate long-term survival, which was then compared among surgeon groups before and after augmented inverse-probability weighting.

From 2001 to 2015, a total of 1,028,264 Medicare beneficiaries undergoing SAG-CABG (mean age 72.0 years, 68.3 percent male) were identified.

One- and two-vein SAG-CABG utilization rose over time, while three- and ≥four-vein SAG-CABG use declined (p<0.001). Surgeons in the conservative group carried out a mean of 1.7 vein grafts per SAG-CABG, while those in the liberal group conducted a mean of 2.9 vein grafts per SAG-CABG.

On weighted analysis, there was no difference observed in median survival among patients undergoing SAG-CABG by liberal or conservative vein graft users (adjusted median survival difference, 27 days).