Multiarterial Grafting and Survival After Coronary Artery Bypass Grafting: An Instrumental Variable Analysis
Main finding · Risk-adjusted median survival, IV modelResult — go to the resultDifference 0.01 yearsAuthors' conclusion
MAG was associated with a modest improvement in long-term survival in a conventional risk-adjusted analysis. However, this association was not robust to a quasi-experimental analysis in which surgeon MAG rate was incorporated as an IV to address unmeasured confounding.
Study context
- Population
- Medicare beneficiaries who underwent coronary artery bypass grafting (CABG), 2001–20194,164 surgeons
- Participants
- 1,291,314 beneficiaries
- Exposure
- Multiarterial grafting (MAG) vs single arterial grafting (SAG) during CABG
- MAGn = 145,554
- SAGn = 1,145,760reference
- Outcome
- Risk-adjusted median survival (long-term survival)
Methodological detailsinstrumental variable analysis, 2-stage residual inclusion
- Instrumental variable analysis
- 2-stage residual inclusion
Main finding
Risk-adjusted median survival, IV model
Difference
0.01 years
By group
As reported in the abstract
Observational data: associations, not effects.
Further findings
Risk-adjusted median survival, non-IV model · non-IV model
difference 0.41
| Outcome | MAG | SAG | Estimate |
|---|---|---|---|
| Surgeon MAG rate in 12 months before index CABG | 32.9% (SD 25.8%) | 7.7% (SD 9.5%) |
Original publication
Multiarterial Grafting and Survival After Coronary Artery Bypass Grafting: An Instrumental Variable Analysis. J Am Coll Cardiol. Published 13 May 2026. doi:10.
Summarised from the published abstract; every number is checked against it