Coronary disease & ACSCohort study

Multiarterial Grafting and Survival After Coronary Artery Bypass Grafting

J Am Coll CardiolPublished

  • Retrospective cohort study
  • instrumental variable analysis
  • 2-stage residual inclusion

Authors' 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)

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

OutcomeMAGSAGEstimate
Surgeon MAG rate in 12 months before index CABG32.9% (SD 25.8%)7.7% (SD 9.5%)

Original publication

Multiarterial Grafting and Survival After Coronary Artery Bypass Grafting. J Am Coll Cardiol. Published 13 May 2026. doi:10.1016/j.jacc.2026.03.044

Summarised from the published abstract; every number is checked against it