Sean C. Hardiman, MHA, CHE, FACHE: No financial relationships to disclose
Background: Prior research has shown that patients with stable ischemic heart disease who undergo delayed isolated coronary artery bypass graft (CABG) surgery face higher mortality rates than those who receive isolated CABG within the time recommended by physicians. However, this research did not account for percutaneous coronary intervention (PCI), a widely available alternative to delayed CABG in many settings. We sought to establish whether there was a difference in mortality between timely PCI and delayed CABG.
METHODS AND RESULTS: We linked BC's diagnostic catheterization, PCI, and CABG databases to the Ministry of Health's Discharge Abstract Database and the Vital Statistics Deaths file to construct care episodes containing all events during the revascularization journey. We identified 25,520 BC residents 60 years or older who underwent first-time non-emergency revascularization for angiographically-proven, stable left main or multi-vessel ischemic heart disease in British Columbia between January 1, 2001, and December 31, 2016. Patients were assigned to the delayed CABG or timely PCI treatment groups according to the Canadian Cardiovascular Society's Access to Care guidelines. The start date of the time to treatment period was the date clinical need for revascularization was established and the patient was ready, willing, and able to have the procedure. The end date was the date revascularization was performed. Time to outcome was measured from index revascularization (CABG and single-session PCI) or last staged PCI to death, study end, or three years' follow-up. We estimated unadjusted and adjusted mortality after index revascularization or last staged PCI and calculated risk ratios. Adjustment was performed using inverse probability of treatment weights calculated from a propensity score model that contained patient, structure, and process factors identified from the literature.
Before adjustment, the 3-year mortality rate was 5.9% in the delayed CABG group and 12.1% in the timely PCI group (risk ratio [RR] 0.48, 95% confidence interval [CI], 0.43 – 0.53). After adjustment with inverse probability of treatment weights, at three years, patients who underwent delayed CABG had a statistically significant lower mortality compared with patients who received timely PCI (4.3% delayed CABG, 13.5% timely PCI; RR 0.32, 95% CI 0.24 – 0.40).
Conclusion: Patients who undergo CABG with delay have a lower risk of death than patients who undergo PCI within appropriate time. Our results suggest that patients who wish to receive CABG as their revascularization treatment will receive a mortality benefit over PCI as an alternative strategy should their CABG treatment be delayed.
