Abstract 12: Determinants of Health-Related Quality of Life after Percutaneous Coronary Intervention or Bypass Surgery: Insights from the SYNTAX Trial

Background: Patients with multivessel or left main CAD treated with CABG have a small but significant improvement in angina as compared to those treated with PCI. However, there is uncertainty as to the mechanism of greater angina relief with CABG and whether the greater need for repeat revascularization in PCI patients could account for this treatment difference. Methods: In the SYNTAX trial, 1800 patients with three-vessel or left main CAD were randomized to CABG (n=897) or PCI with paclitaxel-eluting stents (n=903). Health-related quality of life was assessed at baseline, 1, 6, and 12 months using the Seattle Angina Questionnaire and the SF-36 General Health Survey. Longitudinal random effect growth curve models were used to examine the association between patient-related factors, treatment-related factors, clinical outcomes, and follow-up health status. Results: Older age, male sex, and absence of angina at baseline were associated with less angina at 12 months, whereas completeness of revascularization was not. The need for repeat revascularization was associated with worse angina frequency scores in both treatment groups, with differences in PCI patients of 7.8 points at 6 months (p<0.001) and 2.9 points at 12 months (p=0.07) and in CABG patients of 16.4 points at 6 months (p<0.001) and 9.1 points at 12 months (p<0.001). Among patients who did not require repeat revascularization, the effect of CABG vs. PCI on 12-month angina frequency scores was 1.6 points–nearly identical to the overall benefit in the intention-to-treat analysis. Conclusions: Patients with multivessel or left main CAD who required repeat revascularization had substantially worse angina and overall health status during follow-up. However, this factor explained little of the treatment benefit observed with CABG over PCI in the overall population, suggesting that some of the anti-anginal benefit of CABG may result from mechanisms unrelated to relief of myocardial ischemia. In addition, there was a substantial difference in the magnitude of association between repeat revascularization and anginal status in patients treated with CABG as compared with PCI, suggesting that this endpoint should play a limited role in any direct comparison of the two treatment strategies.