Sex Differences in All-Cause Mortality in the Decade Following Complex Coronary Revascularization

Background: The poorer prognosis of coronary artery disease in females compared with males is related mainly to differences in baseline characteristics. In the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) trial, the effect of treatment with percutaneous coronary intervention (PCI) versus coronary artery bypass grafting surgery (CABG) on mortality at 5 years differed significantly between females and males; however, the optimal revascularization beyond 5 years according to sex has not been evaluated.

Objectives: The aim of this study was to investigate the impact of sex on mortality and sex-treatment interaction at 10 years.

Methods: The SYNTAXES (SYNTAX Extended Survival) study evaluated vital status up to 10 years in 1,800 patients with de novo 3-vessel and/or left main coronary artery disease randomized to treatment with PCI or CABG in the SYNTAX trial. All-cause death at 10 years was separately evaluated in female and male patients with complex coronary artery disease.

Results: Of 1,800 patients, 402 (22.3%) were female and 1,398 (77.7%) were males. Females had a higher 10-year mortality rate compared with males (32.8% vs. 24.7%; log-rank p = 0.002), but female sex was not an independent predictor of mortality (adjusted hazard ratio: 1.02; 95% confidence interval: 0.76 to 1.36). Mortality at 10 years tended to be lower after CABG than after PCI, with a similar treatment effect for female and male patients (adjusted hazard ratio for females: 0.90 [95% confidence interval: 0.54 to 1.51]; adjusted hazard ratio for males: 0.76 [95% confidence interval: 0.56 to 1.02]; p for interaction = 0.952).

Conclusions: Female sex was not an independent predictor of mortality at 10 years in patients with complex coronary artery disease. The interaction between sex and treatment with PCI or CABG that was observed at 5 years was no longer present at 10 years. (Synergy Between PCI With TAXUS and Cardiac Surgery: SYNTAX Extended Survival [SYNTAXES], NCT03417050; SYNTAX Study: TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries [SYNTAX], NCT00114972).