Aims: The aim of this investigation was to determine the incidence and multivariable correlates of long-term (4-year) mortality in patients treated with surgical or percutaneous revascularization in the synergy between percutaneous coronary intervention (PCI) with TAXUS Express and Cardiac Surgery (SYNTAX) trial.
Methods and results: A total of 1800 patients were randomized to undergo coronary artery bypass graft (CABG) surgery (n = 897) or PCI (n = 903). Prospectively collected baseline and peri- and post-procedural data were used to determine independent correlates of 4-year all-cause death in the CABG and the PCI arms (Cox proportional hazards model). Four-year mortality rates in the CABG and the PCI arms were 9.0% [74 deaths (12 in-hospital)] and 11.8% [104 deaths (16 in-hospital)], respectively (log-rank P-value = 0.063). Censored data comprised 78 patients (8.7%) in the CABG arm, and 24 patients (2.7%) in the PCI arm (log-rank P-value < 0.001). Within the CABG arm, the strongest independent correlates of 4-year mortality were lack of discharge aspirin [hazard ratio (HR) 3.56; 95% CI: 2.04, 6.21; P < 0.001], peripheral vascular disease (PVD) (HR: 2.65; 95% CI: 1.49, 4.72; P = 0.001), chronic obstructive pulmonary disease, age, and serum creatinine. Within the PCI arm, the strongest independent correlate of 4-year mortality was lack of post-procedural anti-platelet therapy (HR: 152.16; 95% CI: 53.57, 432.22; P < 0.001), with 10 reported early (within 45 days) in-hospital deaths secondary to multifactorial causes precluding administration of anti-platelet therapy. Other independent correlates of mortality in the PCI arm included amiodarone therapy on discharge, pre-procedural poor left ventricular ejection fraction, a 'history of gastrointestinal bleeding or peptic ulcer disease', PVD (HR: 2.13; 95% CI: 1.26, 3.60; P = 0.005), age, female gender (HR: 1.60; 95% CI: 1.01, 2.56; P = 0.048), and the SYNTAX score (Per increase in 10 points: HR: 1.25; 95% CI: 1.06, 1.47; P = 0.007).
Conclusion: Independent correlates of 4-year mortality in the SYNTAX trial were multifactorial. Lack of discharge aspirin and lack of post-procedural anti-platelet therapy were the strongest independent correlates of mortality in the CABG and the PCI arms, respectively. Peripheral vascular disease is a common independent correlate of 4-year mortality and may be a marker of the severity of baseline coronary disease and risk of future native coronary disease (and extra-cardiac disease) progression.