Age-dependent impact of the SYNTAX-score on longer-term mortality after percutaneous coronary intervention in an all-comer population

BACKGROUND: The Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX)-score is a validated tool for risk stratification and revascularization strategy selection in patients with complex coronary artery disease. The aim of this study was to analyse its age-related prognostic value. METHODS: SYNTAX-score was calculated in 1331 all-comer patients undergoing percutaneous coronary intervention (PCI): 463 patients ≥ 75 years and 868 patients < 75 years. Outcomes of interest were all-cause mortality at one and two years. RESULTS: A significant interaction of age and SYNTAX-score for mortality was observed at two-year (P(interaction) = 0.019) but not at one-year follow-up (P(interaction) = 0.594). In multivariable analysis, SYNTAX-score independently predicted 1-year mortality in both age groups (< 75 years, hazard ratio (HR): 1.43, 95% confidence intervals (CI): 1.03–2.00, P = 0.034; and ≥ 75 years, HR: 1.37, 95% CI: 1.01–1.85, P = 0.042), but only two-year mortality among younger patients (< 75 years, HR: 1.33, 95% CI: 1.01–1.76, P = 0.041; and ≥ 75 years, HR: 1.11, 95% CI: 0.87–1.41, P = 0.394). SYNTAX-score tertiles were useful to stratify 1-year mortality in both, patients < 75 years (SYNTAX-score < 9, 3.8%; 9–20, 5.3%; ≥ 20, 10.3%; P = 0.004) and ≥ 75 years (SYNTAX-score < 11, 5.7%; 11–22.5, 16.1%; ≥ 22.5, 18.7%; P = 0.003), but two-year mortality only among patients < 75 years (SYNTAX-score < 9, 6.5%; 9–20, 7.6%; ≥ 20, 15%; P < 0.001) and not among ≥ 75 years old patients (SYNTAX-score < 11, 19.4%; 11–22.5, 26.3%; ≥ 22.5, 27.9%; P = 0.138). CONCLUSIONS: Age modifies the impact of the SYNTAX-score on longer-term mortality after PCI. Among patients < 75 years, the SYNTAX-score independently predicts the risk of death at one and two years after PCI, while among patients ≥ 75 years its predictive role is limited to the first year after PCI. Further studies are needed to evaluate the value of SYNTAX-score for selecting the most appropriate revascularization strategy among elderly patients.