Growth differentiation factor 15 and geriatric conditions in acute coronary syndrome.

Background: Growth differentiation factor 15 (GDF-15) is a marker of cell senescence. Age is awell-known determinant of GDF-15 levels, yet no study has analyzed the relationship between geriatric conditions and GDF-15. We hypothesize that geriatric conditions reflecting biological age might be stronger determinants of GDF-15 than chronological age in elderly patients with acute coronary syndrome. Methods: A total of 208 patients (mean age=78.3±7.0 years) were included. Prior to discharge, a thorough geriatric assessment was performed and GDF-15 measured. Predictors of GDF-15 (transformed by its natural logarithm) were determined with linear regression. Furthermore, Cox regression was used for the analysis of allcause mortality. The median follow-up was 728 days. Results: Median GDF-15 concentration was 2432 pg/ml. In multivariate analysis, frailty (Fried score, p=0.001), and comorbidity (Charlson index, p = 0.003) were independent determinants of lnGDF-15 while age was not significant (p = 0.17). Other covariates included in the model were male gender (p = 0.017), diabetes (p = 0.169), Killip class ≥2 (p = 0.046) and glomerular filtration rate (p = 0.001). The Fried score and Charlson index provided significant incremental value in the R2 model (0.362 vs 0.447; p = 0.0001). A total of 66 (32%) patients died. LnGDF-15 was a significant mortality predictor (HR = 1.82, 95% CI 1.12-2.94, p = 0.015) along with the Fried score (p = 0.013) and the Charlson index (p=0.030). Conclusions: Geriatric conditions are strong determinants of GDF-15 levels on top of age in acute coronary syndromes. Furthermore, GDF-15 was associated with mortality independently of geriatric status. Geriatric assessment and GDF-15 are complementary tools.