Background: The incidence of acute coronary syndrome (ACS) in young people (≤65 years) is continuously rising. While prognostic factors in ACS are well-investigated less attention has been paid to their age-dependent prognostic value and their particular relevance in younger patients. The aim of our study was to assess the age-dependent prognostic impact of butyrylcholinesterase (BChE).
Methods: Retrospective cohort study including 624 patients with ACS. Patients were stratified by age into equal groups (n = 208) corresponding to "young patients" (45-64 years), "middle-aged patients" (65-84 years) and "old patients" (85-100 years). Cox regression hazard analysis was used to assess the influence of BChE on survival.
Results: After a mean follow-up time of 4.0 (interquartile range [IQR] 2.0-6.4) years, 154 patients (24.7%) died due to a cardiac cause. In the overall cohort, BChE was indirectly associated with cardiac mortality-free survival (adjusted hazard ratio (HR): 0.70 (95% confidence interval [CI] 0.53-0.93, p = 0.01). The primary-analysis of BChE by age strata showed the strongest effect in the age group 45-64 years with an adjusted HR per 1-SD of 0.28 (95% CI 0.12-0.64, p = 0.003), a weaker association with mortality in middle aged (65-84 years: adjusted HR per 1-SD 0.66 [95% CI: 0.41-1.06], p = 0.087), and no association in older patients (85-100 years: adjusted HR per 1-SD 0.89 [95% CI: 0.58-1.38], p = 0.613).
Conclusion: BChE is a strong predictor for cardiac mortality specifically in younger patients with ACS aged between 45 and 64 years. No significant association of BChE with cardiac-mortality was detected in other age classes.