The age-specific prognostic impact of the platelet-to-lymphocyte ratio on long-term outcome after acute coronary syndrome

AIMS: Personalized risk stratification within the ageing society after acute coronary syndrome (ACS) remains scarce but in urgent need. Increased platelet activity together with inflammatory activation play a key role during ACS. We aimed to evaluate the age-specific prognostic potential of the platelet to lymphocyte ratio (PLR) on long-term cardiovascular mortality after ACS. METHODS AND RESULTS: Patients presenting with ACS admitted to the Vienna General Hospital between December 1996 and January 2010 were enrolled within a clinical registry including assessment of peripheral blood samples. The impact of the PLR on survival was assessed by Cox-regression hazard analysis. We included a total of 681 patients with a median age of 64 years (interquartile range: 45–84). Two hundred (29.4%) individuals died during the median follow-up time of 8.5 years. A strong and independent association of the PLR with cardiovascular mortality was found in the total study population [adjusted (adj.) hazard ratio (HR) per 1 standard deviation (1 SD) of 1.07 (95% confidence interval, CI: 1.03–1.10); P < 0.001]. After stratification in individuals <65 years (n = 339) and ≥65 years (n = 342), a prognostic effect of the PLR on cardiovascular mortality was solely observed in elderly patients ≥65 years [adj. HR per 1 SD of 1.04 (95% CI: 1.00–1.08); P = 0.039], but not in their younger counterparts <65 years [adj. HR per 1 SD of 0.97 (95% CI: 0.83–1.14); P = 0.901]. CONCLUSION: The present investigation highlights a strong and independent age-specific association of the PLR with cardiovascular mortality in patients with ACS. The PLR only allows to identify patients ≥65 years at high risk for fatal events after ACS—even from a long-term perspective.