The age-specific prognostic impact of the platelet-to-lymphocyte ratio on long-term outcome after acute coronary syndrome
Niema Kazem, Felix Hofer, Lorenz Koller, Andreas Hammer, Thomas M. Hofbauer, Christian Hengstenberg, Alexander Niessner, Patrick Sulzgruber
Abstract
Abstract 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.