Background: Platelet-to-lymphocyte ratio (PLR) is a haematological index which reflects increased level of inflammation and thrombosis. We aimed to summarize the potential prognostic role of PLR for the in-hospital and long-term outcomes in ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (pPCI) in a meta-analysis.
Materials and methods: Relevant cohort studies were identified by search the PubMed, Cochrane's Library and Embase databases. A random-effect model was applied to pool the results. In-hospital and long-term outcomes were compared between patients with higher and lower preprocedural PLR.
Results: Eleven cohorts with 12 619 patients were included. Pooled results showed that higher preprocedural PLR was independently associated with increased risk of in-hospital major adverse cardiovascular events (MACE, risk ratio [RR]: 1.76, 95% confidence interval [CI]: 1.39 to 2.22, P < .001; I2 = 49%), cardiac mortality (RR: 1.91, 95% CI: 1.18 to 3.09, P = .009; I2 = 0), all-cause mortality (RR: 2.14, 95% CI: 1.52 to 3.01, P < .001, I2 = 24%) and no reflow after pPCI (RR: 2.22, 95% CI: 1.70 to 2.90, P < .001, I2 = 59%). Moreover, higher preprocedural PLR was associated with increased risk of MACE (RR: 1.60, 95% CI: 1.25 to 2.03, I2 = 57%, P < .001) and all-cause mortality (RR: 2.36, 95% CI: 1.53 to 3.66, I2 = 78%, P < .001) during long-term follow-up of up to 82 months after discharge.
Conclusions: Higher PLR predicts poor in-hospital and long-term prognosis in STEMI patients after pPCI.
Keywords: ST-segment elevation myocardial infarction; major adverse cardiovascular events; meta-analysis; mortality; platelet-to-lymphocyte ratio; primary percutaneous coronary intervention.
© 2020 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.