This study aimed to investigate the potential prognostic role of the platelet-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). A systematic search of PubMed Central, Scopus, EMBASE, and the Cochrane Library from conception through 20 August 2023 was conducted. We used odds ratios (OR) as the effect measure with 95% confidence intervals (CIs) for dichotomous data and mean differences (MD) with a 95% CI for continuous data. If I2 was less than 50% or the p value of the Q tests was less than 0.05, a random synthesis analysis was conducted. Otherwise, a fixed pooled meta-analysis was performed. Nineteen studies fulfilled the eligibility criteria and were included in the meta-analysis. PLR was higher in MACE-positive (164.0 ± 68.6) than MACE-negative patients (115.3 ± 36.9; MD = 40.14; 95% CI: 22.76 to 57.52; p < 0.001). Pooled analysis showed that PLR was higher in AMI patients who died (183.3 ± 30.3), compared to survivors (126.2 ± 16.8; MD = 39.07; 95% CI: 13.30 to 64.84; p = 0.003). It was also higher in the ACS vs. control group (168.2 ± 81.1 vs. 131.9 ± 37.7; MD = 39.01; 95% CI: 2.81 to 75.21; p = 0.03), STEMI vs. NSTEMI cohort (165.5 ± 92.7 vs. 159.5 ± 87.8; MD = 5.98; 95% CI: -15.09 to 27.04; p = 0.58), and MI vs. UAP populations (162.4 ± 90.0 vs. 128.2 ± 64.9; MD = 18.28; 95% CI: -8.16 to 44.71; p = 0.18). Overall, our findings confirmed the potential prognostic role of the plate-let-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). Its use as a risk stratification tool should be examined prospectively to define its capability for evaluation in cardiovascular patients.
Keywords: PLR; acute coronary syndrome; biomarker; diagnostic; meta-analysis; platelet-to-lymphocyte ratio.