Background The predictive value of platelet indices, including the platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT), and platelet–lymphocyte ratio (PLR) for postoperative atrial fibrillation (POAF) following cardiac surgery remains undetermined. Methods MEDLINE, Embase, and the Cochrane Library were searched from inception to October 2024. For each included study, median differences (MDs) and odds ratios (ORs) were tabulated with 95% confidence intervals (CIs). Pooled estimates were generated using random‐effects inverse‐variance modeling. Statistical analysis focused on cases of POAF. Results Six thousand five hundred and seventeen unique studies were screened and included 23 studies involving 12,375 patients in the subsequent analysis. Compared with patients who did not develop POAF, patients with POAF had higher preoperative MPV (MD: 0.30 fL, 95% CI: 0.07–0.53, and p = 0.0112) and PLR (MD: 40.42, 95% CI: 7.49–73.33, and p = 0.0161). Preoperative PLT (MD: 3.32, 95% CI: −5.87–12.51, and p = 0.4785) was not significantly different between groups. Study numbers were insufficient to assess the association between PCT with POAF. Conclusion Elevated preoperative MPV and PLR were associated with POAF after cardiac surgery. Further research is required to investigate the roles of these indices in the risk stratification of POAF in patients undergoing cardiac surgery.

Background: The role of routinely available platelet biomarkers – platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) – is poorly understood in osteoarthritis (OA). This systematic review and meta-analysis aimed to assess the association between platelet biomarkers and the occurrence and severity of OA. Methods: MEDLINE, Embase and the Cochrane libraries were searched from inception to June 2025. We included studies reporting on the association between PLT, MPV, PDW and PCT with the presence and severity of OA. We tabulated mean differences (MDs) of platelet biomarkers between patients with OA against healthy controls, as well as between patients with severe OA and mild/moderate OA to generate pooled effect measures using random-effects inverse variance modelling. Results: Fourteen studies, with a total of 13 843 patients, were included in this systematic review. Mean platelet volume (fL) was significantly reduced in OA as compared to healthy controls, MD = −0.52 (95% CI: −0.65 to −0.39, P < .01). Platelet count was not significantly different between the groups, MD = 2.32 (95% CI: −6.29 to 10.94, P = .60). Both PLT and MPV were not significantly different between the 2 groups, with pooled mean differences of 3.57 (95% CI = −8.21 to 15.35, P = .55) and 0.37 (95% CI = −0.33 to 1.08, P = .30), respectively. Conclusions: This meta-analysis found MPV to be significantly reduced in OA. Further studies are needed to further evaluate the prognostic significance of mean platelet volume in OA.

RED CELL DISTRIBUTION WIDTH (RDW) is a routinely available biomarker of likely erythropoietic dysfunction, which may be associated with adverse outcomes after cardiac surgery. This systematic review and meta-analysis aimed to clarify the prognostic value of RDW in patients undergoing cardiac surgery. The authors searched MEDLINE, Embase, and the Cochrane Library from inception to May 10, 2022 for studies investigating the association between elevated RDW (as defined by the authors of included studies) and adverse outcomes after cardiac surgery. Herein, the authors extracted maximally adjusted hazard ratios (HRs) and odds ratios (ORs) with associated CIs, and pooled them using random-effects inverse- variance modeling. The authors explored interstudy heterogeneity using metaregression. The authors included 26 studies involving 48,092 patients who had undergone cardiac surgery. Elevated preoperative RDW was associated with long-term mortality (pooled HR 1.63, 95% CI 1.05-2.52), short-term mortality (pooled OR 2.16, 95% CI 1.21-3.87), acute kidney injury (AKI; pooled OR 1.30, 95% CI 1.19-1.41) and postoperative atrial fibrillation (POAF; pooled OR 1.44, 95% CI 1.05-1.96). Some studies suggested a significant association between preoperative RDW elevation and neurologic complications; however, their number was insufficient for meta-analysis. The postoperative RDW levels were less consistently reported and could not be meta-analyzed. In conclusion, the authors found that elevated preoperative RDW was associated with increased short- and long-term mortality, POAF, and AKI after cardiac surgery. Further research is needed to investigate its role in the risk stratification of patients undergoing cardiac surgery.

Background: The neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and red cell distribution width (RDW) are routinely available inflammatory biomarkers. Their significance in osteoarthritis (OA) is poorly understood. This is a systematic review, and meta-analysis aimed to determine the association of these biomarkers with the presence and severity of OA. Methods: We searched MEDLINE, EMBASE, and Cochrane library for studies reporting on associations between NLR, PLR, and RDW with OA from October 1, 2022, to November 18, 2022. We generated pooled effect measures using random-effects inverse-variance modeling to compare biomarker levels in patients with OA against healthy controls. We generated pooled effect measures to compare patients with severe OA against mild/moderate OA as defined by the Kellgren-Lawrence grading scale, a classification of OA severity based on radiographic findings. We performed metaregression to explore between-study heterogeneity. Results: We included 20 studies involving 5,109 patients in this review. Both NLR and PLR were significantly elevated in OA. RDW was not significantly elevated with OA presence or severity. Only NLR demonstrated a significant elevation with OA severity. Conclusions: In this systematic review and meta-analysis, both NLR and PLR were associated with the presence of OA, whereas only NLR was associated with the severity of disease.

Background Hyperbilirubinemia following cardiac surgery is a common phenomenon and is of emerging interest in prognostic factor research. This systematic review and meta-analysis evaluated the association between post-operative hyperbilirubinemia (PH) and mortality and morbidity in cardiac surgery patients. Methods Ovid Medline and Ovid Embase were searched from inception to July 2020 for studies evaluating the prognostic significance of PH following cardiac surgery. Maximally adjusted odds ratios (OR) with associated confidence intervals were obtained from each study and pooled using random effects inverse variance modelling to assess in-hospital mortality. Standardised mean differences were pooled to assess Intensive Care Unit (ICU) and hospital length of stay (LOS). Qualitative analysis was performed to assess ventilation requirements and long-term mortality. Meta-regression was used to assess inter- and intra-study heterogeneity. Results 3251 studies satisfied the selection criteria, from which 12 studies incorporating 3876 participants were included. PH significantly predicted in-hospital mortality with a pooled OR of 7.29 (95% CI 3.53, 15.09). Multiple pre-defined covariates contributed to the prognostic significance of PH, however only aortic cross-clamp time ( p < 0.0001) and number of transfusions ( p = 0.0001) were significant effect modifiers. PH significantly predicted both ICU LOS (Mean difference 1.32 [95% CI 0.04–2.6]) and hospital LOS (Mean difference 1.79 [95% CI 0.36–3.21]). Qualitative analysis suggested PH is associated with increased post-operative ventilation requirements and reduced long-term survival rates. Conclusions Hyperbilirubinemia is a cost-effective, widely available prognostic marker of adverse outcomes following cardiac surgery, albeit with residual sources of heterogeneity.

The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are emerging haematological inflammatory biomarkers. However, their significance in retinal vein occlusion (RVO) and its subtypes, branch and central RVO (BRVO and CRVO, respectively), is uncertain. This systematic review and meta-analysis aimed to clarify the association of NLR and PLR with RVO. We searched MEDLINE (Ovid), EMBASE (Ovid) and the Cochrane Library for studies investigating the association of NLR and PLR with RVO from inception to 2 December 2020. We used random-effects inverse-variance modelling to generate pooled effect measures. We used bivariate Bayesian modelling to meta-analyse the ability of NLR and PLR to differ between individuals with and without RVO and performed meta-regression and sensitivity analyses to explore inter-study heterogeneity. Eight studies published encompassing 1059 patients were included for analysis. Both NLR and PLR were significantly elevated in RVO, with pooled mean differences of 0.63 (95% confidence interval (CI) 0.31-0.95) and 21.49 (95% CI 10.03-32.95), respectively. The pooled sensitivity, specificity and area under the Bayesian summary receiver operating characteristic curve were, respectively, 0.629 (95% credible interval (CrI) 0.284-0.872), 0.731 (95% CrI 0.373-0.934) and 0.688 (95% CrI 0.358-0.872) for NLR; and 0.645 (95% CrI 0.456-0.779), 0.616 (95% CrI 0.428-0.761) and 0.621 (95% CrI 0.452-0.741) for PLR. Mean and variability of age and diabetes mellitus prevalence partially explained between-study heterogeneity. NLR and PLR are significantly elevated in RVO. Future research is needed to investigate the potential prognostic value and independence of these findings.