Mean platelet volume/platelet count ratio predicts long-term mortality in patients with infective endocarditis

Non-linear relationship between platelet count and 28-day mortality in critically ill patients with infective endocarditis: a retrospective cohort study from MIMIC IV database

Background

The relationship between platelet count and 28-day mortality in critically ill patients with infective endocarditis (IE) is currently not well established.

Objective

This study aims to investigate the impact of platelet count on 28-day mortality in critically ill patients with infective endocarditis.

Methods

A retrospective cohort study was conducted involving 450 participants diagnosed with infective endocarditis and admitted to intensive care units (ICU). Vital signs, laboratory parameters and comorbidity were collected for all participants to analyze the association between platelet count and 28-day mortality. In order to assess the independent association between platelet count and 28-day mortality, we employed multivariable cox hazard regression analyses and smooth curve fitting. A further analysis was conducted using a two-piecewise linear regression model to examine the nonlinear association between platelet count and in-hospital mortality.

Results

A total of 450 critically ill patients with infective endocarditis were included in the study. The mean age was 57.4 years, and 64.2% were male. The overall 28-day mortality rate was 20%. A non-linear relationship was observed between platelet count and 28-day mortality. Two different slopes were identified, with correlations between platelet count and 28-day mortality in patients with IE differing significantly below and above the inflection point, which was approximately 141 K/µl. On the left side of the inflection point, the hazard ratio was 0.990 (hazard ratio: 0.990, 95% confidence interval: 0.982-0.997, p = 0.006). However, on the right side of the inflection point, the hazard ratio increased marginally to 1.0004 (HR: 1.0004, 95% CI: 0.997-1.004, p = 0.825). Notably, the association lacked statistical significance on the right side of the inflection point.

Conclusion

A nonlinear association between platelet count and 28-day mortality was observed in critically ill patients with infective endocarditis. The optimal platelet count associated with the lowest risk of 28-day mortality was above 141 k/µl.

Prognostic significance of mean platelet volume to platelet count ratio in pediatric patients with acute kidney injury

BACKGROUND

Mean platelet volume (MPV), which is regarded as a marker of thrombocyte function and activation, is related to increased morbidity and mortality. In critically ill patients, the ratio of MPV to platelets can independently predict adverse outcomes. This study aimed to investigate the prognostic value of the mean platelet volume/platelet count ratio (MPR) for mortality in children with acute kidney injury (AKI).

METHODS

In this retrospective study, patients hospitalized in the pediatric intensive care unit (PICU) between March 2020 and June 2022 were evaluated. Patients between 1 month and 18 years of age with AKI were enrolled. Clinical and laboratory data were compared between survivors and non-survivors. The MPR ratio was calculated on the first and third days of admission to the intensive care unit. A multiple logistic regression analysis was used to determine the association between MPR and mortality. ROC curves were used for the prediction performance of the logistic regression models and cut-off values of the thrombocyte indices.

RESULTS

Sixty-three children with AKI were included in the study. The total mortality rate was 34.9% (n=22). MPR ratios were significantly higher in the non-survivors at admission (p=0.042) and at the 72nd hour (p=0.003). In the multiple logistic regression analysis, thrombocyte counts and MPR72h ratio were found to be independent risk parameters for adverse outcomes in children with AKI.

CONCLUSIONS

MPR is an inexpensive and practical marker that may predict the outcome of children with AKI.

Mean platelet volume and the association with all-cause mortality and cardiovascular mortality among incident peritoneal dialysis patients

BACKGROUND

While mean platelet volume (MPV) is linked to severity and all-cause mortality in patients with sepsis, its association with all-cause mortality and cardiovascular mortality in patients treated with peritoneal dialysis (PD) remains unknown.

OBJECTIVES

The purpose of this study was to estimate the relationship between MPV and all-cause mortality and cardiovascular mortality among patients treated with PD.

METHOD

We retrospectively collected 1322 patients treated with PD from November 1, 2005 to August 31, 2019. All-cause mortality and cardiovascular mortality was identified as the primary outcome. MPV was classified into three categories by means of X-tile software. The correlation between MPV and all-cause mortality was assessed by Cox model. Survival curves were performed by Kaplan-Meier method.

RESULTS

The median follow-up period was 50 months (30-80 months), and a total of 360 deaths were recorded. With respect to all-cause mortality, patients in MVP ≥ 10.2 fL had considerably higher risk of all-cause mortality among three models (HR 0.68, 95%CI 0.56-0.84; HR 0.70, 95%CI 0.56-0.87; HR 0.73, 95%CI 0.59-0.91; respectively). Moreover, patients treated with PD, whose MVP ≥ 10.2 fL, also suffered from significantly higher risk of cardiovascular mortality in model 1, 2, and 3 (HR 0.63, 95%CI 0.46-0.85; HR 0.66, 95%CI 0.48-0.91; HR 0.69, 95%CI 0.50-0.95; respectively).

CONCLUSIONS

This study indicates that MPV is independently correlated with both all-cause mortality and cardiovascular mortality in PD.

The Role of Platelets in Infective Endocarditis

Over the last decade, the incidence of infective endocarditis (IE) has increased, with a change in the frequency of causative bacteria. Early evidence has substantially demonstrated the crucial role of bacterial interaction with human platelets, with no clear mechanistic characterization in the pathogenesis of IE. The pathogenesis of endocarditis is so complex and atypical that it is still unclear how and why certain bacterial species will induce the formation of vegetation. In this review, we will analyze the key role of platelets in the physiopathology of endocarditis and in the formation of vegetation, depending on the bacterial species. We provide a comprehensive outline of the involvement of platelets in the host immune response, investigate the latest developments in platelet therapy, and discuss prospective research avenues for solving the mechanistic enigma of bacteria-platelet interaction for preventive and curative medicine.

Effect of Mean Platelet Volume to Platelet Count Ratio on Mortality in Peritoneal Dialysis

Background and Aims

Mean platelet volume to platelet count ratio (MPV/PC) has been found to be an independent risk factor for mortality in various diseases, including cardiovascular disease, cancer, and hemodialysis. We aimed to evaluate the association between MPV/PC and all-cause and cardiovascular (CV) mortality in peritoneal dialysis (PD) patients.

Methods and Results

We conducted a retrospective cohort study at a single center and enrolled 1473 PD patients who were catheterized at our PD center from January 1, 2006, to December 31, 2013. All patients were divided into four groups according to the quartiles of baseline MPV/PC levels and followed up until December 31, 2018. A total of 453 patients died, and 221 deaths were caused by cardiovascular disease during a median follow-up time of 48.0 (21.9-82.2) months. There was a significant interaction by age of association between MPV/PC level and all-cause mortality (P = 0.009), and multivariate Cox regression analysis showed that higher MPV/PC level was related to a decreased risk of all-cause and CV mortality in PD patients aged < 60 years (HR = 0.62, 95%CI = 0.40 − 0.96, P = 0.032; HR = 0.49, 95%CI = 0.26 − 0.93, P = 0.029, respectively), rather than in patients aged ≥ 60 years (HR = 1.37, 95%CI = 0.84 − 2.22, P = 0.208; HR = 1.50, 95%CI = 0.77 − 2.92, P = 0.237, respectively).

Conclusion

Our results indicated that low MPV/PC level was an independent risk factor for all-cause and CV mortality in PD patients aged less than 60 years.

Lower Platelet-to-Lymphocyte Ratio Was Associated with Poor Prognosis for Newborn Patients in NICU

Background: Platelet-to-lymphocyte ratio (PLR) is reported to be related to the outcome of intensive care unit (ICU) patients. However, little is known about their associations with prognosis in newborn patients in neonatal ICU (NICU). The aim of the present study was to investigate the prognostic significance of the PLR for newborn patients in the NICU. Methods: Data on newborn patients in the NICU were extracted from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC III) database. The initial PLR value of blood examinations within 24 h was analyzed. Spearman's correlation was used to analyze the association of PLR with the length of hospital and ICU stays. The chi-square test was used to analyze the association of PLR with mortality rate. Multivariable logistic regression was used to determine whether the PLR was an independent prognostic factor of mortality. The area under the receiver operating characteristic (ROC) curve was used to assess the predictive ability of models combining PLR with other variables. Results: In total, 5240 patients were enrolled. PLR was negatively associated with length of hospital stay and ICU stay (hospital stay: ρ = −0.416, p < 0.0001; ICU stay: ρ = −0.442, p < 0.0001). PLR was significantly correlated with hospital mortality (p < 0.0001). Lower PLR was associated with higher hospital mortality (OR = 0.85, 95% CI = 0.75−0.95, p = 0.005) and 90-day mortality (OR = 0.85, 95% CI = 0.76−0.96, p = 0.010). The prognostic predictive ability of models combining PLR with other variables for hospital mortality was good (AUC for Model 1 = 0.804, 95% CI = 0.73−0.88, p < 0.0001; AUC for Model 2 = 0.964, 95% CI = 0.95−0.98, p < 0.0001). Conclusion: PLR is a novel independent risk factor for newborn patients in the NICU.

A risk scoring system integrating postoperative factors for predicting early mortality after major non-cardiac surgery

We aimed to develop a risk scoring system for 1-week and 1-month mortality after major non-cardiac surgery, and assess the impact of postoperative factors on 1-week and 1-month mortality using machine learning algorithms. We retrospectively reviewed the medical records of 21,510 patients who were transfused with red blood cells during non-cardiac surgery and collected pre-, intra-, and postoperative features. We derived two patient cohorts to predict 1-week and 1-month mortality and randomly split each of them into training and test cohorts at a ratio of 8:2. All the modeling steps were carried out solely based on the training cohorts, whereas the test cohorts were reserved for the evaluation of predictive performance. Incorporation of postoperative information demonstrated no significant benefit in predicting 1-week mortality but led to substantial improvement in predicting 1-month mortality. Risk scores predicting 1-week and 1-month mortality were associated with area under receiver operating characteristic curves of 84.58% and 90.66%, respectively. Brain surgery, amount of intraoperative red blood cell transfusion, preoperative platelet count, preoperative serum albumin, and American Society of Anesthesiologists physical status were included in the risk score predicting 1-week mortality. Postoperative day (POD) 5 (neutrophil count × mean platelet volume) to (lymphocyte count × platelet count) ratio, preoperative and POD 5 serum albumin, and occurrence of acute kidney injury were included in the risk score predicting 1-month mortality. Our scoring system advocates the importance of postoperative complete blood count differential and serum albumin to better predict mortality beyond the first week post-surgery.

Molecular characterization and expression of RPS23 and HPSE and their association with hematologic parameters in sheep

Ribosomal protein S23 (RPS23) and Heparanase (HPSE) were located on chromosome 5 and chromosome 6, respectively, which play vital roles in protein synthesis and immunity. The objective of this study was to clone RPS23 and HPSE and to detect the expression levels of RPS23 and HPSE and the polymorphisms of RPS23 and HPSE associated with the hematologic parameters by using qRT-PCR, DNA sequencing and KASPar assay. The quantitative real-time PCR (RT-qPCR) showed that the two genes were expressed widely in the ten tissues of sheep. The expression levels of RPS23 and HPSE were the highest in lung and liver, respectively. The expression levels of RPS23 and HPSE in lung and liver increased from 0 to 3 months, decreased from 3 to 6 months, respectively. Furthermore, two mutations g.720 A > G and g.1077 G > A were detected in the RPS23 and HPSE, respectively, which were confirmed to be significantly associated with hematologic parameters. These results supported RPS23 g.720 A > G and HPSE g.1077 G > A as genetic markers of sheep.