Immature platelet fraction over time and clinical outcomes in patients with acute myocardial infarction

Immature Platelet Fraction and Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Implantation

INTRODUCTION

Immature platelets or reticulated platelets are newly released thrombocytes. They can be identified by their large size and high RNA cytoplasm concentration. Immature platelet fraction (IPF) represents the percentage of immature circulative platelets relative to the total number of platelets. The role of IPF in patients undergoing transcatheter aortic valve implantation (TAVI) is unknown. The aim of the current trial was to assess the levels of IPF in patients undergoing TAVI and correlation with clinical outcomes.

MATERIAL AND METHODS

Immature platelet fraction levels were measured 3 times in all patients (preprocedure, 1-2 days post-procedure and 1-month post-procedure). Immature platelet fraction measurement was carried out using an autoanalyzer (Sysmex XE-2100). Patients were followed for 12 months. Primary outcomes were defined as complications during hospitalizations, rehospitalization, and mortality.

RESULTS

Fifty-one patients were included in the study. Mean age was 79.8 (±9.6), and 28 (55%) were women. Twenty-one patients (41%) had complications: Of them, 6 of 21 (29%) occurred during hospitalizations (2-vascular complications; 2-sepsis, 2-implantation of a pacemaker), 9 of 21 (43%) patients were rehospitalized after the index admission, and 6 patients died during the follow-up period. Multivariate Cox regression analysis found that IPF < 7% in at least one of the 3 tests was associated with worse outcomes (hazard ratio 3.42; 95% CI 1.11-10.5, P = .032).

CONCLUSION

Immature platelet fraction >7% in patients undergoing TAVI is associated with worse outcomes. Further studies are needed to better understand this phenomenon.

Correlation between baseline immature platelets fraction levels and peak troponin in patients with acute myocardial infarction

INTRODUCTION

Elevated peak cardiac troponin levels have been linked with increased morbidity and mortality in patients with acute myocardial infarction (AMI). Immature Platelets are young and relatively large platelets that are hyper-reactive and pro-thrombotic compared to regular platelets. Increased immature platelet fraction (IPF) has been associated with an elevated risk of thrombotic events. We hypothesize that patients with higher IPF levels during AMI, will experience a more severe infarct, leading to elevated peak troponin levels.

METHODS

Clinical data from patients admitted to the cardiology division between 2018 and 2022, who were diagnosed with AMI and underwent an IPF testing. Univariate and multivariate regression analyses were performed to identify predictors of elevated peak troponin.

RESULTS

Among the 277 patients diagnosed with AMI who underwent IPF testing, 113 had (STEMI) and 164 had (NSTEMI). The median value of IPF of 4.2% was used as the threshold for defining elevated IPF. Notably, among STEMI patients, those with IPF ≥ 4.2% had significantly higher peak troponin levels ( P  = 0.021). Conversely, no significant difference in peak troponin levels was observed among NSTEMI patients ( P  = 0.348). Multivariate analysis identified patients with STEMI in the higher IPF group as one of the significant predictors for elevated peak troponin levels.

CONCLUSION

This study revealed a correlation between higher baseline IPF levels and increased peak troponin levels specifically in STEMI patients, while no such association was found in NSTEMI patients. Incorporating IPF levels above the median into risk stratification scores for STEMI patients may provide valuable support for adopting a more proactive therapeutic approach.

Appetite Predicts Long-Term Clinical Outcomes in Patients with Acute Myocardial Infarction

BACKGROUND

Recently, the nutritional status of patients has drawn attention in an aging society. Early studies have reported that nutritional status is related to long-term outcomes in patients with acute myocardial infarction (AMI). However, it is not necessarily simple to evaluate the nutritional status of patients with AMI. We hypothesized that appetite before discharge can be a predictor for long-term adverse cardiovascular events in patients with AMI. This retrospective study aimed to investigate whether appetite is related to long-term adverse outcomes in patients with AMI.

METHODS

This study included 1006 patients with AMI, and divided them into the good appetite group (n = 860) and the poor appetite group (n = 146) according to the percentage of the dietary intake on the day before discharge. Major adverse cardiac events (MACE), which were defined as a composite of all-cause death, non-fatal MI, and re-admission for heart failure, were set as the primary outcome.

RESULTS

The median follow-up duration was 996 days, and a total of 243 MACE was observed during the study period. MACE was more frequently observed in the poor appetite group than in the good appetite group (42.5% versus 21.0%, p < 0.001). In the multivariate COX hazard model, poor appetite was significantly associated with MACE (Hazard ratio 1.698, 95% confidence interval 1.243-2.319, p < 0.001) after controlling for multiple confounding factors.

CONCLUSION

Appetite at the time of discharge was significantly associated with long-term clinical outcomes in patients with AMI. Patients with poor appetite should be carefully followed up after discharge from AMI.

Stability over time of immature platelet fraction and comparison between EDTA and citrated whole blood samples

BACKGROUND

Immature platelets (IP) are the youngest circulating platelets, released from megakaryocytes, and demonstrating increased dimensions, significant RNA content, and enhanced activity. Immature platelet research focuses on a differential diagnostic help in patients with thrombocytopenia. The objectives of this study were to compare the variability of IP in citrate and EDTA samples, and to determine stability over time.

METHODS

Fifty-six patients were included for comparison between EDTA and citrate whole blood sample collection. Among the patients, 28 had thrombocytopenia (platelet count < 150G/L). Platelet measurement impedancemetry and fluorimetry were performed with Sysmex XN-9000. The immature platelet fraction (IPF) and absolute immature platelet count (A-IPC) were determined with a fluorescent method.

RESULTS

The mean value of platelet count with fluorescence was, in EDTA sample, 215 ± 171 and, in citrate sample, 153 ± 118 G/L. No significant difference was observed between IPF between EDTA and citrate (7.74 ± 6.68% vs. 8.45 ± 7.37%, p = 0.69), respectively. With the Bland-Altman analysis, the mean difference in the EDTA sample, between 1 and 24 h, was 8.06 ± 6.96% and 8.73 ± 7.12% for IPF, whereas in the citrate sample, between 1 and 6 h, it was 8.60 ± 7.29% and 7.54 ± 6.97%, for IPF. Comparing 1 h EDTA sample with 6 h citrate sample, the variance ratio was 0.974 (95% CI: 0.864-1.084) in IPF.

CONCLUSIONS

We confirmed the potential to conduct IP measurements up to 24 h in the EDTA sample and IPF measurements in the citrate sample for up to 6 h. These results may be useful for the use of IPF, which is a promising parameter whose interest in clinical practice and standardization is not yet well defined.

Routine and Advanced Laboratory Tests for Hemostasis Disorders in COVID-19 Patients: A Prospective Cohort Study

BACKGROUND

Thrombosis is frequent during COVID-19 disease, and thus, identifying predictive factors of hemostasis associated with a poor prognosis is of interest. The objective was to explore coagulation disorders as early predictors of worsening critical conditions in the intensive care unit (ICU) using routine and more advanced explorations.

MATERIALS

Blood samples within 24 h of ICU admission for viscoelastic point-of-care testing, (VET), advanced laboratory tests: absolute immature platelet count (A-IPC), von Willebrand-GPIb activity (vWF-GpIb), prothrombin fragments 1 + 2 (F1 + 2), and the thrombin generation assay (TGA) were used. An association with worse outcomes was explored using univariable and multivariable analyses. Worsening was defined as death or the need for organ support.

RESULTS

An amount of 85 patients with 33 in critical condition were included. A-IPC were lower in worsening patients (9.6 [6.4-12.5] vs. 12.3 [8.3-20.7], p = 0.02) while fibrinogen (6.9 [6.1-7.7] vs. 6.2 [5.4-6.9], p = 0.03), vWF-GpIb (286 [265-389] vs. 268 [216-326], p = 0.03) and F1 + 2 (226 [151-578] vs. 155 [129-248], p = 0.01) were higher. There was no difference observed for D-dimer, TGA or VET. SAPS-II and A-IPC were independently associated with worsening (OR = 1.11 [1.06-1.17] and OR = 0.47 [0.25-0.76] respectively). The association of a SAPS-II ≥ 33 and an A-IPC ≤ 12.6 G/L predicted the worsening of patients (sensitivity 58%, specificity 89%).

CONCLUSIONS

Immature platelets are early predictors of worsening in severe COVID-19 patients, suggesting a key role of thrombopoiesis in the adaption of an organism to SARS-CoV-2 infection.