Effect of anemia on coagulation and platelet function: a whole blood in vitro study

Preoperative laboratory parameters associated with deep vein thrombosis in patients with ovarian cancer: retrospective analysis of 3,147 patients in a single institute

OBJECTIVE

Patients with ovarian cancer have a high risk of developing thrombosis. We aimed to investigate laboratory parameters associated with deep vein thrombosis (DVT) in patients treated for ovarian cancer.

METHODS

We retrospectively analyzed pre-operation laboratory data of patients with ovarian cancer for DVT at the National Cancer Center, Korea, between January 2000 and February 2021. The test items were white blood cell count, absolute neutrophil count (ANC), hemoglobin, platelets, monocytes, serum glucose, CA125, D-dimer, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT), and body mass index (BMI). Differences between patients with and without DVT were compared with Wilcoxon rank-sum test. We analyzed the variables using logistic regression. Items with significant odds ratios were included in multivariate logistic regression. Significant variables were selected using backward elimination. Items were further categorized based on reference ranges. Univariate and multivariate analyses were performed to identify items with abnormal values associated with DVT.

RESULTS

From 3,147 patient samples analyzed, 286 (9.1%) patients with DVT were selected. Differences between patients with vs without DVT were statistically significant for hemoglobin, monocyte, serum glucose, CA125, PT, aPTT, fibrinogen, D-dimer, and BMI. After univariate and multivariate analysis, monocyte, glucose, and PT remained significant. Among the categorical variables, low hemoglobin, high monocyte, high CA125, prolonged PT, and high BMI remained significant after univariate and multivariate analysis.

CONCLUSION

Pre-operation laboratory data of low hemoglobin, high monocyte percentage, high serum glucose, high CA125, prolonged PT, and high BMI were associated with DVT.

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial

Background

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST.

Methods

The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo].

Results

Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST.

Conclusion

The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST.

Clinical Trial Registration

http://www.clinicaltrials.gov, identifier NCT00809965.

Impact of transfusion strategy on platelet aggregation and biomarkers in myocardial infarction patients with anemia

BACKGROUND

Higher rates of thrombotic events have been reported in myocardial infarction (MI) patients requiring blood transfusion. The impact of blood transfusion strategy on thrombosis and inflammation is still unknown.

OBJECTIVE

To compare the impact of a liberal vs. a restrictive transfusion strategy on P2Y12 platelet reactivity and biomarkers in the multicentric randomized REALITY trial.

METHODS

Patients randomized to a liberal (hemoglobin ≤10 g/dL) or a restrictive (hemoglobin ≤8 g/dL) transfusion strategy had VASP-PRI platelet reactivity measured centrally in a blinded fashion and platelet reactivity unit (PRU) measured locally using encrypted VerifyNow; at baseline and after randomization. Biomarkers of thrombosis (P-selectin, PAI-1, vWF) and inflammation (TNF-α) were also measured. The primary endpoint was the change in the VASP-PRI (difference from baseline and post randomization) between the randomized groups.

RESULTS

A total of 100 patients randomized were included in this study (n = 50 in each group). Transfused patients received on average 2.4 ± 1.6 units of blood. We found no differences in change of the VASP PRI (difference 1.2% 95% CI (-10.3-12.7%)) or by the PRU (difference 13.0 95% CI (-21.8-47.8)) before and after randomization in both randomized groups. Similar results were found in transfused patients (n = 71) regardless of the randomized group, VASP PRI (difference 1.7%; 95% CI (-9.5-1.7%)) or PRU (difference 27.0; 95% CI (-45.0-0.0)). We did not find an impact of transfusion strategy or transfusion itself in the levels of P-selectin, PAI-1, vWF, and TNF-α.

CONCLUSION

In this study, we found no impact of a liberal vs. a restrictive transfusion strategy on platelet reactivity and biomarkers in MI patients with anemia. A conclusion that should be tempered due to missing patients with exploitable biological data that has affected our power to show a difference.

Relationship between anaemia, coagulation parameters during pregnancy and postpartum haemorrhage at childbirth: a prospective cohort study

OBJECTIVES

To investigate the association between coagulation parameters and severity of anaemia (moderate anaemia: haemoglobin (Hb) 7-9.9 g/dL and severe anaemia: Hb <7 g/dL) during pregnancy and relate these to postpartum haemorrhage (PPH) at childbirth.

DESIGN

A prospective cohort study of pregnant women recruited in the third trimester and followed-up after childbirth.

SETTING

Ten hospitals across four states in India.

PARTICIPANTS

1342 pregnant women.

INTERVENTION

Not applicable.

METHODS

Hb and coagulation parameters: fibrinogen, D-dimer, D-dimer/fibrinogen ratio, platelets and international normalised ratio (INR) were measured at baseline. Participants were followed-up to measure blood loss within 2 hours after childbirth and PPH was defined based on blood loss and clinical assessment. Associations between coagulation parameters, Hb, anaemia and PPH were examined using multivariable logistic regression models.

OUTCOMES MEASURES

Adjusted OR with 95% CI.

RESULTS

In women with severe anaemia during the third trimester, the D-dimer was 27% higher, mean fibrinogen 117 mg/dL lower, D-dimer/fibrinogen ratio 69% higher and INR 12% higher compared with women with no/mild anaemia. Mean platelets in severe anaemia was 37.8×109/L lower compared with women with moderate anaemia. Similar relationships with smaller effect sizes were identified for women with moderate anaemia compared with women with no/mild anaemia. Low Hb and high INR at third trimester of pregnancy independently increased the odds of PPH at childbirth, but the other coagulation parameters were not found to be significantly associated with PPH.

CONCLUSION

Altered blood coagulation profile in pregnant women with severe anaemia could be a risk factor for PPH and requires further evaluation.

Severity of Anaemia Has Corresponding Effects on Coagulation Parameters of Sickle Cell Disease Patients

Sickle cell disease (SCD) is an inherited condition characterized by chronic haemolytic anaemia. SCD is associated with moderate to severe anaemia, hypercoagulable state and inconsistent platelet count and function. However, studies have yielded conflicting results with regards to the effect of anaemia on coagulation in SCD. The purpose of this study was to determine the effect of anaemia severity on selected coagulation parameters of SCD patients. Four millilitres of venous blood samples were taken from the participants (SCD and non-SCD patients) and used for analysis of full blood count and coagulation parameters. Data was analysed using SPSS version-16. From the results, it was seen that individuals with SCD had a prolonged mean PT, APTT and high platelet count compared to the controls. There was also significant difference in the mean PT (p = 0.039), APTT (p = 0.041) and platelet count (p = 0.010) in HbSS participants with severe anaemia. Mean APTT also showed significant difference (p = 0.044) with severe anaemia in HbSC participants. It can be concluded that SCD patients have prolonged PT, APTT and increased platelet count which might predispose them to bleeding episodes and thrombocytosis. Significant difference was also seen between severity of anaemia and mean PT, APTT and platelet count in HbSS individuals.