Intravenous iron treatment reduces coagulability in patients with iron deficiency anaemia: a longitudinal study

Traumatic bleeding and mortality in mice are intensified by iron deficiency anemia and can be rescued with tranexamic acid

Background

Clinical evidence suggests that anemia exacerbates traumatic bleeding and worsens outcomes.

Objectives

To study the influence of iron deficiency anemia on traumatic bleeding, coagulopathy, and mortality.

Methods

C57BL/6J mice received an iron-deficient diet (8 weeks; ±1 mg intraperitoneal iron dextran 2 weeks before trauma). Control mice received a normal diet. Iron deficiency anemia was confirmed by hematocrit, red cell indices, and liver iron. Mice received saline or tranexamic acid (TXA; 10 mg/kg) just before liver laceration. Blood loss, coagulopathy (activated partial thromboplastin time, factor [F]II, FV, FVIII, FX, and fibrinogen), D-dimer, thrombin-antithrombin complexes, and plasmin-alpha-2-antiplasmin complexes were analyzed at 15 and 60 minutes, and a cytokine panel was performed at 60 minutes and 6 hours after trauma. Survival was monitored for 7 days.

Results

Compared with nonanemic mice, anemic mice had lower hematocrit and hepatic iron content. Anemic mice experienced higher blood loss compared with nonanemic mice, which was reduced by TXA. Both groups developed traumatic coagulopathy characterized by activated partial thromboplastin time prolongation, thrombin-antithrombin complex formation, and depletion of FV, FVIII, and fibrinogen. TXA corrected the coagulopathy. However, plasmin-alpha-2-antiplasmin complex formation and D-dimers, markers of fibrinolysis, were higher in anemic mice and were not corrected by TXA. Seven-day survival was low in anemic mice, and rescued by TXA, but high in nonanemic mice without additional improvement by TXA. Among cytokines, only interleukin-6 increased, which was prevented by TXA most notably in anemic mice.

Conclusion

These observations provide first and critical proof-of-principle evidence that anemia accelerates traumatic bleeding and increases mortality, which could be rescued by anemia correction (parenteral iron) or periprocedural TXA.

Thrombin generation assay in platelet-poor plasma in children with iron deficiency anemia

OBJECTIVES

Iron deficiency anemia (IDA) is the most common type of anemia in childhood and it leads to a hypercoagulable state. We investigated endogenous thrombin production in platelet-poor plasma before and after oral iron replacement in children with IDA using the thrombin generation assay (TGA).

METHODS

A total of 72 children diagnosed with IDA (IDA group) and 60 healthy children (control group) were included in the study. Blood samples were collected from the patients before and 1 month after oral iron replacement. TGA parameters [lag time, time to peak, peak height, endogenous thrombin potential (ETP)] were studied.

RESULTS

In the IDA group, the lag time and time to peak decreased by 8.3% and 10.6%, respectively, and the endogenous thrombin potential (ETP) and peak height both increased by 30% compared to those of the control group. Compared to the values before iron replacement, 1 month after iron replacement, the lag time and time to peak increased by 8.7% and 5%, respectively, and the ETP and peak height decreased by 31% and 31.3%, respectively, and became similar to those of the control group.

CONCLUSION

Children with IDA have increased endogenous thrombin production in platelet-poor plasma and a tendency for hypercoagulability. These changes are reversible, and the ETP values become similar to those of healthy children 1 month after iron replacement.

Acute aortic intraluminal thrombus with embolisation and lower-limb ischaemia following intravenous iron sucrose infusion reaction

A woman in her 50s developed iron deficiency anaemia. Her medical history included hypertension, asthma and remote postpartum pulmonary embolism. There was a strong family history of atherosclerosis. After receiving intravenous iron sucrose (500 mg), she developed vomiting and large-volume diarrhoea, followed by diaphoresis, back pain, haemoconcentration (haematocrit increase, 0.242 to 0.326), leucocytosis and platelet count decline. Myocardial infarction was ruled out and the truncal pain subsided. However, 2 days postdischarge, she was diagnosed with aortic intraluminal thrombus (ILT) with embolisation into the lower extremities. The limbs were salvaged by emergency embolectomies and fasciotomies. Acute aortic ILT is a rare disorder that has not been previously reported as a complication of parenteral iron therapy. We postulate that acute intravascular volume losses (vomiting and diarrhoea) with resulting haemoconcentration and catecholamine-associated platelet activation and consumption, in a patient with subclinical aortic atherosclerosis, triggered acute aortic ILT presenting as lower-limb ischaemia.

Anemia-Associated Platelets and Plasma Prothrombin Time Increase in Patients with Adenomyosis

Patients with adenomyosis are hypercoagulable and often accompanied by anemia, but the specific changes in anemia-related coagulation parameters are still unclear. This study investigated the changes in and influencing factors of coagulation parameters related to anemia in patients with adenomyosis (AM). The coagulation parameters, including platelet count (PC), plasma prothrombin time (PT), activated partial prothrombin time (APTT), thrombin time (TT) and fibrinogen (FB), and hemoglobin (Hb), were measured in patients with adenomyosis (229 cases in AM group), uterine leiomyoma (265 cases in LM group), and undergoing tubal anastomosis (142 cases in the control group). The age of the control group was younger than that of the AM group and the LM group. Compared with the AM and LM groups, the uterus size of the control group was smaller; the AM group was larger than the LM group. The Hb concentration of the AM group was lower than that of the LM and control groups. Compared with the LM and control groups, PC increased and TT shortened in the AM group. APTT in the AM group was shorter than in the control group, and PT was longer than in the LM group. After adjustment using multiple logistic regression analysis, adenomyosis was correlated with Hb concentration (or = 0.971, 95% CI 0.954−0.988, p < 0.001), PC (or = 1.006, 95% CI 1.002−1.011, p = 0.004), PT (or = 3.878, 95% CI 2.347−6.409, p < 0.001), age (or = 1.062, 95% CI 1.013−1.114, p = 0.013), and uterine size (or = 1.103, 95% CI 1.011−1.203, p = 0.028). Correlation analysis showed that PC (r = −0.309) and PT (r = −0.252) were negatively correlated with anemia. The increase in Hb-related PC and PT in patients with adenomyosis indicates that the timely and early detection of coagulation parameters is needed for patients with severe anemia, older age, and larger uterine volume.

Platelet reactivity and platelet count in women with iron deficiency treated with intravenous iron

Background

Iron deficiency anemia (IDA) and heavy menstrual bleeding are prevalent, interrelated issues impacting over 300 million premenopausal women worldwide. IDA is generally associated with increased platelet counts; however, the effects of IDA and its correction on platelet function in premenopausal women remain unknown.

Objectives

We sought to determine how IDA and intravenous iron affect platelet count and platelet function in premenopausal women.

Methods

Hematologic indices were assessed in a multicenter, retrospective cohort of 231 women repleted with intravenous iron. Pre- and postinfusion blood samples were then obtained from a prospective cohort of 13 women to analyze the effect of intravenous iron on hematologic parameters as well as platelet function with flow cytometry and platelet aggregation assays under physiologic shear.

Results

Following iron replacement, anemia improved, and mean platelet counts decreased by 26.5 and 16.0 K/mm3 in the retrospective and prospective cohorts, respectively. Replacement reduced baseline platelet surface P-selectin levels while enhancing platelet secretory responses to agonists, including collagen-related peptide and ADP. Platelet adhesion and aggregation on collagen under physiologic shear also significantly increased following repletion.

Conclusion

We find that intravenous iron improves anemia while restoring platelet counts and platelet secretory responses in premenopausal women with iron deficiency. Our results suggest that iron deficiency as well as iron replacement can have a range of effects on platelet production and function. Consequently, platelet reactivity profiles should be further examined in women and other groups with IDA where replacement offers a promising means to improve anemia as well as quality of life.

Risk stratification and management of women with cardiomyopathy/heart failure planning pregnancy or presenting during/after pregnancy: a position statement from the Heart Failure Association of the European Society of Cardiology Study Group on Peripartum Cardiomyopathy

This position paper focusses on the pathophysiology, diagnosis and management of women diagnosed with a cardiomyopathy, or at risk of heart failure (HF), who are planning to conceive or present with (de novo or previously unknown) HF during or after pregnancy. This includes the heterogeneous group of heart muscle diseases such as hypertrophic, dilated, arrhythmogenic right ventricular and non-classified cardiomyopathies, left ventricular non-compaction, peripartum cardiomyopathy, Takotsubo syndrome, adult congenital heart disease with HF, and patients with right HF. Also, patients with a history of chemo-/radiotherapy for cancer or haematological malignancies need specific pre-, during and post-pregnancy assessment and counselling. We summarize the current knowledge about pathophysiological mechanisms, including gene mutations, clinical presentation, diagnosis, and medical and device management, as well as risk stratification. Women with a known diagnosis of a cardiomyopathy will often require continuation of drug therapy, which has the potential to exert negative effects on the foetus. This position paper assists in balancing benefits and detrimental effects.

Iron deficiency-induced thrombocytosis increases thrombotic tendency in rats

Iron deficiency (ID) is globally prevalent, and apart from anemia is associated with thrombocytosis. While considered benign, studies linking thrombotic events with prior ID anemia suggest otherwise. In this study we used animal models to assess the influence of ID on thrombotic tendency. Sprague-Dawley rats were fed control or iron-deficient diets and ferric carboxymaltose was used to reverse ID. Thrombosis was induced by stenosis of the inferior vena cava or damage to the right carotid artery using ferric chloride. Thrombi were evaluated histologically and by high frequency ultrasound in the venous model. ID consistently induced thrombocytosis alongside anemia. The growth of venous thrombi and the final dimensions of both arterial and venous thrombi were greater in animals with ID. In both models, platelet numbers correlated with the final thrombus size, with thrombi in iron-deficient animals having the largest platelet areas. Platelet function was also evaluated in surgically-naïve rats. Coagulability, determined by thromboelasto - graphy, and hemostasis, evaluated by tail transection, were enhanced in the animals with ID. Platelet P-selectin expression and plasma P-selectin levels were both higher in animals with ID. Platelet adhesion and aggregation in ID was impaired under shear flow but was intact in static assays. Iron replacement therapy reversed all ID-related changes in hematologic parameters, thrombus dimensions, and platelet assays. In summary, ID alone increases thrombotic tendency. Iron replacement therapy reverses these changes, making it a viable strategy for the prevention of ID-related thrombotic disease. This may be of importance in patients with chronic illnesses who may already be at increased risk of thrombosis, such as those with inflammatory bowel disease, chronic kidney disease, or cancer.