Complications of heparin administration in normal individuals

Effects of Bivalirudin and Unfractionated Heparin on Liver and Renal Function in Chinese Patients with Coronary Artery Disease Undergoing Coronary Angiography with/without Percutaneous Coronary Intervention

BACKGROUND AND AIMS

Unfractionated heparin (UFH) and bivalirudin are widely used as anticoagulants in cardiovascular medicine, including for thrombosis prevention during coronary angiography (CAG) and percutaneous coronary intervention (PCI). Little is known of the effects of UFH and bivalirudin on liver and kidney function in patients subjected to these procedures. This study compared the effects of bivalirudin and UFH on liver/renal function in patients with coronary artery disease who underwent CAG, with or without PCI.

METHODS

The study comprised 134 consecutive patients (40-89 years-old), who underwent CAG (or CAG and PCI); among them, 66 and 68 patients were subject to, respectively, bivalirudin or UFH. The following indicators of liver/renal function were measured before and after the procedures: plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen, estimated glomerular filtration rate (eGFR), creatinine clearance, and serum creatinine. Patients were further stratified by severity of chronic kidney disease (CKD), based on original eGFR.

RESULTS

Relative to baseline, in the bivalirudin group, ALT and AST were higher after CAG (p=0.005, 0.025), while blood urea nitrogen and serum creatinine were lower (p=0.049, <0.001). In the UFH group, ALT, AST, eGFR, and creatinine clearance were lower after CAG (p≤0.001, all). Patients given bivalirudin with moderate or severe CKD, but not those with mild CKD, gained significant improvement in kidney function.

CONCLUSIONS

Relative to UFH, bivalirudin may better safeguard the renal function of patients with coronary artery disease who undergo CAG, especially patients with moderate-to-severe renal insufficiency. UFH may cause less liver damage than bivalirudin.

Heparin-Induced Thrombocytopenia in Healthy Individuals with Continuous Heparin Infusion

The risk for developing heparin-induced thrombocytopenia in healthy individuals is thought to be low, but monitoring recommendations remain controversial. Therefore, a retrospective cohort study was conducted to identify the incidence of thrombocytopenic events in a healthy research population exposed and re-exposed to continuous intravenous (IV) unfractionated heparin. The Division of Sleep Medicine and the Centre for Clinical Investigations at Brigham and Women's Hospital, Boston, Massachusetts, United States, instituted a standardized platelet monitoring procedure for all research protocols that involved heparin to detect platelet count decreases. Protocol-related frequent blood sampling required use of continuous IV unfractionated heparin infusion (5,000 unit/L in 0.45% saline at 40 mL/h) to maintain line patency over extended periods of IV access. From the years 2009 to 2012, a total of 273 healthy volunteers enrolled in Sleep Medicine research protocols met study criteria as having been exposed and/or re-exposed to continuously infused intravenous heparin for at least 4 hours. The mean continuous heparin exposure time was 88 ± 82 SD hours with a total of 397 heparin exposure and re-exposure events. Platelet count measurements were obtained on 629 occasions, representing a range from 2 to 9 draws per participant. No platelet count decrease of more than 50% was detected. There were no detected adverse bleeding or thrombotic events. In this retrospective study of healthy volunteers involved in a rigorously applied inpatient platelet monitoring protocol, heparin exposure and re-exposure did not lower platelet concentration and, therefore, does not appear to be associated with increased risk of HIT in this population.

Transaminase Elevation in Patients Treated with Unfractionated Heparin or Low Molecular Weight Heparin for Venous Thromboembolism

The purpose of this study was to evaluate the in cidence of transaminase elevation in patients treated with un fractionated (UFH) or low molecular weight heparin (LMWH). Patients receiving UFH, nadroparin, or reviparin for venous thromboembolism and with normal baseline transaminase val ues were evaluated for serum transaminase levels 10-14 days after the start of heparin therapy or at the end of treatment. The incidence of high transaminase was 4.7% overall (95% CI, 2.2 to 7.3), while it was 2.9% (95% CI, 0.1 to 5.6) and 6.7% (95% CI, 2.5 to 11.0) with UFH and LMWH treated patients, respec tively. The difference was equal to -3.8% (95% CI, -8.9 to 1.2) and the common odds ratio was equal to 0.38 (95% CI, 0.12 to 1.16, p = .09). Nadroparin treated patients showed a 5.7% (95% CI, 1.3 to 10.2) incidence of high transaminase levels, while reviparin treated patients presented a 10.3% incidence (95% CI, -0.7 to 21.4). The comparison with UFH showed a mild trend in favor of UFH when compared with nadroparin, but not with reviparin. In conclusion, the incidence of trans aminase increase during heparin treatment for a venous throm boembolic event is equal to 3%, 6%, and 10% in UFH-, na droparin-, and reviparin-treated patients, respectively. LMWHs showed a slightly higher average incidences of hypertransami nasemia as compared with UFH. Differences did not reach statistical significance. Key Words: Unfractionated heparin— Low molecular weight heparin—Hypertransaminasemia.

The effects of heparins on the liver: application of mechanistic serum biomarkers in a randomized study in healthy volunteers

Heparins have been reported to cause elevations in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) but have not been associated with clinically significant liver injury. The mechanisms underlying these benign laboratory abnormalities are unknown. Forty-eight healthy men were randomized to receive subcutaneous injections of unfractionated heparin (UFH; 150 U/kg), enoxaparin sodium (1 mg/kg), dalteparin sodium (120 IU/kg), or adomiparin sodium (125 IU/kg; a novel heparin) every 12 h for 4.5 days. Asymptomatic elevations in serum ALT or AST were observed in >90% of the subjects. Elevations were also observed in the levels of serum sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), miR-122, high-mobility group box-1 protein (including the acetylated form), full-length keratin 18, and DNA. Keratin 18 fragments, which are apoptosis biomarkers, were not detected. Biomarker profiles did not differ significantly across heparin treatments. We conclude that heparins as a class cause self-limited and mild hepatocyte necrosis with secondary activation of an innate immune response.

Thrombin generation in mesalazine refractory ulcerative colitis and the influence of low molecular weight heparin

BACKGROUND

In ulcerative colitis (UC), a state of hypercoagulation has frequently been observed. Low molecular weight heparin (LMWH) has shown beneficial effects as an adjuvant treatment of steroid refractory UC in open trials. We assessed potential therapeutic effects of the LMWH reviparin in hospitalised patients with mesalazine refractory UC, as well as its influence on haemostasis factors.

METHODS

Twenty-nine patients with mild-to-moderately active UC were included in a double-blind placebo controlled trial. All patients had a flare-up of disease under mesalazine treatment. Reviparin (Clivarin) 3,436 IU anti-Xa/0.6 ml or placebo s.c. was added, and self-administered twice daily for 8 weeks. Patients were monitored for possible adverse events and changes in clinical symptoms. Endoscopical, histological, biochemical and haemostasis parameters were analysed.

RESULTS

Tolerability and compliance were excellent and no serious adverse events occurred. No significant differences were observed on the clinical, endoscopical and histological outcome, as compared to placebo. A high intrinsic and extrinsic thrombin potential was found before LMWH therapy. However, the significant reduction in the thrombin generation by LMWH was not related to the reduction in disease activity.

CONCLUSION

The LMWH reviparine reduces thrombin generation in patients with mild-to-moderately active, mesalazine refractory UC, but is not associated with a reduction in disease activity.

Two patients with heparin-induced thrombocytopenia followed by idiopathic (immune) thrombocytopenic purpura: case report

Heparin-induced thrombocytopenia (HIT) and idiopathic thrombocytopenic purpura (ITP) are separate and well-recognized clinical syndromes, 10both having potential for disastrous outcomes. Sequential occurrence of these two diseases has not been reported in the literature. We report herein two patients who were initially diagnosed as having HIT but whose later clinical course was similar to ITP. Although dysfunction of immune system seems to play a role, the precise mechanisms for the development of these diseases are unclear. As both conditions have different natural histories and require different treatment modalities, it is important to recognize that these two diseases may be seen sequentially.

Risk markers for thrombocytopenia in critically ill patients: a prospective analysis

STUDY OBJECTIVE

To identify independent risk markers for thrombocytopenia in critically ill patients.

DESIGN

Prospective, observational study.

SETTING

Eleven-bed intensive care unit-coronary care unit (ICU-CCU) in a community hospital.

PATIENTS

Three hundred sixty-two consecutive patients meeting inclusion criteria during 1 year.

INTERVENTION

Potential risk marker data were collected on admission to the ICU-CCU and for the period before development of thrombocytopenia (defined as two or more consecutive platelet counts < 150 x 10(3)/mm3 obtained at least 12 hours apart), or for the duration of ICU-CCU stay if thrombocytopenia did not develop.

MEASUREMENTS AND MAIN RESULTS

Thrombocytopenia developed in 68 patients (18.8%). Multivariate logistic regression analyses identified patients at risk on admission, but the predictive, potential of the regression model improved when all risk marker exposures during the ICU-CCU stay were considered. Independent risk markers included fresh frozen plasma administration, sepsis, musculoskeletal diagnosis, pulmonary artery catheter insertion, gastrointestinal diagnosis, packed red blood cell administration, and nonsurgical respiratory diagnosis. Higher admission platelet count and aspirin administration were associated with a lower risk of thrombocytopenia. Heparin administration was not identified as a risk marker, and no patient developed heparin-induced thrombocytopenia with thrombosis. Patients with thrombocytopenia had longer ICU-CCU and hospital stays, and higher ICU-CCU and hospital mortality than those without thrombocytopenia.

CONCLUSIONS

Development of thrombocytopenia in critically ill patients is associated with specific diagnoses, packed red cell and fresh frozen plasma transfusions, pulmonary artery catheter insertion, and admission platelet count.

Low molecular weight heparin treatment in steroid refractory ulcerative colitis: clinical outcome and influence on mucosal capillary thrombi

BACKGROUND

In ulcerative colitis, a state of hypercoagulation has frequently been observed. Unfractionated heparin has shown beneficial effects as an adjuvant treatment of steroid refractory ulcerative colitis in open trials and in one placebo-controlled trial. Low molecular weight heparin (LMWH) offers advantages in the method of administration, but it has not been evaluated in severe ulcerative colitis. We therefore assessed the tolerability, safety and potential therapeutical effects of LMWH in hospitalized patients with steroid refractory ulcerative colitis.

METHODS

Twenty-five patients with severely active ulcerative colitis were included in an open-labelled trial. All patients had a flare-up of disease under glucocorticosteroid treatment. Nadroparine calcium 5.700 IE anti-Xa/0.6 mL s.c. was self-administered twice daily for 8 weeks. Patients were monitored for possible adverse events, and changes in clinical symptoms and in laboratory, endoscopical and histological results were analysed.

RESULTS

Tolerability and compliance were excellent and no serious adverse events occurred. In 20 of 25 patients, a good clinical and laboratory response was observed. Also, the endoscopic and histological signs of inflammation were found to be significantly improved. However, this was not accompanied by a significant reduction in the number of mucosal microvascular thrombi after 8 weeks of LMWH treatment.

CONCLUSION

LMWH may be a safe adjuvant therapy for patients with active, glucocorticosteroid refractory ulcerative colitis.

Elevation of hepatic transaminases after enoxaparin use: case report and review of unfractionated and low-molecular-weight heparin-induced hepatotoxicity

Enoxaparin, a low-molecular-weight heparin (LMWH), is widely used for the treatment and prophylaxis of thromboembolic disorders, such as deep vein thrombosis. Low-molecular-weight heparin products have smaller and more uniform molecular weights than unfractionated heparin, allowing them to exhibit a much greater affinity for factor Xa than factor IIa. Compared with traditional unfractionated heparin, LMWHs have proved to be equally efficacious and may be safer. The distinctive characteristics of LMWHs have resulted in decreased rates of bleeding and equivalent rates of thrombocytopenia compared with unfractionated heparin. This favorable safety profile has been identified in several studies and may have led clinicians to believe that LMWHs have lower frequencies of all common side effects. A 66-year-old woman developed increased hepatic transaminases during treatment with enoxaparin for a deep vein thrombosis; they returned to normal after enoxaparin discontinuation. A causal relationship between unfractionated heparin and asymptomatic, transient increases in hepatic transaminase levels has been documented; these increased levels also appear to be an underrecognized, adverse effect of LMWH therapy.

Effects of aprosulate, a novel synthetic glycosaminoglycan, on coagulation and platelet function parameters: a prospective, randomized phase I study

In a phase I clinical trial the effect of the highly sulfated polyanion "Aprosulate" was studied in healthy volunteers using different coagulation and platelet function parameters. Eighteen healthy volunteers aged 21 to 30 years received two single subcutaneous doses of aprosulate (0.5 mg/kg body weight; 1.0 mg/kg body weight), or unfractionated heparin (Calciparin 7,500 IU). The washout period between the different drugs/doses was at least 7 days. Coagulation and platelet function parameters (activated partial thromboplastin time, Heptest, fibrinogen, von Willebrand factor, ristocetin cofactor, platelet adhesion to siliconized glass, and platelet-induced thrombin generation time [a new method for measuring thrombin generation in platelet-rich plasma in the presence of platelets]) were assessed during 24 hours after each injection. Aprosulate led to a significant and dose-dependent prolongation of activated partial thromboplastin time and Heptest. This effect lasted for 4 hours (activated partial thromboplastin time) to 8 hours (Heptest). Activated partial thromboplastin time was not prolonged after the injection of unfractionated heparin (7,500 IU). Fibrinogen, von Willebrand factor, and ristocetin cofactor remained unchanged with both drugs. Platelet induced thrombin generation time was slightly prolonged and platelet adhesion was slightly diminished up to 2 hours using 0.5 mg/kg aprosulate, and up to 4 hours using 1.0 mg/kg aprosulate while the platelet induced thrombin generation time system was not influenced by the subcutaneous injection (7,500 IU) of unfractionated heparin. Both drugs and doses were well tolerated. Plasma transaminase concentrations alanin aminotransferase and aspartate aminotransferase serum values were slightly increased in some volunteers but returned to normal during or after the study (< 4 weeks). Further clinical trials will have to establish whether aprosulate is an effective drug for the prophylaxis of deep venous thrombosis.

RD heparin compared with warfarin for prevention of venous thromboembolic disease following total hip or knee arthroplasty. RD Heparin Arthroplasty Group

The efficacy and safety of RD heparin, a low-molecular-weight heparin, for the prevention of venous thromboembolic disease among patients managed with an elective total hip or total knee arthroplasty were compared with the efficacy and safety of warfarin in an open-label prospective, multicenter trial. Patients were randomized to receive either a fixed dose of fifty anti-factor-Xa units of RD heparin per kilogram of body weight, administered subcutaneously twice daily, beginning postoperatively; a fixed dose of ninety anti-factor-Xa units of RD heparin per kilogram of body weight, administered subcutaneously once daily, beginning postoperatively; or five milligrams of warfarin, administered orally preoperatively, followed by a daily adjusted dose of warfarin to prolong the prothrombin time ratio to 1.2 to 1.5. The primary measure of efficacy was contrast venography of the treated limb, performed by local radiologists blinded to the type of treatment that had been assigned. Nine hundred and sixty-nine patients had a complete assessment for the presence of deep-vein thrombosis. The over-all rates of venous thromboembolic disease were 16 percent (95 pecent confidence interval, 13 to 21 percent) (fifty-three) for the 328 patients who received RD heparin twice daily, 21 percent (95 percent confidence interval, 17 to 26 percent) (sixty-eight) for the 320 patients who received RD heparin once daily, and 27 percent (95 percent confidence interval, 22 to 32 percent) (eighty-seven) for the 321 patients who received warfarin (p < 0.001 for RD heparin administered twice daily compared with warfarin; p = 0.13 for RD heparin administered once daily compared with warfarin). Compared with warfarin, RD heparin administered twice daily and RD heparin administered once daily reduced the risk of venous thromboembolic disease by 41 percent (95 percent confidence interval, 20 to 56 percent) and 18 percent (95 percent confidence interval, -6 to 37 percent), respectively. The rates of venous thromboembolic disease after 523 total hip arthroplasties were 8, 14, and 14 percent for the patients who received RD heparin twice daily, those who received it once daily, and those who received warfarin (p = 0.07 for RD heparin administered twice daily compared with warfarin; p = 0.82 for RD heparin administered once daily compared with warfarin).(ABSTRACT TRUNCATED AT 400 WORDS)

Phase I--study with aprosulate, a new synthetic anticoagulant

This paper describes the first human study with aprosulate, a new chemically synthesized anticoagulant with a defined molecular structure and a molecular weight of 2388. Twelve healthy male volunteers received subcutaneous injections of placebo on the first day followed by ascending doses of aprosulate in the range of 0.25 mg/kg to 2.0 mg/kg body weight on alternate days. Anticoagulant, pharmacokinetic and safety parameters were assessed for 48 hours after each injection. The activated partial thromboplastin time and the Heptest showed a dose-dependent increase for up to ten hours after each application. A trend towards prolongation of the bleeding time was indicated with higher doses. In general, the tolerance was good. Plasma transaminase concentrations were raised in some volunteers but returned spontaneously to normal during or after the study.

Heparin-associated thrombocytopenia: a critical review and pooled analysis

The purpose of this study is to determine the incidence of heparin-associated thrombocytopenia (HAT) for various subgroups of heparin exposed patients and the impact of study quality on the reported incidence. Articles were identified using a Medline search, a manual search of the Index Medicus, and a review of article references. Key data included heparin type, administration route, indication, treatment duration, outcome criteria, incidence, and platelet count reliability. The pooled incidence estimate in studies requiring a repeatedly abnormal platelet count was compared with estimates from studies not requiring a repeated platelet count. The results showed that there were no adequately designed studies to estimate the incidence of HAT-related thrombosis or hemorrhage. The pooled incidence of HAT in studies requiring a reproducibly lowered platelet count (< 100,000/microL) was 3/281 (1.1%) with intravenous porcine heparin and 4/140 (2.9%) with intravenous bovine heparin. This difference was not statistically significant. The incidence of HAT with intravenous bovine heparin was significantly lower in studies that required a repeated platelet count. The incidence of HAT with heparin administered subcutaneously was small (0%) and in those studies requiring a repeatedly abnormal platelet count, there was no difference between porcine and bovine heparin. The authors concluded that the incidence of HAT is < 3% with intravenous heparin and extremely low for subcutaneous heparin. Study quality may influence the reported incidence of HAT.

Pharmacodynamics, clinical indications, and adverse effects of heparin

Heparins are a heterogenous group of naturally occurring glycosaminoglycans characterized by anticoagulant activity and a wide range of molecular weights (low molecular weight or fractionated heparins evolving within the past two decades). Cofactors for endogenous inhibitors of coagulation (antithrombin III and heparin cofactor II), heparin administration results in a hypocoagulable state. Various platelet activities, including inhibition of activity induced by platelet-derived growth factors on vascular smooth muscle, also have been noted. Divorced of anticoagulant nature, novel applications may include a role in atherosclerosis prevention, acceleration of collateral coronary as well as peripheral circulation (i.e., angiogenesis), and continued (chronic) post-myocardial infarction therapy. Established indications include treatment of various thrombotic diseases, unstable angina, and thrombosis chemoprophylaxis in medical/surgical patients. The antithrombotic potential of the heparins is used also in thrombosis management related to extracorporeal circulatory assistance or dialysis devices. Heparin's therapeutic potential in the postphlebitic syndrome as well as in acute treatment of myocardial infarction (primarily and adjunctively with various thrombolytic agents) continues to undergo evaluation; however, early data review shows favorable trends for its inclusion in situations that favor thrombus generation (e.g., anterior myocardial infarction). Although associated with thrombocytopenia or hypertransaminasemia, the heparins are relatively well tolerated. In a small subset of patients, a severe thrombocytopenia may ensue, which generally resolves on medication withdrawal. As this class of glycosaminoglycans becomes better characterized, new indications may emerge for both native and the newer fractionated heparins.

Heparin-induced thrombocytopenia and thrombosis: reversal with streptokinase. A case report and review of literature

Heparin-induced thrombocytopenia and thrombosis is associated with a significant incidence of morbidity and mortality. Prompt recognition of this complication and immediate withdrawal of heparin therapy are imperative. This report describes a case of heparin-induced thrombosis and thrombocytopenia with major vascular insufficiency of the extremities. This is the first reported instance of the use of intravenous streptokinase for the treatment of heparin-induced venous thrombosis.

Hirudin in haemodialysis

The usability of recombinant hirudin as anticoagulant agent in haemodialysis was studied in nephrectomized dogs. To this end, we examined the capability of recombinant hirudin to penetrate the membranes of different capillary dialyzers used. Furthermore we investigated the pharmacokinetic behaviour of recombinant hirudin in nephrectomized dogs as well as its capability to prevent the activation of the clotting system and fibrin deposition during haemodialysis. The present results evidence the efficiency of recombinant hirudin in preventing thrombus formation in experimental haemodialysis and hence its suitability as anticoagulant in such extracorporeal circulation.

An evaluation of the biological response to Fraxiparine, (a low molecular weight heparin) in the healthy individual

The tolerance of a low molecular weight heparin (Fraxiparine, Choay, Paris, France) in normal individuals was determined using a two part investigation. Study 1 consisted of administering escalating doses of Fraxiparine in a single blinded, placebo controlled, rising dose tolerance evaluation. The daily doses tested were 3750 U AXA IC, 7500 U AXa IC, 11250 U AXa IC, 15000 U AXa IC, and 22500 U AXa IC Fraxiparine subcutaneously for 5 consecutive days. In study 2, we compared the tolerance of unfractionated heparin (UH) administered as 5000 IU every 8 hours, to that of 7500 U AXa IC/day or 15000 U AXa IC/day of Fraxiparine administered once daily. Our results indicated very good tolerance to this low molecular weight heparin (LMWH) at doses up to and including 22500 U AXa IC/day. We observed significantly elevated increases in transaminases following LMWH administration. In our second study we observed that the increase in serum transaminases seen after 15000 U AXa IC/day Fraxiparine was without significant difference from that observed following UH (5000 IU every 8 hours). AXa examination revealed an accumulation of AXa effect after 5 days of administration at doses greater than 15000 U AXa IC, and there was good correlation between AXa and APTT at Fraxiparine doses greater than 15000 U AXa IC/day. No thrombocytopenia was associated with Fraxiparine. We conclude that Fraxiparine is relatively well tolerated and shows accumulation after daily dosing with greater than 15000 U AXa IC.

Heparin-induced thrombocytopenia

There are two types of heparin-induced thrombocytopenia. Type I is more common, has an early onset, and is mild, transient, and benign. Type I is due to direct heparin-induced platelet aggregation and is rarely associated with thromboembolic sequela. Type II is infrequent, has a late onset, and is more severe. Type II is due to an immune-mediated platelet aggregation caused by IgG and IgM that becomes bound to platelets. In Type II, the antibody titers decline over several months; however, early reexposure can result in a catastrophic secondary immune response. Frequently, Type II is associated with life- or limb-threatening thromboembolic complications (white clots), including stroke.

Heparin-induced thrombocytopenia and thrombosis in ischemic stroke

We reviewed the records of all patients who underwent carotid endarterectomy at our institution during the period from January 1970 through December 1986 to determine the frequency of postoperative occlusions and the role of heparin-induced thrombosis in patients with such occlusions. After 2,527 carotid endarterectomies, a total of 19 occlusions occurred in 18 patients. Of these 18 patients, 6 had an associated heparin-induced coagulation disorder, 3 of whom are described in detail. Although heparin is a useful anticoagulant, it may precipitate occlusion of vessels after an endarterectomy procedure, either at the endarterectomy site or elsewhere. Physicians should be aware of the potentially increased risk for embolic or thrombotic cerebrovascular events in patients who receive heparin therapy.

Effect of heparin on platelet count and platelet aggregation

The in vitro effect of heparin on platelet aggregation was studied in three groups: in 26 subjects recently treated with heparin, in 18 subjects on maintenance hemodialysis, and in 20 normal controls. With the aid of Technicon H6000, platelet counts and platelet aggregations were compared in whole blood samples collected in ethylenediaminetetraacetic acid (EDTA) and in heparinized tubes. Although there was no significant difference between platelet count of heparinized and EDTA blood in the control group, the dialysis group and the group recently treated with heparin showed significantly lower platelet counts and more platelet aggregation in heparinized tubes than in EDTA tubes. We speculate that the majority of subjects exposed to heparin develop an antibody or a proaggregator which can aggregate or agglutinate platelets in the presence of heparin and causes destruction of platelets; but only in a small percentage of subjects receiving heparin is this reaction severe enough to cause thrombocytopenia.