Assessment of Trends in Guideline-Based Oral Anticoagulant Prescription for Patients With Ischemic Stroke and Atrial Fibrillation in China.

Importance: Adherence to oral anticoagulants (OACs) per guideline recommendations is crucial in reducing ischemic stroke and systemic thromboembolism in high-risk patients with ischemic stroke and atrial fibrillation. However, data on OAC use are underreported in China. Objective: To assess adherence to the Chinese Stroke Association or the American Heart Association/American Stroke Association's clinical management guideline-recommended prescription of OACs, the temporal improvement in adherence, and the risk factors associated with OAC prescriptions. Design, Setting, and Participants: This quality improvement study was conducted at 1430 participating hospitals in the Chinese Stroke Center Alliance (CSCA) among patients with ischemic stroke and atrial fibrillation enrolled in the CSCA between August 1, 2015, and July 31, 2019. Exposure: Calendar year. Main Outcomes and Measures: Adherence to the Chinese Stroke Association or the American Heart Association/American Stroke Association's clinical management guideline-recommended prescribing of OACs (warfarin and non-vitamin K OACs, including dabigatran, rivaroxaban, apixaban, and edoxaban) at discharge. Results: Among 35 767 patients (18 785 women [52.5%]; mean [SD] age, 75.5 [9.2] years) with previous atrial fibrillation at admission, the median CHA2DS2-VASc (cardiac failure or dysfunction, hypertension, age 65-74 [1 point] or ≥75 years [2 points], diabetes, and stroke, transient ischemic attack or thromboembolism [2 points]-vascular disease, and sex category [female]) score was 4.0 (interquartile range, 3.0-5.0); 6303 (17.6%) were taking OACs prior to hospitalization for stroke, a rate that increased from 14.3% (20 of 140) in the third quarter of 2015 to 21.1% (118 of 560) in the third quarter of 2019 (P < .001 for trend). Of 49 531 eligible patients (26 028 men [52.5%]; mean [SD] age, 73.4 [10.4] years), 20 390 (41.2%) had an OAC prescription at discharge, an increase from 23.2% (36 of 155) in the third quarter of 2015 to 47.1% (403 of 856) in the third quarter of 2019 (P < .001 for trend). Warfarin was the most commonly prescribed OAC (11 956 [24.2%]) and had the largest temporal increase (from 5.8% [9 of 155] to 20.7% [177 of 856]). Older age (adjusted odds ratio [aOR] per 5 year increase, 0.89;95% CI, 0.89-0.90), lower levels of education (aOR for below elementary school, 0.84; 95% CI, 0.74-0.95 ), lower income (aOR for ≤¥1000 [$154], 0.66; 95% CI, 0.59-0.73), having new rural cooperative medical scheme insurance (aOR, 0.92; 95% CI, 0.87-0.96), prior antiplatelet use (aOR, 0.70; 95% CI, 0.66-0.74), having several cardiovascular comorbid conditions (including stroke or transient ischemic attack [aOR, 0.78; 95% CI, 0.75-0.82], hypertension [aOR, 0.84; 95% CI, 0.80-0.89], diabetes [aOR, 0.91; 95% CI, 0.83-0.99], dyslipidemia [aOR, 0.87; 95% CI, 0.80-0.94], carotid stenosis [aOR, 0.83; 95% CI, 0.69-0.98], and peripheral vascular disease [aOR, 0.80; 95% CI, 0.71-0.90]), and admission to secondary hospitals (aOR, 0.71; 95% CI, 0.68-0.74) or hospitals located in the central region of China (aOR, 0.80; 95% CI, 0.75-0.84) were associated with not being prescribed an OAC at discharge. Conclusions and Relevance: This quality improvement study suggests that, despite significant improvement over time, OAC prescriptions remained low. Efforts to increase OAC prescriptions, especially non-vitamin K OACs, are needed for vulnerable subgroups by age, socioeconomic status, and presence of comorbid conditions.

Prophylaxis of venous thromboembolism in general surgery in Spain. Analysis of a national survey. / Profilaxis del tromboembolismo venoso en cirugía general en España. Análisis de una encuesta nacional.

INTRODUCTION: Venous thromboembolism (VTE) represents a serious postoperative complication that can be prevented by adequate thromboprophylaxis. Surveys provide relevant information about clinician's attitudes and preferences regarding VTE prophylaxis. METHODS: Transversal, descriptive study based on a survey sent to general surgeons members of the Spanish Association of Surgeons (AEC), that included 31 questions regarding postoperative VTE and its prevention, as well as three clinical scenarios. RESULTS: 530 surgeons, 21.8% of the 2,429 invited by electronic mail to participate, completed the survey. Most of the answering clinicians work on in big teaching hospitals, and 28.5% are residents. VTE represents a serious problem for 28% of participants. Although 81% consider that their knowledge on the prevention of postoperative VTE is adequate, a similar percentage recognizes the need for further education. The vast majority (98.7%) use low molecular weight heparins, which are considered the most effective and safe modality, followed by mechanical methods. The Caprini risk assessment score is used by 81% of surgeons, who usually start pharmacological prophylaxis preoperatively. However, there are remarkable differences in the dosing of heparins, timing of initiation, and duration, especially in non-oncologic surgical patients. CONCLUSIONS: Most Spanish surgeons are interested in the prevention of postoperative VTE. Overall, the level of knowledge on thromboprophylaxis is adequate. However, our results indicate that there is a need for better education on relevant practical aspects of prophylaxis that could be achieved by incorporating recommendations from recent guidelines to local hospital-based protocols.

Peer-Review Competency Assessment Engages Staff and Influences Patient Outcomes.

BACKGROUND: Nurse educators must guide competency assessment in a way that influences safe patient care. The goal of this innovative competency assessment was for RNs to demonstrate performance of sound practice related to anticoagulation medication, pressure injuries, and pain management using a peer-review format. METHOD: The process was initiated through the unit-based team. The clinical RN was required to bring forth the information that he or she had met the competency requirements. Rubrics provided consistency in evaluation. RESULTS: The process was perceived to have evaluated actual performance and allowed demonstration of performance. For patient outcomes, anticoagulation safety measures were sustained, pressure injury measures were improved, and pain outcome measures were not improved during and after the competency period. CONCLUSION: A peer-review process for clinical RN competency assessment enhanced professionalism through professional practice evaluation, was perceived as favorable, and was associated with positive patient outcomes. J Contin Educ Nurs. 2018;49(3):119-126.

Assessment of Outcomes of Treatment With Oral Anticoagulants in Patients With Atrial Fibrillation and Multiple Chronic Conditions: A Comparative Effectiveness Analysis.

Importance: Comparative effectiveness and safety of oral anticoagulants in patients with atrial fibrillation (AF) and multiple chronic conditions (MCC) are unknown. Objective: To determine whether there are differences in efficacy and safety of dabigatran, rivaroxaban, and warfarin regarding stroke prevention and bleeding rates, respectively, in elderly patients with AF with MCC. Design, Setting, and Participants: This retrospective comparative effectiveness analysis included data from the population-based Medicare beneficiaries database, evaluating patients with new AF diagnosed from January 1, 2010, to December 31, 2013, who initiated an oral anticoagulant within 90 days of diagnosis. Patients with CHA2DS2-VASc scores of 1 to 3, 4 to 5, and 6 or higher; HAS-BLED scores of 0 to 1, 2, and 3 or higher; and Gagne comorbidity scores of 0 to 2, 3 to 4, and 5 or higher were categorized as having low, moderate, or high morbidity, respectively. Within morbidity categories, patients receiving dabigatran, rivaroxaban, or warfarin were matched using a 3-way propensity matching, and the relative hazards of stroke, major hemorrhage (MH), and death were evaluated. Data analysis included follow-up from the date of initial anticoagulant use through December 31, 2013. Exposures: Rivaroxaban (20 mg once daily), dabigatran (150 mg twice daily), or warfarin therapy. Main Outcomes and Measures: Ischemic stroke, MH, and death. Results: The study cohort included 21 979 patients using dabigatran (mean [SD] age, 75.8 [6.4] years; 51.1% female), 23 177 using rivaroxaban (mean [SD] age, 75.8 [6.4] years; 49.9% female), and 101 715 using warfarin (mean [SD] age, 78.5 [7.2] years; 57.3% female). In the propensity-matched cohorts, there were no differences in stroke rates between the 3 oral anticoagulant groups. Dabigatran users had lower hazard of MH compared with warfarin users among patients with low MCC (hazard ratio [HR], 0.62; 95% CI, 0.47-0.83; P < .001; for MCC defined as low CHA2DS2-VASc score), and similar risk in patients with moderate to high MCC. While there was no difference in MH between rivaroxaban and warfarin users, rivaroxaban users had significantly higher MH risk compared with dabigatran users in the medium and high comorbidity groups (HR, 1.24; 95% CI, 1.04-1.48; P = .02 and HR, 1.28; 95% CI, 1.05-1.56; P = .01, respectively). Dabigatran and rivaroxaban users had lower rates of death compared with warfarin users (HR ranged from 0.52-0.84), across comorbidity levels. Conclusions and Relevance: Oral anticoagulants are similarly effective in stroke prevention among patients with AF with MCC. However, dabigatran and rivaroxaban use may be associated with lower rates of mortality in patients with MCC.

The Prophylaxis of Venous Thromboembolism.

BACKGROUND: Venous thromboembolism (VTE) is the third most common cardiovascular condition, after myocardial infarction and stroke. Prophylactic measures in accordance with current guidelines can significantly reduce the risk of VTE and the associated morbidity and mortality. Until now, the German interdisciplinary, evidence- and consensus-based (S3) clinical practice guideline on VTE prophylaxis was based on a complete review of all pertinent literature available in MEDLINE up to January 2008. More recent publications and drug approvals have made a thorough revision necessary. METHODS: A systematic search was carried out in the MEDLINE and Embase databases for publications that appeared from 1 January 2008 to 7 August 2013. Updates of 5 national and international reference guidelines and 2 new Health Technology Assessment (HTA) reports were considered as well. A structured consensus-finding process was carried out with delegates from 27 scientific medical societies and from the Union of Medical Specialist Associations. RESULTS: 46 randomized controlled trials (RCTs) were included for critical appraisal. New findings led to re-evaluation of the value of compression stockings in combination with pharmacological prophylaxis (open recommendation), and suggest equal value of non-vitamin K antagonist oral anticoagulants (NOACs) and low molecular weight heparins (LMWH) or fondaparinux in elective hip and knee replacement (strong recommendation). For patients undergoing hip fracture surgery, we recommend LMWH or fondaparinux. CONCLUSION: Further research is needed to assess the value of NOACs for pharmacological prophylaxis in orthopedic/trauma patients undergoing surgical procedures other than the ones mentioned above, and into the benefit and harm of new devices available for mechanical prophylaxis. The stringent implementation of basic measures such as early mobilization, movement exercises, and patient instruction is a key point to prevent venous thrombo - embolism.

Impact on Outcomes of Changing Treatment Guideline Recommendations for Stroke Prevention in Atrial Fibrillation: A Nationwide Cohort Study.

OBJECTIVE: To investigate the impact on outcomes of changing treatment guideline recommendations by comparing the proportion of patients with atrial fibrillation (AF) recommended oral anticoagulants (OACs) under the 2011 and 2014 American College of Cardiology/American Heart Association (ACC/AHA) guidelines. PATIENTS AND METHODS: We used the "National Health Insurance Research Database" in Taiwan, which included 354,649 patients with AF from January 1, 1996 through December 31, 2011. Patients with a CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score of 2 or more and a CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female sex category) score of 2 or more were considered to have a definitive indication for receiving OACs according to the 2011 and 2014 ACC/AHA guidelines, respectively. RESULTS: The percentages of patients with AF recommended OACs increased from 69.3% (n=245,598) under the 2011 guideline to 86.7% (n=307,640) under the new 2014 guidelines, an increment of 17.5% (95% CI, 17.4-17.6). Most women with AF (94.1%) and patients older than 65 years (97.2%) would receive OACs on the basis of the 2014 guidelines. Among patients previously not being recommended OACs in older guidelines, OAC use under the new guidelines was associated with a lower risk of adverse outcomes (ischemic stroke or intracranial hemorrhage or bleeding requiring blood transfusion or mortality) with an adjusted hazard ratio of 0.89 (95% CI, 0.85-0.94). CONCLUSION: In this nationwide cohort study, use of the 2014 guidelines led more patients with AF to receive OACs for stroke prevention, and this increased OAC use was associated with better outcomes. Better efforts to implement guidelines would lead to improved outcomes for patients with AF.

Recent guidelines and recommendations for laboratory assessment of the direct oral anticoagulants (DOACs): is there consensus?

A new generation of antithrombotic agents, which are conventionally known as direct oral anticoagulants (DOACs), have recently emerged and are continuing to be developed. These provide direct inhibition of either thrombin (factor IIa; FIIa) or activated factor X (FXa) and currently include dabigatran (FIIa inhibitor) and rivaroxaban, apixaban, and edoxaban (FXa inhibitors). The dogma that DOACs do not require laboratory monitoring is countered by ongoing recognition that laboratory testing for drug effects is needed in many situations. In this review, we summarize the background to establishment of DOACs, assess which tests were found to be useful to screen for or quantitate drug effects/levels, and then review published guidelines/recommendations to assess concordance. In brief, (a) for the anti-FIIa agent dabigatran, the recommended screening assays are activated partial thromboplastin time (APTT) and/or thrombin time (TT), and the quantitative assays (using a dabigatran standard) are dilute TT/direct thrombin inhibitor assay (Hemoclot thrombin inhibitor) or an ecarin-based assay such as the ecarin clot time (ECT); (b) for the anti-FXa agent rivaroxaban, the recommended screening assay is the prothrombin time (PT), but this was not endorsed by all guidelines, and the quantitative assay (using a specific rivaroxaban standard) is an anti-FXa assay; (c) for the anti-FXa agent apixaban, the general insensitivity of PT and APTT prevented most groups from providing recommendation, and instead there was generalized support for direct quantitative assessment using anti-FXa assays and specific apixaban standard; (d) there is insufficient data for other direct anti-FXa agents and limited guidance in the literature.

Consideration of international generic distribution policies on patient outcomes in the United States and Germany.

Generic substitution of narrow therapeutic index drugs can have unintended consequences. Generic switching is often driven by cost incentives, regulations and supply, but may raise concerns about equal bioavailability, therapeutic equivalence and about possible confusion for the patient. Integrated systems of care with active management of patient behaviors, including adherence, may minimize the impact of switching. This article is intended to present policy drivers and potential consequences of generic switching and the role of pharmacist education in minimizing patient risk using warfarin and the pharmaceutical distribution systems of the United States and Germany as examples.

Reproducibility of the anti-Factor Xa and anti-Factor IIa assays applied to enoxaparin solution.

Enoxaparin is a widely used subcutaneously administered antithrombotic agent comprising a complex mixture of glycosaminoglycan chains. Owing to this complexity, its antithrombotic potency cannot be defined by physicochemical methods and is therefore evaluated using an enzymatic assay of anti-Xa and anti-IIa activity. Maintaining consistent anti-Xa activity in the final medicinal product allows physicians to ensure administration of the appropriate dosage to their patients. Bioassays are usually complex and display poorer reproducibility than physicochemical tests such as HPLC assays. Here, we describe the implementation of a common robotic platform and standard release potency testing procedures for enoxaparin sodium injection (Lovenox, Sanofi, Paris, France) products at seven quality control sites within Sanofi. Qualification and analytical procedures, as well as data handling, were optimized and harmonized to improve assay reproducibility. An inter-laboratory study was performed in routine-release conditions. The coefficients of variation for repeatability and reproducibility in assessments of anti-Xa activity were 1.0% and 1.2%, respectively. The tolerance interval in reproducibility precision conditions, expressed as percentage potency, was 96.8-103.2% of the drug product target of 10,000 IU/ml, comparing favorably with the United States of America Pharmacopeia specification (90-110%). The maximum difference between assays in two different laboratories is expected to be 4.1%. The reproducibility characteristics of anti-IIa activity assessments were found to be similar. These results demonstrate the effectiveness of the standardization process established and allow for further improvements to quality control in Lovenox manufacture. This process guarantees closeness between actual and target potencies, as exemplified by the results of release assays obtained during a three-year period.

Tablet splitting and weight uniformity of half-tablets of 4 medications in pharmacy practice.

BACKGROUND: Tablet splitting is a common practice for multiple reasons including cost savings; however, it does not necessarily result in weight-uniform half-tablets. OBJECTIVES: To determine weight uniformity of half-tablets resulting from splitting 4 products available in the Jordanian market and investigate the effect of tablet characteristics on weight uniformity of half-tablets. METHODS: Ten random tablets each of warfarin 5 mg, digoxin 0.25 mg, phenobarbital 30 mg, and prednisolone 5 mg were weighed and split by 6 PharmD students using a knife. The resulting half-tablets were weighed and evaluated for weight uniformity. Other relevant physical characteristics of the 4 products were measured. RESULTS: The average tablet hardness of the sampled tablets ranged from 40.3 N to 68.9 N. Digoxin, phenobarbital, and prednisolone half-tablets failed the weight uniformity test; however, warfarin half-tablets passed. Digoxin, warfarin, and phenobarbital tablets had a score line and warfarin tablets had the deepest score line of 0.81 mm. CONCLUSION: Splitting warfarin tablets produces weight-uniform half-tablets that may possibly be attributed to the hardness and the presence of a deep score line. Digoxin, phenobarbital, and prednisolone tablet splitting produces highly weight variable half-tablets. This can be of clinical significance in the case of the narrow therapeutic index medication digoxin.

Implementing NICE guidelines on risk assessment for venous thromboembolism: failure, success and controversy.

PURPOSE: Venous thromboembolism (VTE) prophylaxis guidelines were originally published by the National Institute of Clinical Excellence (NICE) in April 2007. Controversy eclipsed their release. Consequently, the VTE prophylaxis publication was reviewed and republished in January 2010. The NICE guidelines recommend that all patients are assessed for risk before pharmacological prophylaxis is offered and reassessed at 24 hours to check adverse reactions; and that prophylaxis is appropriate. This paper aims to look at their implementation. DESIGN/METHODOLOGY/APPROACH: A prospective audit and re-audit in one orthopaedic department was completed to see how well the new guidelines were adhered to, find out first-hand what problems there were, and how they might be remedied. FINDINGS: Audit and re-audit highlighted that attaching an assessment tool to drug charts is plausible. RESEARCH LIMITATIONS/IMPLICATIONS: The study was limited to one centre and used a relatively weak research design. PRACTICAL IMPLICATIONS: As a process, the clinical impact of risk assessment for VTE is questionable as many patients will be high risk. Removing reassessment at 24 hours from the NICE guidance is recommended. ORIGINALITY/VALUE: The authors put the NICE guideline into clinical practice, demonstrating how effectively it can work with their method, but also highlighting its flaws.

Post-discharge compliance to venous thromboembolism prophylaxis in high-risk orthopaedic surgery: results from the ETHOS registry.

Venous thromboembolism (VTE) risk persists for several weeks following high-risk orthopaedic surgery (HROS). The ETHOS registry evaluated post-operative VTE prophylaxis prescribed, and actual VTE prophylaxis received, compared with the 2004 American College of Chest Physicians (ACCP) guidelines in HROS patients. We performed a subanalysis of ETHOS to assess patient compliance with ACCP-adherent prophylaxis after discharge and the factors predicting poor compliance. Consecutive patients undergoing hip fracture surgery, total hip arthroplasty, or knee arthroplasty were enrolled at discharge from 161 centres in 17 European countries if they had received adequate in-hospital VTE prophylaxis. Data on prescribed and actual prophylaxis received were obtained from hospital charts and patient post-discharge diaries. Good compliance was defined as percentage treatment intake ≥80% with no more than two consecutive days without treatment. A total of 3,484 patients (79.4%) received ACCP-adherent anticoagulant prescription at discharge and 2,999 (86.0%) had an evaluable patient diary. In total, 87.7% of evaluable patients were compliant with prescribed treatment after discharge. The most common reason for non-compliance (33.4%) was "drug was not bought". Injection of treatment was not a barrier to good compliance. Main factors affecting compliance related to purchase of and access to treatment, patient education, the person responsible for administering injections, country, and type of hospital ward at discharge. Within our study population, patient compliance with ACCP-adherent thromboprophylaxis prescribed at discharge was good. Improvements in patient education and prescribing practices at discharge may be important in further raising compliance levels in high-risk orthopaedic surgery patients.

Improving adherence to best-practice guidelines for venous thromboembolism risk assessment and prevention.

PURPOSE: The effectiveness of a program to improve adherence to best-practice guidelines for venous thromboembolism (VTE) risk assessment and prevention in a community hospital setting was evaluated. SUMMARY: Variation in the use of best-practice guidelines for VTE risk assessment and prevention with regard to the frequency of VTE risk assessment and the risk score assigned, as well as the communication of the risk of VTE and the need for prophylaxis to treating physicians, was found. To improve adherence to established guidelines, the responsibilities of a nurse case manager were expanded to serve as a single point of contact who was accountable for identifying high-risk patients and advocating for appropriate pharmacologic prophylaxis in the absence of contraindications. To facilitate the role of the nurse case manager, an automated VTE-risk-assessment tool was developed to reliably identify high-risk patients in real time. This intervention was evaluated from January 1 to June 30, 2010. Before the intervention, contraindications to anticoagulation were reported for 19.1% of high-risk patients not receiving prophylaxis and pharmacologic prophylaxis was ordered for 47.9% of high-risk patients without contraindications. During the course of the intervention, contraindications to anticoagulation were reported for 36.2% of high-risk patients not receiving prophylaxis and pharmacologic prophylaxis was ordered for 64.9% of high-risk patients without contraindications. CONCLUSION: The appointment of a nurse case manager trained in anticoagulation and the development of an automated VTE-risk-assessment tool to identify patients at high risk of VTE were associated with improved adherence to best-practice guidelines for VTE risk assessment and prevention.

"Leaning" the process of venous thromboembolism prophylaxis.

BACKGROUND: Lean principles have been used at Denver Health Medical Center since 2005 to streamline nonclinical processes. Despite allocation of significant resources, particularly the expense of low molecular weight heparin (LMWH), to prophylaxis of venous thromboembolism (VTE), the incidence of postoperative VTE was significantly worse than national benchmarks. VTE risk factors were not consistently assessed, and the prescribing of prophylaxis varied widely. Lean was employed to standardize and implement risk assessment and evidence-based VTE prophylaxis for the institution. METHODS: In a rapid improvement event, a multidisciplinary group formulated an evidence-based risk assessment tool and clinical practice guideline for VTE prophylaxis, with plans for hospitalwide implementation and monitoring. RESULTS: The effects were immediate and improved steadily with feedback to clinicians. Within six months, compliance with the standard approached 100%. One year after implementation, the use of LMWH decreased more than 60% below baseline, and the use of sequential compression devices decreased by nearly 30%. With increased use of unfractionated heparin, the cost savings on VTE prophylaxis exceeded $15,000 per month, for a total of $425,000 since implementation. Moreover, the incidence of VTE decreased markedly during the same period. By reducing VTE rates, a total cost savings of $6.2 million was estimated for the past 28 months. CONCLUSIONS: Applying Lean to the clinical management of VTE prophylaxis improved compliance with standards and saved the hospital a significant amount of money. This was achieved without compromising clinical outcomes. This experience could be replicated at other institutions.

Heparin quality control in the Brazilian market: implications in the cardiovascular surgery.

INTRODUCTION: The change in the heparin solution trade mark in Brazil that had been commonly used in cardiac surgery has shown increased number in the coagulopathy, re-exploration and other side effects in our Institution and others. METHODS: All four different heparin solutions available in the Brazilian market were studied in the Connective Tissue Lab, HUCFF, UFRJ and compared to the Liquemine (out of the market) and the international control solution. All samples were evaluated by magnetic nuclear resonance as well as their anticoagulant effectiveness. RESULTS: There were significant differences among them regarding the anticoagulant activity. It was also observed contamination with other dermatan sulfate, samples chemically degraded and with significant change in the molecular weight. CONCLUSION: Among the studied samples, none of them can offer security in cardiac surgeries on pump. None of them has demonstrated similar quality to Liquemine, which is not available in the Brazilian market.

Controle da qualidade das preparações de heparina disponíveis no Brasil: implicações na cirurgia cardiovascular / Heparin quality control in the Brazilian market: implications in the cardiovascular surgery

INTRODUÇÃO: A mudança na marca da heparina rotineiramente utilizada nas cirurgias cardíacas no Brasil tem sido acompanhada por aumento do número de casos de discrasia sanguínea, aumento de reoperações e efeitos adversos em nossa Instituição e em outras. MÉTODOS: Foram avaliadas no Laboratório de Tecido Conjuntivo do HUCFF/UFRJ, quatro preparações disponíveis e comparadas à heparina retirada do mercado (Liquemine) e ao padrão de controle internacional. As preparações de heparina foram submetidas à ressonância nuclear magnética para avaliação da integridade estrutural, bem como avaliação de sua eficácia anticoagulante. RESULTADOS: Houve diferença significativa quanto à atividade anticoagulante entre as amostras. Também se observou a presença de contaminação com dermatam sulfato, amostras degradadas quimicamente e com significativa alteração do peso molecular. CONCLUSÃO: Das amostras estudadas, nenhuma atendeu aos requisitos de segurança para utilização em cirurgias cardíacas com circulação extracorpórea. Nenhuma delas apresentou a qualidade semelhante ao Liquemine, não mais disponível no mercado brasileiro.

INTRODUCTION: The change in the heparin solution trade mark in Brazil that had been commonly used in cardiac surgery has shown increased number in the coagulopathy, re-exploration and other side effects in our Institution and others. METHODS: All four different heparin solutions available in the Brazilian market were studied in the Connective Tissue Lab, HUCFF, UFRJ and compared to the Liquemine (out of the market) and the international control solution. All samples were evaluated by magnetic nuclear resonance as well as their anticoagulant effectiveness. RESULTS: There were significant differences among them regarding the anticoagulant activity. It was also observed contamination with other dermatan sulfate, samples chemically degraded and with significant change in the molecular weight. CONCLUSION: Among the studied samples, none of them can offer security in cardiac surgeries on pump. None of them has demonstrated similar quality to Liquemine, which is not available in the Brazilian market.

Variability of heparins and heterogeneity of low molecular weight heparins.

Chemical and physical characteristics, building blocks, constitutive disaccharides, sulfation degree, and biological activities of heparins (UFHs) and of low molecular weight heparins (LMWHs) obtained by different depolymerization processes are examined comparatively in terms of structure characteristics, content of 1,6-anhydro rings, and other fingerprints. The heterogeneity of different LMWHs depends on different manufacturing processes and on particular specifications of pharmacopoeias. The reported examples prove that the variability among samples of LMWHs manufactured by the same process is quite limited. Most of the variability is derived from the parent UFH. In contrast, fingerprint groups and residues are specific to the depolymerization process and their extent can be roughly controlled through the process parameters.