Effects of low molecular weight heparin on alveolar bone loss in wistar rats

Abstract This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Resumo O presente estudo objetivou verificar o efeito da heparina de baixo peso molecular (HBPM) sob a perda óssea alveolar (POA), contagem de células sanguíneas, megacariócitos e adipócitos em ratos Wistar machos. Quarenta ratos Wistar de 60 dias foram randomicamente divididos em quatro grupo: Controle (C), Doença Periodontal (DP), Heparina (Hp) e Heparina + Doença Periodontal (Hp+DP). HBPM foi aplicada durante 60 dias em doses de 1 mL/kg/dia. Coletas sanguíneas foram realizadas nos dias 0, 30 e 60. No dia 49, os grupos DP e Hp+DP receberam indução de doença periodontal por ligadura ao redor do segundo molar superior direito. No lado esquerdo, verificou-se perda óssea alveolar espontânea. A média de POA no lado com ligadura mostrou-se estatisticamente diferente entre os grupos C (0,35±0,07 mm) e Hp+PD (0,49±0,09 mm) (p<0,001), entre os grupos DP (0,55±0,11 mm) e Hp (0,32±0,06 mm) (p<0,001) e entre os grupos Hp e Hp+DP (p<0,001). Nenhuma diferente significativa foi observada entre os grupos no lado sem ligadura. Peso dos animais, consumo de ração e ingestão de água não mostraram diferenças significativas entre os grupos. Megacariócitos e adipócitos foram contados por microscopia óptica e nenhuma diferença significativa foi encontrada. Dentro dos grupos, houve um aumento e uma diminuição, respectivamente, na contagem de linfócitos (p=0,005 no grupo C e p=0,009 no grupo Hp+DP somente) e leucócitos (p=0,003 no grupo C, p=0.001 no grupo DP e p=0,002 no grupo Hp e Hp+DP). Não houve diminuição no número de plaquetas nos três períodos de coleta. HBPM não foi capaz de modificar a POA, porém modificou a contagem de células sanguíneas, especialmente aumentando o número de linfócitos.

B-type Natriuretic Peptide May be Unsuitable for Diagnosing Central.

We describe a case of a 90-year-old male admitted to the emergency department with deep vein thrombosis and central acute pulmonary embolism. Despite a remarkably increased value of D-dimer and a modestly elevated concentration of cardiac troponin I, the value of B-type natriuretic peptide was found to be non-diagnostic. Limited to this single case report, our evidence suggests that the measurement of natriuretic peptides is questionable for diagnosing central acute pulmonary embolism in the emergency department.

Catéter subcutáneo para la administración de heparina de bajo peso molecular en pediatría / Subcutaneous catheter used for administration of low-molecular-weight-heparin in pediatrics

Introduction: Subcutaneous catheter is a device easy to assemble, which was created for the administration of insulin in diabetic patients, especially in children, aiming to reduce the number of punctures, pain and anxiety of patients and their parents. Objective: To describe the experience using the catheter for subcutaneous administration of low molecular weight heparin (LMWH) in hospitalized pediatric patients. Patients and Method: A prospective descriptive study in 28 patients who used 87 subcutaneous catheters for the administration of LMWH in the Pediatric Service of the Universidad Catolica de Chile between July, 2010 and November, 2011. Results: Complications associated with the catheter had an incidence of 33 percentin total catheters evaluated; the most frequent complication was the presence of hematoma at the site of insertion (26 percent). These complications occurred more frequently in male (38 percent versus 31 percent in females) and younger patients (9 months versus 12 months), who received dalteparin (54 percent versus 30 percent of other types of heparin) administered every 24 hours (41percent versus 30 percent, administered every 12 hours), and when the catheter was located on both thighs (36 percent versus 32 percent in both arms); however, these differences were not statistically confirmed. Conclusion: The subcutaneous catheter is a good technique to be considered for LMWH in children as it presents minor complications for drug administration.

Introducción: El catéter subcutáneo es un dispositivo de fácil instalación, el cual fue ideado para la administración de insulinas en pacientes diabéticos, especialmente en pediatría, con el fin de disminuir el número de punciones, el dolor y la ansiedad de los pacientes y sus padres. Objetivo: Describir la experiencia del uso del catéter subcutáneo para la administración de heparina de bajo peso molecular (HBPM) en pacientes pediátricos hospitalizados. Pacientes y Método: Estudio descriptivo prospectivo en 28 pacientes que utilizaron 87 catéteres subcutáneos instalados para la administración de HBPM, en el Servicio de Pediatría de la Pontificia Universidad Católica de Chile en el período comprendido entre los meses de julio de 2010 y noviembre de 2011. Resultados: Las complicaciones asociadas al catéter presentaron una incidencia de 33 por ciento en el total de catéteres evaluados, siendo la más frecuente la presencia de hematoma en el sitio de inserción (26 por ciento). Estas complicaciones se presentaron con mayor frecuencia en pacientes de sexo masculino (38 por ciento versus 31 por ciento en sexo femenino) de menor edad (9 meses versus 12 meses), con indicación de dalteparina (54 por ciento versus 30 por ciento con otros tipos de heparina) administrada cada 24 h (41 por ciento versus 30 por ciento cuando fue administrada cada 12 h), y cuando el catéter estuvo ubicado en ambos muslos (36 por ciento versus 32 por ciento en ambos brazos); sin embargo, estas diferencias no fueron confirmadas estadísticamente. Conclusión: El catéter subcutáneo es una buena técnica a considerar para la administración de HBPM en la edad pediátrica, ya que permite la administración del medicamento con complicaciones leves asociadas a su uso.

Heparina de baixo peso molecular em gestantes e puérperas com trombofilia / Low molecular weight heparin in pregnant women and postpartum women with thrombophilia

A trombofilia se caracteriza como um grupo de distúrbios da coagulação associados a uma predisposição a eventos trombóticos como trombose venosa profunda e embolia pulmonar potencialmente fatal. Heparina de baixo peso molecular: O uso da heparina de baixo peso molecular em gestantes (e puérperas) pode ser observado em diversas situações, como: 1. Tratamento de tromboembolismo venoso; 2. Tromboprofilaxia e 3. Prevenção de eventos obstétricos adversos (pre-eclâmpsia, retardo de crescimento fetal intrauterino, natimortos, abortamentos de repetição e outros). Alternativas terapêuticas: Dentre as alternativas terapêuticas para a profilaxia ou tratamento de eventos relacionados à trombofilia, algumas opções descritas na literatura científica internacional (e inclusive utilizados como comparadores em estudos clínicos) são: Heparina não-fracionada, Aspirina, Controle clínico (ou não utilização de tromboprofilaxia).Citérios de seleção e exclusão de artigos: Por se tratar de uma questão sobre a eficácia e segurança de um tratamento de determinada situação clínica, as evidências científicas de maior qualidade são as revisões sistemáticas de estudos clínicos controlados randomizados, seguidas de ensaios clínicos controlados randomizados. O principal critério de seleção para esse parecer é que o desenho do estudo contemplasse uma dessas classificações. Apenas estudos incluindo pacientes gestantes ou puérperas com trombofilia tratadas com heparina de baixo peso molecular foram considerados. Avaliações de tecnologia em saúde sobre a eficácia da heparina de baixo peso molecular em pacientes gestantes ou puérperas com trombofilia também foram pesquisadas. Alguns critérios de exclusão foram determinados: registros de ensaios controlados em andamento, estudos de custo-efetividade, avaliações econômicas, revisões narrativas ou estudos de fase I ou II. Com base nesses critérios de inclusão e exclusão, foram selecionadas 5 (cinco) revisões sistemáticas aplicáveis ao tema. Conclusões: Os estudos localizados demonstraram claramente a limitação das \r\nevidências científicas atualmente disponíveis sobre alguma vantagem clínica ou obstétrica da heparina de baixo peso molecular em relação à heparina não fracionada, quando analisados os quesitos fundamentais de segurança ou eficácia. Duas revisões sistemáticas não localizaram sequer um estudo de boa qualidade que preenchesse os critérios de inclusão propostos. Portanto, até o momento, com grau de recomendação "A", a melhor evidência científica disponível sugere que não haveria diferença, em termos de segurança e \r\neficácia, quando comparado o uso da heparina de baixo peso molecular em relação à heparina não fracionada em mulheres grávidas com trombofilia. Deve-se destacar, no entanto, que há uma lacuna importante em termos de evidências científicas de boa qualidade e que, inclusive, foram identificados estudos que não demonstraram superioridade do uso de heparinas de baixo peso molecular quando comparados a placebo ou não tratamento. Para avaliar uma possível superioridade da heparina de baixo peso molecular em relação à heparina não fracionada em mulheres grávidas com trombofilia, ainda são necessários estudos clínicos \r\nrandomizados controlados com boa qualidade metodológica, incluindo randomização, grupo controle e seguimento adequado. Há a possibilidade de que, dentre os estudos em andamento (ou já concluídos e \r\nainda não publicados), sejam apresentadas evidências científicas que possam colaborar na resposta das questões ainda pendentes de esclarecimentos. Recomendação da CONITEC: Os membros da CONITEC presentes na 7ª reunião do plenário do dia 02/08/2012 apreciaram a proposta de incorporação da heparina de baixo peso molecular em gestantes e puérperas com trombofilia e, decidiram, por unanimidade, pela não incorporação do medicamento. A Portaria nº 32, de 3 de julho de 2013 - Torna pública a decisão de não incorporar a heparina de baixo peso molecular para o tratamento de gestantes e puérperas com trombofilia no Sistema Único de Saúde (SUS).

Segurança da ablação de fibrilação atrial com RNI terapêutico: comparação com a transição com heparina de baixo peso / Safety of ablation for atrial fibrillation with therapeutic INR: comparison with transition to low-molecular-weight heparin

FUNDAMENTO: O manejo ideal da anticoagulação oral (ACO) no período pré- e pós-ablação de fibrilação atrial (FA) ainda é motivo de controvérsia. OBJETIVO: Comparar duas estratégias de anticoagulação: suspensão da warfarina com a utilização de heparina de baixo peso molecular (HBPM) e a realização da ablação sem a suspensão da warfarina, mantendo o RNI terapêutico (entre 2,0 e 3,0). MÉTODOS: 140 pacientes (pt) portadores de FA persistente/ permanente submetidos à ablação por cateter de FA foram divididos em dois grupos: no grupo I (70 pt), a warfarina foi suspensa cinco dias antes do procedimento e utilizada terapia de transição com HBPM (enoxaparina 1 mg/kg 2x/dia pré-ablação e 0,5 mg/kg 2x/dia após o procedimento); no grupo II (70 pt), a warfarina não foi suspensa e o procedimento foi realizado com RNI terapêutico. Ambos os grupos receberam heparina intravenosa (TCA > 350 seg) durante o procedimento. RESULTADOS: No Grupo I, observou-se complicação hemorrágica maior (1,4 por cento) e 4 pt (5,7 por cento) com complicações hemorrágicas menores. No Grupo II, 2 pt (2,8 por cento) apresentaram complicações hemorrágicas menores e 1 pt apresentou sangramento maior; porém, este ocorreu após uso de HBPM por RNI < 2,0. Não houve complicação tromboembólica ou morte cardiovascular nos dois grupos após 16 ± 8 meses. CONCLUSÃO: A realização de ablação por cateter de FA sem a suspensão de ACO e RNI terapêutico é uma estratégia semelhante em segurança e eficácia quando comparada à tradicional transição com HBPM, evitando um período inicial pós-ablação de anticoagulação potencialmente inadequada.

BACKGROUND: The ideal management of oral anticoagulation (OAC) before and after catheter ablation for atrial fibrillation (AF) is still controversial. OBJECTIVE: To compare two anticoagulation strategies for catheter ablation for AF: warfarin withholding and use of low-molecular-weight heparin (LMWH); and maintenance of warfarin and therapeutic INR (between 2.0 and 3.0). METHODS: 140 patients (pt) with persistent/permanent AF undergoing catheter ablation for AF were divided into two groups: Group I (70 pt), in which warfarin was withheld five days prior to the procedure and transition to LMWH was used (enoxaparin: 1 mg/kg 2x/day before ablation, and 0.5 mg/kg 2x/day after ablation); Group II (70 pt), in which warfarin was not withheld and the procedure was performed with therapeutic INR. Both groups received intravenous heparin (ACT > 350 seconds) during ablation. RESULTS: In Group I, one pt (1.4 percent) had a major hemorrhagic complication and four pts (5.7 percent) had minor hemorrhagic complications. In Group II, two pts (2.8 percent) had minor hemorrhagic complications and one pt had a major bleeding, which occurred after using LMWH due to INR < 2.0. None of the groups had thromboembolic complications or cardiovascular death over a period of 16 ± 8 months. CONCLUSION: Catheter ablation for AF without withholding OAC and with therapeutic INR is a strategy that has similar safety and efficacy when compared with the traditional transition to LMWH, avoiding the potentially inadequate anticoagulation of the initial post-ablation period.

Heparinas de bajo peso molecular en pacientes con enfermedad renal crónica ¿Es seguro su uso? / Are low-molecular-weight heparins safe in patients with chronic kidney disease?

Due to their effcacy and convenience, low-molecular-weight heparins (LMWH) are used as sustitutes of unfractionated heparin. Unfortunately, most of the evidence about safety and usefulness of LMWH have excluded patients with chronic kidney disease (CKD), in whom their elimination clearance is reduced, allowing an increased anticoagulant effect. Accordingly, there is a growing number of reports about major and fatal bleeding episodes in this group of patients using LMWH. At the present stage of knowledge, there is no defnitive cut-off value of renal function to adjust the doses or avoid the administration of LMWH, making their effects unpredictable in patients with CKD. Hence, it is reasonable to avoid the use of these drugs in patients with CKD, while awaiting for more evidence that supports their safer use.

Evolução de idosos em Síndrome Coronariana Aguda sem Supradesnivelamento do Segmento de ST (SCASS) submetidos a dois diferentes protocolos / Progress of elderly patients with non-ST-Segment Elevation Acute Coronary Syndrome subjected to two different protocols

Fundamento: Recomenda-se a conduta invasiva para pacientes de alto risco na SCASS de ST. O intervalo da estratificação angiográfica, a qualitativa intervenção farmacológica e percutânea coronariana admissional mantêm-se controversos nos idosos e assim, seus resultados tardios são desconhecidos. Objetivo: Avaliar a evolução tardia de dois diferentes protocolos de tratamento em idosos com SCASS de ST. Métodos: Estudo prospectivos de 84 consecutivos pacientes em dois grupos, segundo critérios de inclusão e exclusão (G1 e G2). O acaompanhamento foi de 09/2003 a 12/2005. O peptídeo natiurético tipo B (BNP) foi dosado aos 6 meses (P1), entre 6 meses e 1 ano (P2) e após 1 ano (P3). Utilizou-se o teste t de Student e o exato de Fisher para variáveis contíruas e discretas, respectivamente. Aplicou-se o teste de Wilcoxon (Gehan) para comparar as curvas de sobrevida. Consideraram significantes valores de p menor que 0,05...

Estudo de segurança e eficácia da enoxaparina sódica na profilaxia e terapêutica antitrombótica / Safety and efficacy of sodium enoxaparin in anti-thrombotic prophylaxis and treatment

JUSTIFICATIVA E OBJETIVOS: O uso de heparina de baixo peso molecular (HBPM) na profilaxia ou terapêutica de diversas doenças ou síndromes é de grande importância na prática clínica. O objetivo deste estudo foi avaliar a segurança e a eficácia da enoxaparina sódica, teste (ENOX-T) comparada ao medicamento de referência (ENOX-R). MÉTODO: Foi realizado estudo prospectivo, aleatório, comparativo, unicêntrico e aberto envolvendo pacientes com indicação de profilaxia ou tratamento antitrombótico. Foram incluídos 100 pacientes divididos em 2 braços: profilático (n = 50) e terapêutico (n = 50) divididos em 2 grupos para cada braço (grupo 1: ENOX-R e grupo 2: ENOX-T). Analisou-se em cada segmento os dados clínicos e laboratoriais. A atividade do anti-fator Xa foi aferida em três momentos: basal (1ª avaliação); 1º ou 2º dia (2ª avaliação) e 5º a 7º dia (3ª avaliação). O ultra-som Doppler dos membros inferiores foi realizado na 2ª ou 3ª avaliação do braço profilático. RESULTADOS: Os resultados demonstraram homogeneidade dos grupos nos 2 braços (profilático e terapêutico) quanto a sexo, idade, índice de massa corpórea, creatinina sérica e Apache II. Os valores do anti-fator Xa nos braços profilático e terapêutico demonstraram eficácia adequada dos medicamentos, sem diferença clínica ou estatística entre ambos. A ocorrência de eventos adversos não mostrou diferença clínica ou estatística entre os medicamentos. No braço profilático o ultra-som de membros inferiores acrescentou informações úteis sobre a eficácia dos fármacos estudados. CONCLUSÕES: A enoxaparina sódica teste (ENOX-T) foi segura e eficaz nos pacientes analisados e equivalente ao medicamento de referência (ENOX-R).

BACKGROUND AND OBJECTIVES: Use of low molecular weight heparins (LMWH), either prophylactic or therapeutic, is of most importance in several syndromes and diseases in daily clinical practice. Our objective in this clinical trial was to evaluate safety and efficacy of test sodium enoxaparin (ENOX-T) compared to the reference drug (ENOX-R). METHODS: We conducted a prospective, randomized, comparative, unicentric and open-labeled trial including patients with either prophylactic or therapeutic anti-thrombotic indications. A total of 100 patients were enrolled in two branches: prophylactic (n=50) and therapeutic (n=50) and two groups for each branch (group 1: ENOX-R and group 2: ENOX-T). We analyzed clinical and laboratory data in each segment. Anti-factor Xa was measured in three different moments: baseline (1st evaluation); 1st or 2nd day (2nd evaluation) and 5th to 7th day (3rd evaluation). Doppler-sonography of inferior limbs was performed on all patients in prophylactic group on 2nd or 3rd evaluation. RESULTS: The data showed that both branches (prophylactic and therapeutic) were homogenous in regard of sex, age, body mass index (BMI), serum creatinine and APACHE II severity score at admission. Anti-factor Xa results, in both prophylactic and therapeutic branches, showed expected efficacy to both drugs, without any clinical or statistical difference between them. Adverse events incurred in both groups in a similar way, without any clinical or statistical difference between them. In prophylactic branch, Doppler-sonography of inferior limbs added useful information on drugs efficacy. CONCLUSIONS: We conclude that test sodium enoxaparin (ENOX-T) was effective and safe in our patient's cohort and equivalent to reference drug (ENOX-R).

Comparative efficacy of once daily parnaparin and unfractionated heparin in unstable angina pectoris: PRIME CARE study.

BACKGROUND: This study sought to compare the efficacy of low molecular weight heparin, parnaparin and unfractionated heparin in Indian patients presenting with unstable angina pectoris. METHODS AND RESULTS: In this randomized, prospective and multicentre trial 897 adult patients of both sexes suffering from unstable angina were included. All patients also received oral aspirin and adequate anti-anginal treatment as per their individual needs. Patients in unfractionated heparin group received unfractionated heparin as an intravenous bolus of 5000 IU followed by an intravenous infusion of 800 to 1000 IU/hour for 48 hours, followed by 5000 IU subcutaneously every 6 hours for 5 days. The patients in the other group were treated with parnaparin sodium 6400 IU subcutaneously once daily for 7 days. In the unfractionated heparin group there were 446 patients (310 males, 136 females) with a mean age of 55.9 + 12.27 years and in parnaparin group 451 patients (312 males, 139 females) with a mean age of 57.6 +/- 11.19 years. Both the groups were similar with respect to age and sex (p = 0.89 and 0.068, respectively). The associated cardiovascular risk factors such as diabetes, hypertension, dyslipidemia, previous myocardial infarction and previous coronary artery bypass grafting/percutaneous transluminal coronary angioplasty were similar in both the groups. At the end of 7 days, the primary end points (death, myocardial infarction, or need for myocardial revascularization) were reported in 33 (7.32%) patients in parnaparin group and 51 (11.43%) patients in unfractionated heparin group. This difference was statistically significant. At the end of 30 days, data from 330 patients from parnaparin group and 334 patients from unfractionated heparin group was available for analysis. The cumulative event rate of primary end points at the end of 30 days was reported in 40 (12.12%) patients in parnaparin group and in 73 (21.86%) patients in unfractionated heparin group. This difference was statistically significant. Two episodes of major bleeding each were reported in both the groups. Minor bleeding was reported by 12 (2.66%) patients in parnaparin group and by 115 (25.8%) patients in unfractionated heparin group. This difference was statistically significant. CONCLUSIONS: Addition of parnaparin to the standard treatment of unstable angina significantly reduced the incidence of combined triple end points of death, myocardial infarction and need for revascularization when compared to unfractionated heparin. This benefit was observed at 7 days as well as at 30 days of follow-up. The incidence of minor bleeding was significantly less in patients treated with parnaparin. Thus, once daily administration of parnaparin 6400 IU as a fixed dose is a safe and effective alternative to unfractionated heparin in the treatment of unstable angina.

Comparison of unfractionated heparin vs low molecular weight heparin in the treatment of acute deep vein thrombosis

To compare the results of unfractionated heparin [UFH] with low molecular weight heparin in the treatment of acute deep vein thrombosis of lower limb. Randomized control trial. Bolan Medical Complex Hospital, Quetta from January 2002 to July 2003. Thirty patients who presented with acute deep vein thrombosis of lower limb, confirmed by either Doppler ultrasonography or venography, were selected for the study. Patients were divided randomly into two groups for treatment. Group 1 was started with unfractionated heparin while group 2 with low molecular weight heparin. Comparison of two treatments to determine the efficacy was done by certain criteria like pain improvement, reduction in swelling, alteration in bleeding profile, complications of therapy, recurrence, morbidity and mortality. The age of the patients ranged from 16-82 years. There were 15 females [50.00%] and 15 males [50.00%]. Pain and swelling were present in all patients [100%], while temperature and superficial vein dilation in 43.3% and 30% respectively. The distribution of DVT in left lower limb was in 13 patients [43.33%], right lower limb involvement in 12 patients [40.00%] and both limbs involvement in 5 patients [16.67%]. In group 1 improvement in pain occurred after 4th day in 13 patients, while in group 2 before 4th day in 8 patients [p-value=0.068]. Improvement in swelling was observed after 6th day in 11 patients [group 1], while before 6th day in 8 patients [group 2] [p-value=0.171]. Bleeding time was prolonged in 5 patients in group1and statistically found significant [p-value=0.014], while in group 2 it was normal. Thromboembolism in 3 patients and major bleeding was observed in 2 patients in group 1, while in group 2 it was normal. Recurrence was reported in 2 patients in group 1 and 1 patient in group 2 [p-value 0.0815]. The hospital stay was more than 10 days in group1 [12 patients], and less than 10 days in group 2 [13 patients]. It was found statistically significant [p-value=0.001]. Three patients died in group 1, while no mortality was observed in group 2. Treatment with low melecular weight heparin [LMWH] has good patient compliance and is easy to administer. LMWH has an advantage over UFH due to its normal bleeding profile and significantly less hospital stay

Reviparin sodium clivarine: a review of its therapeutic use.

Reviparin sodium (clivarine) is a second generation LMWH, developed with the aim of maximising the antithrombotic action while minimising the risk of haemorrhage. Clivarine has been extensively studied in acute coronary syndrome. Various clinical studies in unstable angina and acute coronary syndrome have proved that clivarine in a dosage of 3436anti-Xa units twice daily is an effective antithrombotic agent. Clivarine has been shown to be as effective as unfractionated heparin (UFH) in thromboprophylaxis and it has less incidence of local haematoma at injection site. At a daily dose of 1432 IU anti-Xa it was found to be as effective as UFH in preventing deep vein thrombosis (DVT) in moderate risk surgery (general and abdominal) and reducing to a significant extent DVT in patients with brace immobilisation of the legs. At a daily dose of 3436 IU anti-Xa reviparin was as effective as UFH or enoxaparin in preventing DVT in high risk orthopaedic surgery and as effective as UFH in prevention of DVT and/or pulmonary embolism (PE) and/or mortality in high risk orthopaedic surgery. In patients with acute venous thrombo-embolism (VTE), reviparin was more effective than UFH in thrombus reduction and at least as effective as UFH in the prevention of clinical recurrence of DVT and/or PE. The use of reviparin is associated with a similar or lower incidence of bleeding complications than UFH. The benefits of reviparin sodium have been demonstrated in a number of clinical trials.

Evaluación de factores predisponentes para el sangrado mediastinal en cirugía de revascularización miocárdica: Papel del ácido acetilsalicílico, otros antiagregantes plaquetarios, y anticoagulantes / Evaluation of Predisposing Factors for Mediastinal Bleeding in Myocardial Revascularization Surgery: Role of Acetylsalicylic Acid, Other Platelet Adhesion Inhibitors, and Anticoagulants

Propósito del trabajo: Determinar los factores predisponentes para sangrados perioperatorios en cirugía de revascularización miocárdica y establecer el papel de ácido acetilsalicílico, otros antiagregantes plaquetarios, y anticoagulantes, en la ocurrencia de estos sangrados. Método: Se realizó un análisis multivariado de 251 pacientes sometidos a cirugía de revascularización miocárdica en el año 2002. Resultados: En la administración prequirúrgica de ácido acetilsalicílico no se encontró diferencia significativa para la ocurrencia de sangrado perioperatorio importante. No existió incremento significativo en la transfusión de unidades de paquetes globulares, plaquetas, crioprecipitados. Los pacientes con administración de heparina no fraccionada y de bajo peso molecular, tuvieron un sangrado transoperatorio significativamente mayor (p < 0.001) que los pacientes sin este fármaco. El empleo del resto de los fármacos estudiados, no incrementó la cantidad de sangrado ni la administración de hemoderivados. Conclusiones: No existe evidencia estadística que justifique suspender la administración de antiagregantes plaquetarios en los pacientes con síndromes coronarios urgentes o electivos, a quienes se les someta a cirugía de revascularización miocárdica. Sin embargo, resultaría conveniente suspender la administración de heparina no fraccionada y de bajo peso molecular, a pacientes sometidos a cirugía de revascularización miocárdica en forma electiva.

Objective: To determine the main factors for perioperative mediastinal bleeding during coronary artery by-pass grafting and to establish the role of acetylsalicylic acid, other inhibitors of platelet adhesion, and anticoagulants in its occurrence. Methods: A multivariate analysis was performed to the data obtained from 251 patients subjected to coronary artery by-pass grafting in the year 2002. Results: There were no significant differences for the occurrence of perioperative bleeding induced by the preoperative administration of acetylsalicylic acid. No significant increment in the need for blood, platelet, or cryoprecipitates transfusion existed. Patients receiving non-fractionated or low molecular weight heparin had a significantly greater (p < 0.001) transoperative bleeding than patients without this drug. Administration of the other studied drugs did not increase either mediastinal bleeding or the need for blood derivatives. Conclusions: No statistical evidence was found to suspend administration of inhibitors of platelet adhesion in patients with coronary syndromes, subjected to coronary artery by-pass grafting. However, data obtained suggest the convenience of suspending administration of low molecular weight or non-fractionated heparin to patients subjected electively to coronary artery by-pass grafting.