Effect of anticoagulant adjustment on prothrombin time test using two different PT reagents in patients with elevated hematocrit.

The recommendations for adjustment of citrate volume in sample tubes with high hematocrit (Ht) are based on indirect studies of underfilled tubes or artificially constructed Ht values. The aim of this study was to evaluate the effect of citrate volume adjustment in sample tubes from patients with hematocrit >55% using two different prothrombin time (PT) tests. METHODS: Paired citrate-adjusted and unadjusted blood specimens were obtained from 181 patients from the pulmonary hypertension ambulatory with high Ht values and on warfarin therapy. The samples were tested using recombinant human tissue factor (RTF) and reagents extracted from rabbit brain (HS Plus). The results are expressed as the international normalized ratio (INR). The correlation and percent change (% change) between sample pairs were calculated. RESULTS: INR-RTF results from adjusted and unadjusted citrate blood specimens showed a strong correlation (R2 â€‹= â€‹0.8226, p â€‹< â€‹0.0001). The INR median was 2.25 (95% CI 2.10 to 2.41) for citrate-adjusted samples and was 2.22 (95% CI 2.06 to 2.38) for citrate-unadjusted samples. For samples with Ht >62%, the % change between sample pairs was >10%. Results using HS Plus showed a moderate correlation between citrate-adjusted and unadjusted samples (R2 â€‹= â€‹0.4267, p â€‹< â€‹0.0001). The INR median was 2.51 (95% CI 2.35 to 2.68) for citrate-adjusted samples and 3.45 (95% CI 3.11 to 3.80) for citrate-unadjusted samples. For samples with Ht>55%, the % change between sample pairs was higher than 10%. CONCLUSION: Our data demonstrate that in patients with polycythemia on warfarin therapy, INR-RTF does not require anticoagulant adjustment for assessment of samples with Ht <62%.

Routine Coagulation Tests in Patients With Nonvalvular Atrial Fibrillation Under Dabigatran and Rivaroxaban Therapy: An Affordable and Reliable Strategy?

Dabigatran and rivaroxaban, direct oral anticoagulants (DOACs), affect coagulation tests, and knowledge of their effects is important for therapeutic monitoring. Our aim was to examine the association between DOAC levels and routine coagulation tests in patients with nonvalvular atrial fibrillation. Samples from patients receiving dabigatran (150 mg) and patients receiving rivaroxaban (20 mg) were collected 2 hours after drug intake. Direct oral anticoagulant concentrations were determined using direct Hemoclot thrombin inhibitor (HTI) assay (HTI test) and a direct Xa inhibitor (Anti Xa-Riva). The routine coagulation measured included activated partial thromboplastin time (aPTT) and prothrombin time (PT). The median plasmatic dabigatran was 128.3 ng/mL (95% confidence interval [CI]: 93.7-222.6 ng/mL). The HTI exhibited a good correlation with aPTT ( R2 = 0.74; P < .0001). The median plasmatic rivaroxaban was 223.9 ng/mL (95% CI: 212.3-238.9 ng/mL). Anti-Xa-Riva correlated with PT ( R2 = 0.69, P< .0001) and aPTT (R2 = 0.36, P < .001), but prolonged PT results were obtained, even below the rivaroxaban therapeutic range (20%). The routine coagulation tests were able to identify out of therapeutic range concentrations for dabigatran and rivaroxaban. We suggest the use of these screening tests to better understand and monitor the subtherapeutic concentrations of these DOACs.

Brazil nut ingestion increased plasma selenium but had minimal effects on lipids, apolipoproteins, and high-density lipoprotein function in human subjects.

The Brazil nut (Bertholletia excelsa) of the Amazon region is consumed worldwide. It is rich in both monounsaturated fatty acids and polyunsaturated fatty acids and is known for its high selenium content. This study tested the hypothesis whether the consumption of this nut could affect the plasma lipids and apolipoproteins and some functional properties of the antiatherogenic high-density lipoprotein (HDL). Fifteen normolipidemic subjects aged 27.3 +/- 3.9 years and with body mass index of 23.8 +/- 2.8 kg/m(2) consumed 45 g of Brazil nuts per day during a 15-day period. On days 0 and 15, blood was collected for biochemical analysis, determination of HDL particle size, paraoxonase 1 activity, and lipid transfer from a lipoprotein-like nanoparticle to the HDL fraction. Brazil nut ingestion did not alter HDL, low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-I, or apolipoprotein B concentrations. HDL particle diameter and the activity of antioxidative paraoxonase 1, mostly found in the HDL fraction, were also unaffected. Supplementation increased the reception of cholesteryl esters (P < .05) by the HDL yet did not alter the reception of phospholipids, free cholesterol, or triacylglycerols. As expected, plasma selenium was significantly increased. However, the consumption of Brazil nuts for short duration by normolipidemic subjects in comparable amounts to those tested for other nuts did not alter serum lipid profile. The only alteration in HDL function was the increase in cholesteryl ester transfer. This latter finding may be beneficial because it would improve the nonatherogenic reverse cholesterol transport pathway.

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).

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

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).