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Unlabelled: In the last few years, the number of anticoagulated patients has significantly increased and, as a consequence, so have hemorrhagic complications due to this therapy. We analyzed gastrointestinal (GI) bleeding because it is the most frequent type of major bleeding in these patients, and we hypothesized that they would have lesions responsible for GI bleeding regardless of the intensity of anticoagulation, although excessively anticoagulated patients would have more serious hemorrhages., Objectives: To study the characteristics of anticoagulated patients with GI bleeding and the relationship between the degree of anticoagulation and a finding of causative lesions and bleeding severity., Patients and Methods: We prospectively studied 96 patients, all anticoagulated with acenocoumarol and consecutively admitted to hospital between 01/01/2003 and 09/30/2005 because of acute GI bleeding. We excluded patients with severe liver disease, as well as nine patients with incomplete details., Results: The incidence of GI bleeding requiring hospitalization was 19.6 cases/100,000 inhabitants-year. In 90% of patients, we found a causative (85% of upper GI bleeding and 50% of lower GI bleeding) or potentially causative lesion, and 30% of them required endoscopic treatment, without differences depending on the intensity of anticoagulation. No relationship was found between the type of lesions observed and the degree of anticoagulation in these patients. Patients who received more intense anticoagulation therapy had more severe hemorrhages (23% of patients with an INR ≥4 had a life-threatening bleed versus only 4% of patients with INR <4)., Conclusions: We found an incidence of 20 severe GI bleeding episodes in anticoagulated patients per 100,000 inhabitants-year, with no difference in localization or in the frequency of causative lesions depending on the intensity of anticoagulation. Patients receiving more intense anticoagulation had more severe GI bleeding episodes., (Copyright © 2013 Elsevier España, S.L. and AEEH y AEG. All rights reserved.)

Summary Background: There is currently intense debate as to whether pharmacogenetic algorithms for estimating the initial dose of coumarins provide a more accurate dose than the fixed-dose approach. Recently, it has been suggested that the greatest benefit of pharmacogenetic algorithms is observed in patients with extreme dose requirements., Objectives: To identify clinical and genetic factors that better characterize patients who need extreme acenocoumarol doses for steady anticoagulation state., Patients/methods: We reviewed 9538 patients with a steady acenocoumarol dose from three Spanish hospitals, selecting 83 who took or= 30.00 mg week(-1) (p95). We also selected patients matched by gender and age taking 13.50-14.00 mg week(-1) (p50). We genotyped VKORC1 (rs9923231), CALU (rs1043550), GGCX (rs699664), CYP2C9 (rs1799853; rs1057910), CYP4F2 (rs2108622) and F7 (rs5742910) single-nucleotide polymorphisms (SNPs)., Results: Comparison between p5 and p95 revealed five parameters with significant differences: body surface area (BSA) (P = 0.006), age, VKORC1, CYP2C9 and CYP4F2 genotypes (all P < 0.001). First VKORC1, and second, CYP2C9 SNPs played a strong effect by determining extreme doses, particularly in p95. Only one out of 203 p95 had the VKORC1 A-1639A genotype, but this subject was CYP2C9*1/*1. In contrast, nine out of 83 p5 carried the VKORC1 G-1639G genotype, although six of them were CYP2C9*3 homozygotes and another two were heterozygotes. Surprisingly, CYP4F2 V433M SNP displayed prevalences that suggest that its influence might only be evident when patients are treated with high doses., Conclusion: Two clinical data, age and BSA, and three SNPs in the VKORC1, CYP2C9 and CYP4F2 genes strongly predict outlier patients treated with acenocoumarol.

The VKORC1 c.-1639G>A and CYP2C9 c.430C>T and c.1075A>C polymorphisms have been associated with increased sensitivity to oral anticoagulants. However, their role in gastrointestinal bleeding is unknown. We studied the risk of gastrointestinal bleeding associated with these polymorphisms, and how this risk was influenced by the anticoagulant dose and the use of common drugs. Eighty-nine patients with gastrointestinal bleeding during acenocoumarol therapy and 177 patients free of bleeding during acenocoumarol therapy were studied. None of the three polymorphisms constituted a serious gastrointestinal bleeding risk factor. However, patients bearing at least one of these polymorphisms were at high risk, when they simultaneously met one of the following conditions: a weekly dose of acenocoumarol higher than 15 mg [adjusted Odds Ratio (OR) (95% confidence interval (CI) = 4.19 (1.59-11.04)]; amiodarone use [adjusted OR (95% CI) = 9.97 (1.75-56.89)]; or aspirin use [adjusted OR (95% CI) = 8.97 (1.66-48.34)]. The consumption of statins was associated with a lower risk of gastrointestinal bleeding [adjusted OR = 0.50 (0.26-0.99)]. The risk of gastrointestinal bleeding during acenocoumarol therapy in carriers of any of the studied polymorphisms is severely increased with exposure to weekly doses of acenocoumarol higher than 15 mg or the use of amiodarone or aspirin.

Much of the variability in the sensitivity to warfarin in anticoagulated patients is associated with the c.-1639G > A polymorphism of the vitamin K-epoxide reductase (VKORC1) gene. However, its association with the acenocoumarol dose in patients under anticoagulant therapy has not been studied. The c.-1639G > A genotype of VKORC1 was determined in 113 patients on stable anticoagulation requiring low (n = 42), medium (n = 42) or high (n = 21) acenocoumarol doses. To evaluate the association between acenocoumarol requirements and the c.-1639G > A variant, multivariate logistic regression models were fitted, adjusting for age, gender, and the c.430C > T and c.1075A > C variants of cytochrome P450 2C9 (CYP2C9). A total of 90.5% of the patients in the low acenocoumarol dose group carried the A allele of VKORC1:c.-1639G > A. The A allele independently increased the odds of requiring a low acenocoumarol dose [odds ratio (OR) 9.4; 95% confidence interval (CI) 1.9-46.4; P = 0.006], especially when the homozygous form was present (OR 44.2; 95% CI 5.5-354.6; P < 0.001). The A allele was less frequent in the high dose group showing an inverse association with the requirement for high doses (OR 0.04; 95% CI 0.01-0.22; P < 0.001). The A allele of the c.-1639G > A polymorphism of VKORC1 is therefore associated with a low-dose requirement for acenocoumarol in patients receiving anticoagulant therapy.

The 2C9*3 and 2C9*2 polymorphisms of cytochrome P-450 CYP2C9 are associated with hypersensitivity to warfarin and bleeding. The effect of these polymorphisms on sensitivity to acenocoumarol is unknown. Three groups of patients, with low, medium, or high acenocoumarol-dose requirements, were studied. Age influenced the acenocoumarol sensitivity. Bearing the 2C9*3 allele was associated with the need for a lower acenocoumarol dose (odds ratio [OR], 6.02; 95% confidence interval [CI], 1.50-24.18); 80% of carriers of the 2C9*3 allele required a low dose. The 2C9*2 allele was associated with a lower acenocoumarol-dose requirement (OR, 2.70; 95% CI, 1.11-6.58) because of a reduced risk of the need for a high acenocoumarol dose (4.8% of the patients in the high-dose group carried the 2C9*2 allele versus 34.1% and 30.2%, respectively, in the medium-dose and low-dose groups). Therefore, carriers of 2C9*3 may need a low initial loading dose of acenocoumarol. Because acenocoumarol sensitivity with the 2C9*2 variant does not seem to be clinically relevant, the drug could be an alternative to warfarin in 2C9*2 carriers.

Human endothelial cells synthesize and secrete a variety of molecules involved in fibrinolysis and coagulation. The effects of a low molecular weight heparin, Bemiparin, and unfractionated heparin (UFH) were compared on plasminogen activator inhibitor-1 (PAI-1), tissue-plasminogen activator (t-PA), tissue factor (TF), tissue factor pathway inhibitor (TFPI) release, and PAI-1 gene expression by human umbilical vein endothelial cells (HUVEC). Cell cultures were supplemented with Bemiparin or UFH at 1 or 10 U/mL. Culture media samples were obtained before the addition of the drugs and 2, 6, and 24 hours afterward to measure the antigen levels of TF, TFPI, t-PA, and PAI-1. RNA was obtained to study the endothelial expression of PAI-1 by reverse transcriptase-polymerase chain reaction (RT-PCR). Bemiparin at 1 U/mL resulted in a decreased messenger RNA (mRNA) PAI-1 expression, which remained unaltered when UFH had been added. PAI-1 levels increased after the cultures had been supplemented with either Bemiparin or UFH at both doses. UFH induced an increase in t-PA either at 1 or 10 U/mL. Both doses of UFH, but not Bemiparin, induced an important increase in TF secretion. An increase in the TFPI levels was seen with UFH at 1 U/mL. The decrease in PAI-1 gene expression observed with a therapeutic dose of Bemiparin might confer this drug interesting profibrinolytic properties. The fact that Bemiparin, in contrast with UFH, does not induce an increase in TF could give this drug another positive feature.

Purpose: To analyse the possible correlation between the plasma levels of the extrinsic pathway inhibitor (TFPI) in patients with infection along with two cytokines mediating in the action of bacterial endotoxin on the vascular endothelium, namely, tumour factor (TNF) and interleukin-1 (IL-1)., Patients and Methods: Twenty-five patients with infection, none of them showing septic shock or disseminated intravascular coagulation, were studied. Plasma TFPI concentration was assessed by a chromogenic substrate technique; TNF was determined with immunoradiometric methods and IL-1 was estimated with ELISA. The results were compared with those of a group of 25 healthy subjects matched for age and sex., Results: Positive blood cultures were found in 15 of the 25 patients (60%), 12 due to gram-negative and 3 to gram-positive germs. A significant increase of TFPI (p < 0.004), TNF and IL-1 (p < 0.001) was found in infection patients with respect to the control subjects. No significant correlation between TFPI and TNF or IL-1 was found., Conclusion: Increased TFPI, unrelated to cytokines, is present in patients with sepsis.