NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma.

OBJECTIVE: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated death worldwide. As a first-line drug for advanced HCC treatment, lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients, and the underlying mechanism remains largely unknown. The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC, explore the potential molecular mechanism, and propose combinatorial therapeutic targets for HCC management. METHODS: Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol. RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant (LR) cells. The upregulated genes were analyzed by GO and KEGG analyses. Then, qPCR and Western blotting were employed to determine the relative gene expression levels. Afterwards, the intracellular reactive oxygen species (ROS) and apoptosis were detected by flow cytometry. RESULTS: PLC-LR and Hep3B-LR were established. There was a total of 116 significantly upregulated genes common to both LR cell lines. The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities, and reactive oxygen species pathways. Notably, NAD(P)H:quinone oxidoreductase 1 (NQO1) was highly expressed in LR cells, and was involved in the lenvatinib resistance. The high expression of NQO1 decreased the production of ROS induced by lenvatinib, and subsequently suppressed the apoptosis. The combination of lenvatinib and NQO1 inhibitor, dicoumarol, reversed the resistance of LR cells. CONCLUSION: The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels, thereby promoting lenvatinib resistance in HCC cells.

ATP-releasing SWELL1 channel in spinal microglia contributes to neuropathic pain.

Following peripheral nerve injury, extracellular adenosine 5'-triphosphate (ATP)-mediated purinergic signaling is crucial for spinal cord microglia activation and neuropathic pain. However, the mechanisms of ATP release remain poorly understood. Here, we show that volume-regulated anion channel (VRAC) is an ATP-releasing channel and is activated by inflammatory mediator sphingosine-1-phosphate (S1P) in microglia. Mice with microglia-specific deletion of Swell1 (also known as Lrrc8a), a VRAC essential subunit, had reduced peripheral nerve injury-induced increase in extracellular ATP in spinal cord. The mutant mice also exhibited decreased spinal microgliosis, dorsal horn neuronal hyperactivity, and both evoked and spontaneous neuropathic pain-like behaviors. We further performed high-throughput screens and identified an FDA-approved drug dicumarol as a novel and potent VRAC inhibitor. Intrathecal administration of dicumarol alleviated nerve injury-induced mechanical allodynia in mice. Our findings suggest that ATP-releasing VRAC in microglia is a key spinal cord determinant of neuropathic pain and a potential therapeutic target for this debilitating disease.

Sustained Release of Dicumarol via Novel Grafted Polymer in Electrospun Nanofiber Membrane for Treatment of Peritendinous Adhesion.

The prevention and treatment of post-traumatic peritendinous adhesion (PA) have always been a great difficulty for orthopedic surgeons. Current treatments include resecting surgery, non-steroidal anti-inflammatory drugs (NSAIDs) usage and implantable membranes, often target single disease pathogenic processes, resulting in unfavorable therapeutic outcomes. Here a polylactic acid (PLA)-dicumarol conjugates-electrospun nanofiber membrane (ENM) (PCD) is generated, which can achieve spatial accuracy and temporal sustainability in drug release. It is further demonstrated that PCD possesses a significantly higher and more sustainable drug release profile than traditional drug-loading ENM. By providing a physical barrier and continuous releasing of dicumarol, PCD implantation significantly reduces tissue adhesion by 25%, decreases fibroblasts activity and inhibits key fibrogenic cytokine transforming growth factor beta (TGFß) production by 30%, and improves the biomechanical tendon property by 14.69%. Mechanistically, PCD potently inhibits the connexin43 (Cx43) and thereby tunes down the fibroblastic TGFß/Smad3 signaling pathway. Thus, this approach leverages the anti-adhesion effect of dicumarol and drug release properties of grafted copolymer ENM by esters to provide a promising therapeutic strategy for patients who suffer from PA.

Structure-based screening and biological validation of the anti-thrombotic drug-dicoumarol as a novel and potent PPARγ-modulating ligand.

PPARγ full agonists, thiazolidinediones (TZDs), have been known as a class of most effective drugs for the treatment of type 2 diabetes mellitus (T2DM). However, recently their therapeutic benefits have been compromised by several undesirable side effects. In this study, a host-based repurposing strategy and in combination with comprehensive biological evaluations were synergistically employed to seek for potent PPARγ ligands, which led to the identification of an anti-thrombotic drug, dicoumarol (Dic), as the novel and safer selectively PPARγ modulator (SPPARγM) with advantages over current TZD drugs. The results in vitro showed that Dic had a potent binding affinity and weakly agonistic activity for PPARγ and its downstream key genes. Moreover, in diabetic model, it significantly reduced blood glucose without leading to the weight gain of both body and main organ tissues. Further mechanistic investigations revealed that Dic possessed such desired pharmacological properties mainly through effectively inhibiting the phosphorylation of PPARγ-Ser273 and selectively regulating the expressions of insulin-sensitive and resistance genes. Finally, the docking studies on the analysis of the potent binding mode of Dic with PPARγ revealed a remarkable difference on interaction region compared with other developed PPARγ agonists, which not only gave a proof of concept for the abovementioned mechanism but also provided the molecular basis for the discrimination of Dic from other PPARγ ligands, especially TZD drugs. Taken together, our findings suggested that Dic could serve as a new and promising candidate with good therapeutic index for treating T2DM, especially for those T2DM patients with thrombosis.

A pharmacological review of dicoumarol: An old natural anticoagulant agent.

Dicoumarol is an oral anticoagulant agent prescribed in clinical for decades. It is a natural hydroxycoumarin discovered from the spoilage of Melilotus officinalis (L.) Pall and is originally discovered as a rodenticide. Due to its structural similarity to that of vitamin K, it significantly inhibits vitamin K epoxide reductase and acts as a vitamin K antagonist. Dicoumarol is mainly used as an anticoagulant to prevent thrombogenesis and to cure vascular thrombosis. Other biological activities besides anticoagulants such as anticancer, antimicrobial, antiviral, etc., have also been documented. The side effects of dicoumarol raise safety concerns for clinical application. In this review, the physicochemical property, the pharmacological activities, the side effects, and the pharmacokinetics of dicoumarol were summarized, aiming to provide a whole picture of the "old" anticoagulant.

Inhibition of pyruvate dehydrogenase kinase­1 by dicoumarol enhances the sensitivity of hepatocellular carcinoma cells to oxaliplatin via metabolic reprogramming.

The Warburg effect is a unique metabolic feature of the majority of tumor cells and is closely related to chemotherapeutic resistance. Pyruvate dehydrogenase kinase 1 (PDK1) is considered a 'switch' that controls the fate of pyruvate in glucose metabolism. However, to date, to the best of our knowledge, there are only a few studies to available which had studied the reduction of chemotherapeutic resistance via the metabolic reprogramming of tumor cells with PDK1 as a target. In the present study, it was found dicoumarol (DIC) reduced the phosphorylation of pyruvate dehydrogenase (PDH) by inhibiting the activity of PDK1, which converted the metabolism of human hepatocellular carcinoma (HCC) cells to oxidative phosphorylation, leading to an increase in mitochondrial reactive oxygen species ROS (mtROS) and a decrease in mitochondrial membrane potential (MMP), thereby increasing the apoptosis induced by oxaliplatin (OXA). Furthermore, the present study elucidated that the targeting of PDK1 may be a potential strategy for targeting metabolism in the chemotherapy of HCC. In addition, DIC as an 'old drug' exhibits novel efficacy, bringing new hope for antitumor therapy.

Impact of atrial fibrillation in critically ill patients admitted to a stepdown unit.

BACKGROUND: Limited data are available on the clinical course of patients with history of atrial fibrillation (AF) when admitted in an intensive care environment. We aimed to describe the occurrence of major adverse events in AF patients admitted to a stepdown care unit (SDU) and to analyse clinical factors associated with outcomes, impact of dicumarolic oral anticoagulant (OAC) therapy impact and performance of clinical risk scores in this setting. MATERIALS AND METHODS: Single-centre, observational retrospective analysis on a population of subjects with AF history admitted to a SDU. Therapeutic failure (composite of transfer to ICU or death) was considered the main study outcome. Occurrence of stroke and major bleeding (MH) was considered as secondary outcomes. The performance of clinical risk scores was evaluated. RESULTS: A total of 1430 consecutive patients were enrolled. 194 (13.6%) reported the main outcome. Using multivariate logistic regression, age (odds ratio [OR]: 1.03, 95% confidence interval [CI]: 1.01-1.05), acute coronary syndrome (OR:3.10, 95% CI: 1.88-5.12), cardiogenic shock (OR:10.06, 95% CI: 5.37-18.84), septic shock (OR:5.19,95%CI:3.29-18.84), acute respiratory failure (OR:2.49, 95% CI: 1.67-3.64) and OAC use (OR: 1.61, 95% CI: 1.02-2.55) were independently associated with main outcome. OAC prescription was associated with stroke risk reduction and to both MH and main outcome risk increase. CHA2 DS2 -VASc (c-index: 0.545, P = .117 for stroke) and HAS-BLED (c-index:0.503, P = .900 for MH) did not significantly predict events occurrence. CONCLUSIONS: In critically ill AF patients admitted to a SDU, adverse outcomes are highly prevalent. OAC use is associated to an increased risk of therapeutic failure, clinical scores seem unhelpful in predicting stroke and MH, suggesting a highly individualized approach in AF management in this setting.

Advanced Drug-Eluting Poly (Vinyl Chloride) Surfaces Deposited by Spin Coating.

Background and objectives: Medical devices such as catheters are used on a large scale to treat heart and cardiovascular diseases. Unfortunately, they present some important drawbacks (structure failure, calcifications, infections, thrombosis, etc.), with the main side effects occurring due to adhesion and proliferation of bacteria and living cells on the surface of the implanted devices. The aim of this work is to modify the surface of polyvinyl chloride (PVC), an affordable biocompatible material, in order to reduce these aforementioned side effects. Materials and Methods: The surface of PVC was modified by depositing a thin layer also of PVC that incorporates an active substance, dicoumarol (a well-known anticoagulant), by spin coating process. The modified surfaces were analyzed by Fourier-transform infrared (FT-IR) microscopy, Fourier-transform infrared (FT-IR) spectroscopy, Ultraviolet-visible spectroscopy (UV-VIS), and Scanning electron microscopy (SEM) in order to determine the surface morphology and behavior. The samples were tested for Gram-positive (S. aureus ATCC 25923) and Gram-negative (P. aeruginosa ATCC 27853) standard strains from American Type Culture Collection (ATCC). Results: The material obtained had a smooth surface with a uniform distribution of dicoumarol, which is released depending on the deposition parameters. The concentration of dicoumarol at the surface of the material and also the release rate is important for the applications for which the surface modification was designed. PVC modified using the proposed method showed a good ability to prevent salt deposition and decreased the protein adhesion, and the resistance to bacterial adherence was improved compared with standard PVC.

Periodontal and biochemical bone metabolism assessment on a chronic oral anticoagulation population treated with dicoumarins

BACKGROUND: The aim is to evaluate periodontal alteration and biochemical markers associated with bone turnover in chronic oral with dicoumarins anticoagulant treatment patients. MATERIAL AND METHODS: 80 patients treated with oral anticoagulants were divided into 2 cohort: Group A (n = 36) 6 month to 1 year with anticoagulant treatment and Group B (n = 44) > 2 years with anticoagulant treatment. Clinical evaluation included: Clinical attachment level (CAL), plaque index (PI) and gingival index (GI). Analytically biochemical parameters of bone remodeling (calcium and phosphorus), formation (total acid phosphatase, alkaline phosphatase and osteocalcin) and resorption (tartrate-resistant acid phosphatase and beta-crosslaps) were evaluated. RESULTS: High values of PI (67-100%) especially in men and in Group B were observed. Men with anticoagulation treatment length showed an increased GI (49.167 vs 78.083) while Group B women showed a decreased GI in comparison with Group A (59.389 vs 42.120). Women presented a greater average CAL than men as well as Group B vs Group A but without statistical significance. All biochemical markers were decreased respect to values of general population. Osteocalcin in Group B women showed a statistically significant outcome vs Group A (p = 0.004). Acid phosphatase (total and tartrate-resistant) has a slight increase in Group B women versus Group A, and Beta-crosslap showed lower values in Group A men than Group B and slightly lower in Group A women versus Group B, without statistical significance. CONCLUSIONS: Patients showed a slight to moderate degree of periodontal affectation, especially gingivitis related to bacterial plaque. Periodontal disorders tended to be more severe in Group B. While bone remodeling showed an overall decrease with greater affectation of bone neoformation phenomena, bone destruction tended to recover and normalize in time

Percepción de los médicos sobre los factores que influyen en la elección de un dicumarínico o de un nuevo anticoagulante oral en pacientes con fibrilación auricular no valvular / Perception of physicians on factors that influence the choice of a dicoumarin or a new oral anticoagulant in patients with non-valvular atrial fibrillation

OBJETIVO: Estudios recientes han demostrado la eficacia y la seguridad de los nuevos anticoagulantes orales (NACO) en la prevención de tromboembolias en pacientes con fibrilación auricular no valvular (FANV). Nuestro objetivo es evaluar qué factores influyen en los médicos para elegir entre dicumarínicos o NACO. DISEÑO: Se analizaron distintas variables, que fueron discutidas y puntuadas siguiendo una metodología Workmat®. EMPLAZAMIENTO: Se realizaron 6 reuniones regionales en España (Levante, Cataluña, Andalucía Extremadura, Madrid, Noroeste y Norte de España). PARTICIPANTES: Participaron 39 especialistas (cardiólogos, neurólogos, hematólogos, internistas y médicos de urgencias y atención primaria). Mediciones: Cada participante puntuó de 1 a 10 (de menor a mayor) el grado de acuerdo con cada variable analizada. RESULTADOS: Se elegiría preferiblemente un NACO en pacientes con fracaso previo del tratamiento dicumarínico (9,7 ± 0,5), riesgo hemorrágico elevado (8,7 ± 1), antecedentes de hemorragia (7,8 ± 1,5) y riesgo trombótico alto (7,7 ± 1,2). Se decantarían por un dicumarínico en casos de disfunción renal grave (1,2 ± 0,4) o moderada (4,2 ± 2,5), buen control con dicumarínicos (2,3 ± 1,5), deterioro cognitivo (3,2 ± 3) y riesgo hemorrágico bajo (4,3 ± 3). La edad, el sexo, el peso, el coste del fármaco, la polimedicación y la existencia de un riesgo trombótico bajo obtuvieron puntuaciones intermedias. CONCLUSIONES: El riesgo trombótico y hemorrágico elevado y el fracaso del tratamiento previo con dicumarínicos predisponen a elegir un NACO. La insuficiencia renal, el deterioro cognitivo, el buen control con dicumarínicos y un riesgo hemorrágico bajo inclinan a decantarse por un dicumarínico clásico

AIMS: Recent studies have demonstrated the efficacy and safety of new oral anticoagulant drugs for the prevention of thromboembolic events in patients with non-valvular atrial fibrillation. Our aim was to evaluate the factors that can influence physicians in their choice between a classic and a new anticoagulant in these patients. DESIGN: Several variables of interest were discussed and analysed using a WorkmatTM methodology. Sites: Six regional meetings were held in Spain (East, Catalonia, Andalusia-Extremadura, Madrid, North-east, and North of Spain). PARTICIPANTS: Meetings were attended by 39 specialists (cardiologists, neurologists, haematologists, internists, and emergency and Primary Care physicians). Measurements: Each participant graded their level of agreement, with a score from 1 to 10, on every analysed variable. RESULTS: A new anticoagulant drug was preferred in patients with previous failure of dicoumarin therapy (9.7 ± 0.5), high haemorrhagic risk (8.7 ± 1), prior bleeding (7.8 ± 1.5), and high thrombotic risk (7.7 ± 1.2). Dicoumarins were preferred in cases of severe (1.2 ± 0.4) or moderate (4.2 ± 2.5) kidney failure, good control with dicoumarins (2.3°æ 1.5), cognitive impairment (3.2 ± 3), and low haemorrhagic risk (4.3 ± 3). Age, sex, weight, cost of drug, polymedication, and low thrombotic risk achieved intermediate scores. There were no differences between the different specialists or Spanish regions. CONCLUSIONS: The presence of a high thrombotic or haemorrhagic risk and the failure of previous dicoumarin therapy lead to choosing a new oral anticoagulant in patients with non-valvular atrial fibrillation, while kidney failure, cognitive impairment, good control with dicoumarins, and a low bleeding risk predispose to selecting a classic dicoumarin anticoagulant

Targeting PSG1 to enhance chemotherapeutic efficacy: new application for anti-coagulant the dicumarol.

Chemotherapeutic response is critical for the successful treatment and good prognosis in cancer patients. In this study, we analysed the gene expression profiles of preoperative samples from oestrogen receptor (ER)-negative breast cancer patients with different responses to taxane-anthracycline-based (TA-based) chemotherapy, and identified a group of genes that was predictive. Pregnancy specific beta-1-glycoprotein 1 (PSG1) played a central role within signalling pathways of these genes. Inhibiting PSG1 can effectively reduce chemoresistance via a transforming growth factor-ß (TGF-ß)-related pathway in ER-negative breast cancer cells. Drug screening then identified dicumarol (DCM) to target the PSG1 and inhibit chemoresistance to TA-based chemotherapy in vitro, in vivo, and in clinical samples. Taken together, this study highlights PSG1 as an important mediator of chemoresistance, whose effect could be diminished by DCM.

[Perception of physicians on factors that influence the choice of a dicoumarin or a new oral anticoagulant in patients with non-valvular atrial fibrillation]. / Percepción de los médicos sobre los factores que influyen en la elección de un dicumarínico o de un nuevo anticoagulante oral en pacientes con fibrilación auricular no valvular.

AIMS: Recent studies have demonstrated the efficacy and safety of new oral anticoagulant drugs for the prevention of thromboembolic events in patients with non-valvular atrial fibrillation. Our aim was to evaluate the factors that can influence physicians in their choice between a classic and a new anticoagulant in these patients. DESIGN: Several variables of interest were discussed and analysed using a WorkmatTM methodology. SITES: Six regional meetings were held in Spain (East, Catalonia, Andalusia-Extremadura, Madrid, North-east, and North of Spain). PARTICIPANTS: Meetings were attended by 39 specialists (cardiologists, neurologists, haematologists, internists, and emergency and Primary Care physicians). MEASUREMENTS: Each participant graded their level of agreement, with a score from 1 to 10, on every analysed variable. RESULTS: A new anticoagulant drug was preferred in patients with previous failure of dicoumarin therapy (9.7±0.5), high haemorrhagic risk (8.7±1), prior bleeding (7.8±1.5), and high thrombotic risk (7.7±1.2). Dicoumarins were preferred in cases of severe (1.2±0.4) or moderate (4.2±2.5) kidney failure, good control with dicoumarins (2.3±1.5), cognitive impairment (3.2±3), and low haemorrhagic risk (4.3±3). Age, sex, weight, cost of drug, polymedication, and low thrombotic risk achieved intermediate scores. There were no differences between the different specialists or Spanish regions. CONCLUSIONS: The presence of a high thrombotic or haemorrhagic risk and the failure of previous dicoumarin therapy lead to choosing a new oral anticoagulant in patients with non-valvular atrial fibrillation, while kidney failure, cognitive impairment, good control with dicoumarins, and a low bleeding risk predispose to selecting a classic dicoumarin anticoagulant.

Calidad de vida de los pacientes tratados con dicumarínicos / Quality of life of patients treated with cumarins

No disponible

Respuesta: Calidad de vida de los pacientes tratados con dicumarínicos / Reply: Quality of life of patients treated with cumarins

No disponible

[Fournier's disease. Clinical case]. / La malattia di Fournier. Caso clinico.

Fournier's disease is a necrotizing fasciitis that prefers the male and which is located in the perineal area. In view of possible complications related to sepsis, systemic organ impairment and high mortality, is now considered a urological emergency. The main causes are infections of urethral and anorectal tract, immunodepression syndromes, diabetes mellitus and trauma. Infections are mixed with aerobic and anaerobic germs responsible of necrosis of tissue disorders due to the phenomena of necrotizing immunovasculitis disease. We present a case of Fournier's disease in perineal area, with gangrenosum necrotic evolution treated with antibiotic therapy, curettage of the necrotic tissue and local disinfection with saline and antiseptics solution. A total parenteral nutrition to ensure maximum perineal decontamination has been made. The extensive loss of substance scrotal was rebuilt in 25- day while the anal wound has healed spontaneously after complete surgical curettage.

Volumetric capnography: in the diagnostic work-up of chronic thromboembolic disease.

The morbidity and mortality of pulmonary embolism (PE) have been found to be related to early diagnosis and appropriate treatment. The examinations used to diagnose PE are expensive and not always easily accessible. These options include noninvasive examinations, such as clinical pretests, ELISA D-dimer (DD) tests, and volumetric capnography (VCap). We report the case of a patient whose diagnosis of PE was made via pulmonary arteriography. The clinical pretest revealed a moderate probability of the patient having PE, and the DD result was negative; however, the VCap associated with arterial blood gases result was positive. The patient underwent all noninvasive exams following admission to hospital and again eight months after discharge. Results gained from invasive tests were similar to those produced by image exams, highlighting the importance of VCap as an important noninvasive tool.

[Monitoring age-dependent effect of anticoagulation treatment in patients with atrial fibrillation]. / Sledování ucinnosti antikoagulacní lécby u nemocných s fibrilací síní v závislosti na veku.

Oral anticoagulation treatment with dicumarol preparations (warfarin sodium) is the standard in patients with atrial fibrillation. The effect of treatment depends on many factors, especially in elderly patients. In the study, we assessed the effect of treatment in patients with atrial fibrillation hospitalized in our cardiology ward from 2004 to 2005, in the form of a telephone survey (who controlled the treatment--general practitioner or internist?, the last 2 INR results, complications). INR 2.0-3.5 is considered an efficient therapeutic range. The proportion of permanently correctly anticoagulated patients is approximately 47% across the whole age range, the hypothesis of lower efficiency of treatment in elderly patients does not apply (48% of efficiently anticoagulated patients younger than 75 years vs. 46% of older patients--however, the study does not include polymorbid patients who could not take warfarin at all!) The fact whether a patient is monitored by a general practitioner or an outpatient specialist does not make any difference (49% of anticoagulated patients monitored by a general practitioner vs. 52% of patients monitored by an internist). The percentage of severe complications is relatively low (3.4%).

Indicaciones actuales del tratamiento con heparinas / Present indications of heparin treatment

Las últimas guías sobre tratamiento de la enfermedad tromboembólica venosa recomiendan el uso de heparina no fraccionada (HNF) o de bajo peso molecular (HBPM). En el caso de trombosis venosa profunda en pacientes ambulatorios se prefiere la HBPM, asociada a dicumarínicos desde el primer día. En cuanto a profilaxis, en pacientes quirúrgicos se recomienda la administración de HNF o HBPM en pacientes de moderado a alto riesgo, pero no en pacientes sometidos a cirugía menor, menores de 40 años y sin otros factores de riesgo. En los pacientes con síndrome coronario agudo sin elevación del ST se recomienda la administración de HBPM a dosis fijas junto con antiagregantes plaquetarios. En los pacientes con isquemia cerebral aguda y sin criterios para tratamiento trombolítico no se aconseja el tratamiento con heparina, sino la administración de antiagregantes plaquetarios

The last guidelines on treatment of venous thromboembolic disease recommend the use of unfractionated heparin (UFH) or low molecular weight heparin (LMWH). In the case of deep venous thrombosis in out-patients, LMWH is preferred, associated to dicumarinics from the first day. In regards to prophylaxis, administration of UFH or LMWH is recommended in surgical patients of moderate to high risk but not in those undergoing minor surgery, under 40 years and without other risk factors. In patients with acute coronary syndrome without ST elevation, the administration of LMWH at fixed doses together with platelet antiaggregants is recommended. In patients with acute cerebral ischemia and without other criteria for thrombolytic treatment, treatment with heparin is not recommended but rather the administration of platelet antiaggregants

Mechanical valve replacement in congenital heart defects in the era of international normalized ratio self-management.

As the number of patients with congenital heart defects requiring heart valve replacement increases, the need for durable valve substitutes with good hemodynamic performance and a low incidence of complications becomes more apparent. The use of porcine xenografts is burdened with early fibrocalcific degeneration, whereas the use of mechanical heart valves led to an increased number of thromboembolic events, especially when implanted in the right side of the heart. We report on our experiences implanting bileaflet heart valves in congenital heart defects since the introduction of international normalized ratio (INR) self-management. The data of 68 long-term survivors (33 males, 35 females) who underwent mechanical heart valve replacement in congenital heart defect were reviewed. Patient age at the time of valve replacement ranged from 5 months to 61 years (mean 21 years). Underlying diagnoses were tetralogy of Fallot (n=33), morbus Ebstein (n=4), atrioventricular canal (n=13), truncus arteriosus communis (n=5), transposition of the great arteries (n=10), and congenitally corrected transposition of the great arteries (n=3). In all patients, bileaflet valves were implanted (St. Jude Medical n=40, Carbomedics n=28). Anticoagulation was performed using dicumarol (Marcumar) and INR self-management in all cases. The mean follow-up was 72 months (range 6-132 months; 409 patient-years). Valve thrombosis developed in 3 of 68 patients (4.4%, all three had tetralogy of Fallot, mean age 9.8 years) after a mean follow-up of 3.5 years. In two of these three patients, re-pulmonary valve replacement was necessary, whereas the third patient was treated by thrombolysis. From our experience, we conclude that mechanical heart valve replacement is a good therapy option with a low complication rate for patients with congenital heart defects requiring valve replacement, especially when INR self-management is performed.