Edoxaban versus Vitamin K Antagonist for Atrial Fibrillation after TAVR

BACKGROUND

The role of direct oral anticoagulants as compared with vitamin K antagonists for atrial fibrillation after successful transcatheter aortic-valve replacement (TAVR) has not been well studied.

METHODS

We conducted a multicenter, prospective, randomized, open-label, adjudicator-masked trial comparing edoxaban with vitamin K antagonists in patients with prevalent or incident atrial fibrillation as the indication for oral anticoagulation after successful TAVR. The primary efficacy outcome was a composite of adverse events consisting of death from any cause, myocardial infarction, ischemic stroke, systemic thromboembolism, valve thrombosis, or major bleeding. The primary safety outcome was major bleeding. On the basis of a hierarchical testing plan, the primary efficacy and safety outcomes were tested sequentially for noninferiority, with noninferiority of edoxaban established if the upper boundary of the 95% confidence interval for the hazard ratio did not exceed 1.38. Superiority testing of edoxaban for efficacy would follow if noninferiority and superiority were established for major bleeding.

RESULTS

A total of 1426 patients were enrolled (713 in each group). The mean age of the patients was 82.1 years, and 47.5% of the patients were women. Almost all the patients had atrial fibrillation before TAVR. The rate of the composite primary efficacy outcome was 17.3 per 100 person-years in the edoxaban group and 16.5 per 100 person-years in the vitamin K antagonist group (hazard ratio, 1.05; 95% confidence interval [CI], 0.85 to 1.31; P = 0.01 for noninferiority). Rates of major bleeding were 9.7 per 100 person-years and 7.0 per 100 person-years, respectively (hazard ratio, 1.40; 95% CI, 1.03 to 1.91; P = 0.93 for noninferiority); the difference between groups was mainly due to more gastrointestinal bleeding with edoxaban. Rates of death from any cause or stroke were 10.0 per 100 person-years in the edoxaban group and 11.7 per 100 person-years in the vitamin K antagonist group (hazard ratio, 0.85; 95% CI, 0.66 to 1.11).

CONCLUSIONS

In patients with mainly prevalent atrial fibrillation who underwent successful TAVR, edoxaban was noninferior to vitamin K antagonists as determined by a hazard ratio margin of 38% for a composite primary outcome of adverse clinical events. The incidence of major bleeding was higher with edoxaban than with vitamin K antagonists. (Funded by Daiichi Sankyo; ENVISAGE-TAVI AF ClinicalTrials.gov number, NCT02943785.).

Hepatic and Vascular Vitamin K Status in Patients with High Cardiovascular Risk

Vitamin K dependent proteins (VKDP), such as hepatic coagulation factors and vascular matrix Gla protein (MGP), play key roles in maintaining physiological functions. Vitamin K deficiency results in inactive VKDP and is strongly linked to vascular calcification (VC), one of the major risk factors for cardiovascular morbidity and mortality. In this study we investigated how two vitamin K surrogate markers, dephosphorylated-undercarboxylated MGP (dp-ucMGP) and protein induced by vitamin K absence II (PIVKA-II), reflect vitamin K status in patients on hemodialysis or with calcific uremic arteriolopathy (CUA) and patients with atrial fibrillation or aortic valve stenosis. Through inter- and intra-cohort comparisons, we assessed the influence of vitamin K antagonist (VKA) use, vitamin K supplementation and disease etiology on vitamin K status, as well as the correlation between both markers. Overall, VKA therapy was associated with 8.5-fold higher PIVKA-II (0.25 to 2.03 AU/mL) and 3-fold higher dp-ucMGP (843 to 2642 pM) levels. In the absence of VKA use, non-renal patients with established VC have dp-ucMGP levels similar to controls (460 vs. 380 pM), while in HD and CUA patients, levels were strongly elevated (977 pM). Vitamin K supplementation significantly reduced dp-ucMGP levels within 12 months (440 to 221 pM). Overall, PIVKA-II and dp-ucMGP showed only weak correlation (r2 ≤ 0.26) and distinct distribution pattern in renal and non-renal patients. In conclusion, VKA use exacerbated vitamin K deficiency across all etiologies, while vitamin K supplementation resulted in a vascular VKDP status better than that of the general population. Weak correlation of vitamin K biomarkers calls for thoughtful selection lead by the research question. Vitamin K status in non-renal deficient patients was not anomalous and may question the role of vitamin K deficiency in the pathogenesis of VC in these patients.

Diagnosing and treating antiphospholipid syndrome: a consensus paper

INTRODUCTION

The antiphospholipid syndrome (APS) is defined by the occurrence of venous and/or arterial thrombosis and/or pregnancy-related morbidity, combined with the presence of antiphospholipid antibodies (aPL) and/or a lupus anticoagulant (LAC). Large, controlled, intervention trials in APS are limited. This paper aims to provide clinicians with an expert consensus on the management of APS.

METHODS

Relevant papers were identified by literature search. Statements on diagnostics and treatment were extracted. During two consensus meetings, statements were discussed, followed by a Delphi procedure. Subsequently, a final paper was written.

RESULTS

Diagnosis of APS includes the combination of thrombotic events and presence of aPL. Risk stratification on an individual base remains challenging. 'Triple positive' patients have highest risk of recurrent thrombosis. aPL titres > 99th percentile should be considered positive. No gold standard exists for aPL testing; guidance on assay characteristics as formulated by the International Society on Thrombosis and Haemostasis should be followed. Treatment with vitamin K-antagonists (VKA) with INR 2.0-3.0 is first-line treatment for a first or recurrent APS-related venous thrombotic event. Patients with first arterial thrombosis should be treated with clopidogrel or VKA with target INR 2.0-3.0. Treatment with direct oral anticoagulants is not recommended. Patients with catastrophic APS, recurrent thrombotic events or recurrent pregnancy morbidity should be referred to an expert centre.

CONCLUSION

This consensus paper fills the gap between evidence-based medicine and daily clinical practice for the care of APS patients.

Epidemiology of thromboembolic and hemorrhagic events in patients with atrial fibrillation under anti-vitamin K

BACKGROUND

Atrial fibrillation is the most common heart rhythm disorder in the general population. It is associated with increased cardiovascular morbidity and mortality. Given this risk, anticoagulant therapy is vital.

AIM

To estimate the incidence of thromboembolic and hemorrhagic events in patients with Atrial fibrillation and treated by oral anticoagulant in a cardiology department.

METHODS

We carried out an observational longitudinal study over a period of three years (January 2013 - December 2015) in the external consultation of cardiology of Farhat Hached hospital of Sousse. Pre-established individual records were used as a source and tool for data collection.

RESULTS

Overall, 200 patients were eligible. Forty-nine percent had valvular atrial fibrillation. After an average follow-up of 2.6 years, 15 thromboembolic events were noted affecting 13 patients (6.5%), with an incidence of 2.8%. We found a significant association between TTR <50% and the occurrence of stroke and transient ischemic events. Half of the patients had minor bleeding and 9.5% had major bleeding, with an incidence of 3.6%. No significant correlation between these accidents and the TTR was found. In addition, 9.5% of patients were hospitalized for international normalized ratio equilibration. They were mainly patients with valvular atrial fibrillation (72%) (p = 0.002).

CONCLUSION

Anticoagulant therapy with anti-vitamin-K remains the most adequate treatment. Thus, a well-conducted treatment ensures a reduction in thromboembolic risk and minimizes the occurrence of hemorrhages inherent to this therapy. Therefore, an assessment of the quality of anticoagulation is essential.

Evaluation of patients' knowledge on their vitamin K antagonist treatment

INTRODUCTION

Vitamin K antagonists (VKA) are currently the most prescribed oral anticoagulant treatment in Tunisia. Despite the standardization of biological monitoring and the better definition of therapeutic objectives, their side effects are a frequent reason for hospitalization.

AIM

To evaluate patients' knowledge about their VKA treatment.

METHODS

We realized a cross-sectional descriptive study in the Cardiology Department of HabibThameur Hospital from September to October 2016. A questionnaire consisting of 14 items was used in a semi-directed interview in order to assess patients' knowledge on their VKA treatment.

RESULTS

Our study included one hundred patients. Mean age was 61 ± 12 years and sex ratio of 1.8. Forty-eight per cent were illiterate. The median duration of AVK intake was 5 years. Atrial fibrillation (AF) was the most frequent indication (57%). Eighty percent of patients had more than five correct answers on the eight items of knowledge: VKA's name (96%), tablet description (93%), dose (99%), time (94%), VKA's effect (70%), INR (56%), treatment's risk (49%) and the target INR (20%). Twenty-two percent had more than four correct answers on the 6 items of know-how: what to do in case of haemorrhage (70%), what to do in case of oblivion (45%), interactions precautions to be observed with food (13%), activities advised against (49%) and medical procedures advised against (27%). In multivariate analysis, only prior VKA information was significantly associated with a better knowledge of VKA (p = 0.027).

CONCLUSION

Our patients' knowledge on their VKA treatment was insufficient to ensure the safety and efficacy of treatment. The creation of a therapeutic education program on is therefore necessary to reduce the iatrogenic risk of this treatment.

[Stroke prevention in patients with atrial fibrillation]

Oral anticoagulation with vitamin K antagonists (VKA) was the cornerstone of stroke prevention in atrial fibrillation (AF). This review article presents the state of the art, with regard to the treatment options developed over the past few years, the new oral anticoagulants (NOAC). A search in PubMed for relevant published studies has been performed. Dabigatran and apixaban were superior to warfarin to reduce stroke risk or systemic embolism ; dabigatran, rivaroxaban and edoxaban were non-inferior. All NOAC are globally non-inferior to warfarin for stroke prevention in non-valvular AF and they have a superior safety profile, with a reduced intracranial bleeding risk. They are now the first choice for treatment.

[Non valvular atrial fibrillation: the place of the new anticoagulants]

Atrial fibrillation (AF) increases the risk of mortality and stroke. The prevention of these complications is based on oral anticoagulants that are more efficient than salycilates. As compared with antivitamins K agents, new oral anticoagulants are promising for patients presenting non valvular atrial fibrillation because of lower cerebral hemorragic risk (with respect of assessment of renal function and therapeutic compliance). Available studies and recommendations are presented.

Economic evaluation of apixaban for the prevention of stroke in non-valvular atrial fibrillation in the Netherlands

BACKGROUND

Stroke prevention is the main goal of treating patients with atrial fibrillation (AF). Vitamin-K antagonists (VKAs) present an effective treatment in stroke prevention, however, the risk of bleeding and the requirement for regular coagulation monitoring are limiting their use. Apixaban is a novel oral anticoagulant associated with significantly lower hazard rates for stroke, major bleedings and treatment discontinuations, compared to VKAs.

OBJECTIVE

To estimate the cost-effectiveness of apixaban compared to VKAs in non-valvular AF patients in the Netherlands.

METHODS

Previously published lifetime Markov model using efficacy data from the ARISTOTLE and the AVERROES trial was modified to reflect the use of oral anticoagulants in the Netherlands. Dutch specific costs, baseline population stroke risk and coagulation monitoring levels were incorporated. Univariate, probabilistic sensitivity and scenario analyses on the impact of different coagulation monitoring levels were performed on the incremental cost-effectiveness ratio (ICER).

RESULTS

Treatment with apixaban compared to VKAs resulted in an ICER of €10,576 per quality adjusted life year (QALY). Those findings correspond with lower number of strokes and bleedings associated with the use of apixaban compared to VKAs. Univariate sensitivity analyses revealed model sensitivity to the absolute stroke risk with apixaban and treatment discontinuations risks with apixaban and VKAs. The probability that apixaban is cost-effective at a willingness-to-pay threshold of €20,000/QALY was 68%. Results of the scenario analyses on the impact of different coagulation monitoring levels were quite robust.

CONCLUSIONS

In patients with non-valvular AF, apixaban is likely to be a cost-effective alternative to VKAs in the Netherlands.

[Prescription and follow-up of antithrombotic treatment with vitamin K antagonists]

The indications for antithrombotic treatment with vitamin K antagonists are now relatively precise, but management of this treatment is often difficult in clinical practice and be set by problems such as unstable hypocoagulability, an increased bleeding risk, interactions with other therapies and pathologies, and high-level vitamin K intake in the diet. Rigorous and accurate information of the patient and family, along with regular and frequent control of the international normalized ratio (INR), are essential for the safety and efficacy of this treatment. Some physicians cite an excessive bleeding risk as one reason for withholding oral anticoagulation therapy from older patients with atrial fibrillation. Indeed, with the increasing aging of the population, and poor therapeutic observance, there is an increased risk of hemorragic adverse effects. However, vitamin K antagonists are associated with a significant reduction in embolic events, and recent guidelines recommend their prescription for elderly patients with atrial fibrillation. Their impact on the risk of thromboembolic events is well documented, with better results than those obtained with new oral anticoagulants. Education of the patient and family, and close cooperation between the patient, family, physician and entire medical team, are essential for the safety and efficacy of this treatment.

Positive selection in the chromosome 16 VKORC1 genomic region has contributed to the variability of anticoagulant response in humans

VKORC1 (vitamin K epoxide reductase complex subunit 1, 16p11.2) is the main genetic determinant of human response to oral anticoagulants of antivitamin K type (AVK). This gene was recently suggested to be a putative target of positive selection in East Asian populations. In this study, we genotyped the HGDP-CEPH Panel for six VKORC1 SNPs and downloaded chromosome 16 genotypes from the HGDP-CEPH database in order to characterize the geographic distribution of footprints of positive selection within and around this locus. A unique VKORC1 haplotype carrying the promoter mutation associated with AVK sensitivity showed especially high frequencies in all the 17 HGDP-CEPH East Asian population samples. VKORC1 and 24 neighboring genes were found to lie in a 505 kb region of strong linkage disequilibrium in these populations. Patterns of allele frequency differentiation and haplotype structure suggest that this genomic region has been submitted to a near complete selective sweep in all East Asian populations and only in this geographic area. The most extreme scores of the different selection tests are found within a smaller 45 kb region that contains VKORC1 and three other genes (BCKDK, MYST1 (KAT8), and PRSS8) with different functions. Because of the strong linkage disequilibrium, it is not possible to determine if VKORC1 or one of the three other genes is the target of this strong positive selection that could explain present-day differences among human populations in AVK dose requirement. Our results show that the extended region surrounding a presumable single target of positive selection should be analyzed for genetic variation in a wide range of genetically diverse populations in order to account for other neighboring and confounding selective events and the hitchhiking effect.

[Local haemostasis with an adhesive cyanoacrylate-coated membrane following tooth extraction in patients under anticoagulant or anti-platelet therapy]

OBJECTIVE

Assessment of a local hemostasis with a compressive, extemporaneous gutter glued to the alveolar crest after tooth avulsion in patients under anticoagulant and/or platelet aggregation inhibitors, and economical impact of this technique.

MATERIAL AND METHOD

Ninety-seven tooth extractions were performed in patients under AVK and/or anti-platelet drugs. The interventions were consecutive and concerned 251 teeth (138 different alveolar sites). The extraction alveolus was protected by an absorbable oxycellulose membrane coated with sterilized cyanoacrylate adhesive for medical use. This procedure was used with all patients, whatever the hemorrhagic risk (the only inclusion criterion was INR less than 4 for patients under AVK). All procedures were performed under local anesthesia.

RESULTS

There was one hemorrhagic complication (0.72%) due to mechanical gutter destruction by an antagonist tooth. The adhesive did not run, there was no tissue necrosis, and no wound infection requiring gutter removal.

DISCUSSION

This local hemostasis procedure is reliable. It may be an alternative to substitution of heparin, without or with hospitalization. This procedure, requiring modification of treatment, greatly decreases healthcare costs. Contra-indications include the presence of an antagonist tooth harmful for the gutter, and patients with impaired consciousness or tongue dyspraxia.

[Is the use of vitamin K antagonists harmful in patients with CDK?]

As chronic kidney disease (CKD) is a contraindication to the use of the new anticoagulants, the vitamin K antagonists (VKA) are still valid in patients with CKD, though their use may be harmful. During overanticoagulation, some patients can develop acute kidney injury (AKI), especially those with CKD, by obstruction of the renal tubules and Bowman's spaces by erythrocytes. In addition, VKA increase atherogenesis through vitamin K deficiency, which is essential for the carboxylation of proteins that inhibit calcification of vessels. Eventually, hemodialysed patients under VKA have an increased risk of stroke, especially those over 75 years of age. Therefore anticoagulation with VKA in patients with CKD should be carefully implemented and its monitoring more frequent than in non-CKD patients.

Theoretical, spectral characterization and antineoplastic activity of new lanthanide complexes

The new cerium(III), lanthanum(III) and neodymium(III) complexes were synthesized in view of their application as cytotoxic agents. The complexes were characterized by different physicochemical methods: elemental analysis, mass spectrometry, (1)H NMR, (13)C NMR and IR spectroscopy. The spectra of the complexes were interpreted on the basis of comparison with the spectrum of the free ligand. The vibrational analysis showed that in the complexes the ligand coordinates to the metal ion through both deprotonated hydroxyl groups, however participation of the carbonyl groups in the coordination to the metal ion was also suggested. Geometry optimization of 3,3'-(ortho-pyridinomethylene)di-[4-hydroxycoumarin] H(2)(o-pyhc), (H(2)L) and its dianionic forms, o-pyhc(2-), (L(2-)) were carried out at AM1 and PM3 levels as well as using density functional theory with Becke's three parameter hybrid method and correlation functional of Lee, Yang and Parr (B3LYP) with 6-31G(d) basis set. The optimized geometries of the neutral ligand isomers were stabilized by two asymmetrical intramolecular O-H...O hydrogen bonds (HBs). The conformational search showed four low-energy dianionic species (o-pyhc(2-)) on the potential energy surface. Molecular electrostatic potential calculations showed that the most preferred sites for electrophilic attack in H(2)(o-pyhc) and o-pyhc(2-) are the carbonyl oxygen atoms. The evaluation of the cytotoxic activity of the novel lantanide complexes on HL-60 myeloid cells revealed, that they are potent cytotoxic agents. The cerium complex was found to exhibit superior activity in comparison to the lanthanum, and neodymium species, the latter being the least active. Taken together our data give us a reason to conclude that the newly synthesized lanthanide complexes should be a subset to further more detailed pharmacological and toxicological evaluation.

Superwarfarin poisoning: a report of two cases and review of the literature

Superwarfarins are anticoagulant rodenticides similar to warfarin, but which have various substituted phenyl groups replacing the terminal methyl group, resulting in a fat-soluble, long-acting anticoagulant that is nearly 100 times more potent than the parent compound. Since their development, many accidental and intentional cases of consumption have been reported. We describe two cases of consumption, one related to unknown etiology, and the other related to utilization of the superwarfarin to potentiate a drug of abuse. The clinical manifestations including bleeding symptoms and abnormal coagulation assays are discussed. The differential diagnosis is quite broad, and includes all causes of vitamin K deficiency, factor deficiency or inhibitor, disseminated intravascular coagulation (DIC), and liver disease. Differentiating superwarfarin ingestion from the other causes can be quite difficult, but extremely important, as management requires prolonged administration of vitamin K. Other treatment options are discussed as well including, fresh frozen plasma (FFP), and recombinant factor VIIa. Finally, the significance of "lacing" drugs of abuse with superwarfarin to potentiate their effect is discussed, as well as the complications that could develop from such a habit.

[Tooth extraction and anticoagulants]

INTRODUCTION

The purpose of this study was to show the possibility of extracting teeth without modifying the anticoagulant treatment (anti-platelet and anti-vitamin K agents).

MATERIAL AND METHOD

Two hundred patients underwent dental extraction from May 2003 to July 2006 without modifying their anticoagulant treatment; only 137 of them were hospitalized. Most of the teeth were extracted under local anesthesia, and hemostatic pad were inserted in the sockets without suture.

RESULTS

One thousand (and) sixteen extractions were performed with bleeding disorders in 4%, successfully resolved by using local hemostatics.

DISCUSSION

Modifying an anticoagulant treatment is a thrombo-embolic complication risk factor. Performing tooth extraction according to our protocol decreases this risk and bleeding complications, thus proving the validity of our technique.

[Risk stratification in atrial and ventricular arrhythmias]

Atrial fibrillation, the most frequent arrhythmia, has a growing incidence with increasing age and the most important complication of the disease is thromboembolic events that may be prevented by antivitamin K. They are the most efficient therapeutic class for the prevention of these events but they are associated with an increased haemorrhagic risk leading to a reduced prescription in general practice. Optimisation of the management should be based on an individual evaluation of the thromboembolic and haemorrhagic risks, taking into account age, the presence of an associated heart disease, hypertension, diabetes, history of cerebrovascular event, history of previous haemorrhagic event and the ability to achieve a stable target INR. The challenge in ventricular arrhythmias lies in identifying a high risk of sudden death, mainly related to ventricular fibrillation. In patients with structural heart disease, left ventricular dysfunction is the strongest predictor of sudden death. Non invasive markers such as non sustained ventricular tachycardia, late ventricular potentials, decreased heart rate variability and baroreflex sensitivity, and repolarization altemans are further elements to assess risk. However, most of these markers have a poor positive predictive value and a low specificity. In patients with normal hearts, genetic predisposition may in the future identify high risk patients. The electrophysiologic study with programmed ventricular stimulation remains a costly and invasive method and only has a strong positive predictive value in ischemic cardiomyopathy. More precise algorithms for risk stratification are thus needed that may help the strategy of therapy with prophylactic implantable cardioverter defibrillator in the future.

Antineoplastic activity of new lanthanide (cerium, lanthanum and neodymium) complex compounds

Cerium (III), lanthanum (III) and neodymium (III) complexes with 3,3'-benzylidenebis[4-hydroxycoumarin] were synthesized in view of their application as cytotoxic agents. The complexes were characterized by different physicochemical methods: elemental analysis, mass spectrometry, 1H NMR, 13C NMR and IR spectroscopy. The spectra of the complexes were interpreted on the basis of comparison with the spectrum of the free ligand. The vibrational analysis showed that in the complexes the ligand coordinated to the metal ion through both deprotonated hydroxyl groups; however, participation of the carbonyl groups in the coordination to the metal ion was also suggested. The evaluation of the cytotoxic activity of the novel lanthanide complexes on HL-60 myeloid cells revealed that they are potent cytotoxic agents. The cerium complex was found to exhibit superior activity in comparison to the lanthanum and neodymium coordination compounds, the latter being the least active. Our data give us reason to conclude that the newly synthesized lanthanide complexes should be submitted to further more detailed pharmacological and toxicological evaluation.

[Syncumar induced toxic liver damage]

The authors present a case of chronic hepatitis presumably due to Syncumar treatment. The patient should be maintained on anticoagulant therapy due to combined prosthetic valve insertion. Chromatin activation of blood lymphocytes was investigated to justify the drug induced liver injury. In this test system Syncumar and other anticoagulant derivates gave a positive reaction to a different extent. The increased serum bilirubin and transaminase levels, which indicated liver injury showed regression in the course of the treatment and after changing Syncumar to Marcoumar (Phenprocoumon).

[How long should antithrombotic therapy be continued following aortocoronary bypass surgery?]

In a prospective randomized trial the effect of prolonged antithrombotic treatment with anticoagulants or antiplatelet drugs (50 mg aspirin + 400 mg dipyridamole daily) on late bypass-graft occlusion was studied. After 3 months active treatment was replaced by placebo in half of the patients. Between the angiographic checkups 2 weeks and 12 months postoperatively, 28/330 (8%) new graft occlusions had occurred on continued therapy, versus 44/319 (14%) on placebo (p = 0.03). This difference was most pronounced in individual grafts (6% vs 12%, p = 0.01), so that fewer patients with 12 months' active therapy had at least one occluded graft (22% versus 32%, p = 0.08). These findings suggest that antithrombotic treatment should not be halted 3 months after CABG surgery but should be continued for at least one year and possibly longer.

Increased tissue-plasminogen activator (t-PA) levels in patients under oral anticoagulant therapy

The fibrinolytic system was investigated in 30 patients under oral anticoagulant therapy, and in 23 control patients not receiving oral anticoagulants. Patients under oral anticoagulant therapy had significantly higher tissue-plasminogen activator (t-PA) antigen levels than patients in the control group. Mean t-PA levels before venous occlusion were 18.4 ng/ml in the anticoagulated patients vs. 7.9 ng/ml in the control patients (p less than 0.001). After venous occlusion for 10 minutes, t-PA levels were 45.0 ng/ml in the anticoagulated patients and 24.2 ng/ml in the control patients (p less than 0.01). Plasminogen activator inhibitor (PAI) capacity was not significantly different in the two groups before venous occlusion (VO) but differed slightly (p less than 0.05) after VO. The net decrease in euglobulin lysis time (ELT) after venous occlusion (= ELT before VO - ELT after VO), indicating the relative potency of the fibrinolytic activity in blood, was also significantly higher in the anticoagulated patients (median 240 min vs. 125 min, p less than 0.001). These data indicate that oral anticoagulant therapy increases the fibrinolytic activity in blood, and thus may have an additional therapeutic effect in addition to anticoagulation.

Decreased serum osteocalcin levels in phenprocoumon-treated patients

Osteocalcin (OC) is a noncollagenous bone matrix protein containing gamma-carboxyglutamic acid, the synthesis of which is vitamin K dependent. Serum OC levels are generally believed to reflect the de novo synthesis of OC by osteoblasts and thus reflect bone formation. We measured serum OC levels by RIA in 48 patients receiving phenprocoumon anticoagulant treatment, which inhibits the posttranscriptional synthesis of gamma-carboxyglutamic acid, and in 22 matched normal subjects. The median serum OC level in the patients receiving phenprocoumon therapy was significantly lower than that in the normal subjects (P less than 0.0001). In 27 patients receiving anticoagulant therapy and in 21 normal subjects the proportion of noncarboxylated OC to total OC also was determined. The proportion of OC that was noncarboxylated was significantly higher in the patients receiving phenprocoumon therapy than in the normal subjects (P less than 0.0001). We conclude that OC carboxylation is impaired in patients receiving oral anticoagulant therapy. The decreased total OC levels in patients receiving phenprocoumon treatment might result from decreased bone formation, although these patients do not have symptoms of bone disease.

Thromboembolism in patients with prosthetic heart valves. An adequately controlled intense anticoagulant therapy and its influence on the occurrence of thromboembolism in relation to valve type

This study was designed to evaluate the efficacy of carefully controlled treatment with oral anticoagulants in patients with different mechanical heart valve prostheses. One hundred eighty-one patients with various types of prosthetic valves (mitral 89, aortic 87, combined 5) received oral anticoagulation aiming at Thrombotest (TT) values between 5% and 12%. Median follow-up was 46 months; 80.8% of all TT determinations were below 12%. The thromboembolic rate was 0.25%/year in patients with aortic valve replacement (AVR) and 4.87%/year in patients with mitral valve replacement (MVR). There was a strikingly lower incidence of thromboembolism with newer types of valves (Björk-Shiley convex-concave) in the mitral position under exactly the same intensity and stability of anticoagulant treatment. Clinically overt valve occlusion could be almost completely prevented (0.12%/year) in prostheses at both sites. Severe hemorrhage occurred at a rate of 1.71%/year and fatal bleeding at a rate of 0.37%/year. Our results indicate that carefully controlled anticoagulation is effective in the reduction of thromboembolic complications at a reasonable risk of bleeding.

Prevention of arterial and pulmonary embolism by oral anticoagulants in patients with dilated cardiomyopathy

The incidence of arterial embolism (AE) and pulmonary embolism (PE) during treatment with oral anticoagulants (OA) or without OA therapy was studied in 38 patients with dilated cardiomyopathy (DCMP). AE/PE occurred in 17 patients (44.7%) before initiation of OA treatment. The severity of DCMP was a risk factor for AE/PE, but not the presence of atrial fibrillation or intracardial thrombi. No AE/PE episodes occurred during the period of OA therapy. No major bleeding complications were seen, probably due to the moderate intensity of OA therapy (therapeutic range 5-15% Thrombotest [TT], 2.1-4.8 International Normalized Ratio [INR], median TT value 11%, median INR 2.6). Recurrence of AE was observed in 4 of 5 patients in whom treatment with OA had been discontinued.

[Severe hereditary protein C deficiency in a newborn infant with fulminant purpura--successful treatment with phenprocoumon]

A newborn baby was born with scrotal hematoma and a diagnosis of testicular torsion was made. This diagnosis proved false, when the hematoma was resorbed after a few days and other hematomas developed instead (abdomen, elbow, foot, scalp). A total of nine hemorrhagic episodes were observed, most of them occurring on the scalp. All lesions were sharply delineated, started with red to purple discoloration and then turned to bluish-black indicating gangrene. Histology revealed extensive bleeding into the corium, fibrin thrombi within the capillaries, and complement and IgG in the small arterial walls. Each bleeding was associated with hypofibrinogenemia and thrombocytopenia. A diagnosis of hereditary protein C deficiency was made. Blood levels were consistent with heterozygosity of both the parents and homozygosity of the child. Bleedings were controlled by Cohn fraction I and heparin. It was impossible, however, to prevent further hemorrhage by continuous i.v. heparin. In addition aprotinin, epsilon-aminocaproic acid, AT III, and prednisone were ineffective. Continuous remission finally could be sustained with oral phenprocoumon.

[Improved flow through aortocoronary venous bypasses after anticoagulant therapy. A prospective randomized study]

To evaluate the effect of oral anticoagulant therapy on graft patency rate during the first 2 months after bypass surgery 174 patients were randomly assigned to treatment with phenprocoumon (89) or to a control group (85) starting on day 7 after bypass surgery. Until day 7 all patients received low dose heparin. There was no significant difference between the two groups with respect to age, sex distribution, number of vessels diseased, left ventricular enddiastolic pressure, preoperative exercise tolerance or number of grafts constructed per patient. All patients underwent angiographic evaluation 8 weeks after bypass surgery. Graft patency rate was 90.4% in the treatment group versus 83.6% in the control group (p less than 0.015). None of the grafts with a flow rate of greater than 90 ml/min was occluded 8 weeks after surgery. Oral anticoagulation improved the patency rate of grafts with a flow of less then 90 ml/min.

Measurement of fibrinopeptide A in patients treated with phenprocoumon

Fibrinopeptide A (FPA), which is considered to be a quantitative indicator for the thrombin activity in vivo, was measured in 136 patients treated with phenprocoumon in order to obtain information on the effectiveness of the inhibition of the coagulation system. The results show a decrease of the FPA concentration in relation to the efficacy of the anticoagulant therapy as measured by the thrombotest coagulation method (p less than 0.01). However, elevated FPA was observed even under an effective oral anticoagulation. These data indicate that an increased thrombin activity cannot be completely prevented by oral anticoagulants in every patient. Combined measurement of FPA and the thrombotest coagulation methods might be used to detect patients with an elevated risk of recurrent thromboembolism despite treatment with phenprocoumon.

The German-Austrian aspirin trial: a comparison of acetylsalicylic acid, placebo and phenprocoumon in secondary prevention of myocardial infarction. On behalf of the German-Austrian Study Group

In a multicenter clinical trial on the prevention of recurrent myocardial infarction, 946 patients who had survived a myocardial infarction for 30-42 days were randomly allocated to acetylsalicylic acid (ASA, 1.5 g/day) (317 patients), placebo (309 patients) or phenprocoumon treatment (320 patients) and were followed to determine the incidence of total mortality, coronary death and nonfatal recurrent myocardial infarction. The ASA and placebo groups were treated in double-blind fashion. The observation period for each patient was 2 years. Total mortality was lower in the ASA group (27 patients) than in the placebo (32 patients) and phenprocoumon groups (39 patients). There were 13 coronary deaths (fatal myocardial infarction and sudden death) in the ASA group, 22 in the placebo group and 26 in the phenprocoumon group. This represents a reduction rate of 42.3% in the ASA group compared with placebo (p less than 0.1) and of 46.3% in the ASA group with phenprocoumon (p approximately 0.07). Considering male patients alone, the difference regarding coronary death is significant between ASA vs placebo (p less than 0.05, reduction rate 56.4%) and ASA vs phenprocoumon (p less than 0.05, reduction rate 55.6%). Coronary events (coronary death and nonfatal recurrent myocardial infarctions) were lower in the ASA group (24 events) than in the placebo (37 events) (p less than 0.07) or phenprocoumon group (32 events).

Secondary prevention of myocardial infarction: a comparison of acetylsalicylic acid, placebo and phenprocoumon

A multicenter clinical trial on the prevention of recurrent myocardial infarction was started in 1970 and continued until March 1977. 946 patients who had survived a myocardial infarction for 30–42 days were randomly allocated in equal proportions to acetylsalicylic acid (ASA, 1.5 g/day) (317 patients), placebo (309 patients) or phenprocoumon treatment (320 patients) and followed to determine the incidence of total mortality, coronary death and nonfatal recurrent myocardial infarction. The ASA and placebo groups were treated double-blind. The observation period for each patient was 2 years. The outcome at 24 months has been established for 231 patients on ASA, for 215 on placebo and for 233 on phenprocoumon treatment. Total mortality was lower in the ASA group (27 patients) than in the placebo (32 patients) and phenprocoumon group (39 patients). These differences are not statistically significant. Coronary deaths (fatal myocardial infarction and sudden death) were 13 in the ASA, 22 in the placebo- and 26 in the phenprocoumon group. This represents a reduction rate of 42.3% in the ASA group compared with placebo (p > 0.1) and of 46.3% in the ASA group compared with phenprocoumon (p < 0.07). Considering male patients alone, the difference regarding coronary death is significant between ASA versus placebo (p < 0.05) and ASA versus phenprocoumon (p < 0.05). Coronary events (coronary death and non-fatal recurrent myocardial infarction) were lower in the ASA group (24 patients) than in the placebo (37 patients) (p < 0.06) or phenprocoumon groups (32 patients). Gastrointestinal discomfort, with or without hermorrhage, was more frequent in the ASA group than in the placebo or phenprocoumon groups. These results, in combination with similar trends reported in other clinical trials with ASA, suggest that ASA treatment is beneficial in patients who have survived a myocardial infarct.

[Treatment with anticoagulants in glomerulonephritis (author's transl)]

Four patients with different forms of glomerulonephritis were treated with the anticoagulant heparin (Liquemin) or phenprocoumon (Marcumar). Following the results in these cases and the experiences of other research groups, which have been published in the last few years, we have tried to lay down a scheme for treatment with anticoagulants in glomerulonephritis. Such a treatment is recommended in peracute or rapid progressing glomerulonephritis, in forms of the disease of which is known that they have a poor prognosis, and in situations in which the risk of simultaneous thromboembolic complications as a result of a nephrotic syndrome represents a further argument for the use of anticoagulants.

Transient acquired resistance to the coumarin anticoagulants phenprocoumon and acenocoumarol

A 62-year-old man developed resistance to coumarin congeners during treatment with phenprocoumon (Marcoumar) and acenocoumarol (Sintrom), requiring at least triple the usual therapeutic dose and plasma concentration of phenprocoumon for satisfactory anticoagulation. After 8 months on this high dosage, the patient suddenly developed haemorrhagic diathesis. The medication was therefore discontinued. The resistance could not be ascribed to impaired absorption or enhanced metabolism.

Prognosis of prophylactic anticoagulant treatment in ischaemic stroke

Two groups of patients who had a stroke, prolonged reversible ischaemic neurological deficit or transient ischaemic attacks were compared; one group was treated with anticoagulants (phenprocoumon) and a matched control group was treated with other substances. Results showed a similar survival rate in both groups, but significantly fewer recurrences were seen in the surviving patients treated with anticoagulants.

[Effect of naproxen on the thrombocyte bleeding time and on the anticoagulant treatment with phenprocoumon]

With a dose of 250 mg b.i.d. naproxen causes a slight, apparently clinically not relevant alteration of the primary bleeding pattern. Against phenprocoumon, naproxen has a transient hypoprothrombinemic effect which is followed by a short phase of increased tolerance. A further influence on anticoagulant therapy is not shown.

[Thrombocyte aggregation after abdominal hysterectomy with combined prevention of thromboembolism using 6% macrodex and sintrom]

Thrombocyte aggregation was investigated, according to Born, in 14 patients who underwent abdominal hysterectomy due to benign illness. The patients received dextran 60 and 4-hydroxycoumarin as prophylactic therapy for early and late thromboembolism. The following results were obtained: 1. The ability of the thrombocytes to aggregate was reduced by half, 2 hours postoperatively, after administration of dextran 60, and remained at this level during the first postoperative day. This action was independent of the concentration and type of agent used in the aggregation test. The original values were attained again on the 4th postoperative day. The speed and force of desaggregation showed reverse behaviour. 2. Results bore no relationships to the age of the patient. 3. This combined prophylactic therapy with macrodex (500 ml intraoperatively) and sintrom (from the 1st postoperative day) seems to give adequate protection in both the intra- and postoperative risk phases.