The optimal intensity of vitamin k antagonists in patients with mechanical heart valves A meta-analysis

AbstractObjectivesThe purpose of this study was to compare two different intensities of vitamin K antagonists (VKA) among patients with mechanical heart valves using meta-analytic techniques.BackgroundPatients with mechanical heart valves are at increased risk for valve thrombosis and systemic embolism, which can be reduced by VKA. The range of optimal intensity of VKA is still a matter of debate.MethodsA computerized search in the PubMed database was made for relevant articles. A meta-analysis was performed of all eligible studies with data on the incidences of thromboembolic and bleeding complications in patients with mechanical heart valve prostheses during different intensities of VKA therapy. The studies were classified into low-intensity VKA therapy (mean target international normalized ratio [INR] of 3.0 or lower) or high-intensity VKA therapy (mean target INR above 3.0).ResultsThirty-five eligible studies were identified, including in total 23,145 patients, who were studied for 108,792 patient-years. For patients with an aortic valve, high intensity resulted in a lower incidence of thromboembolic events (risk ratio [RR] = 0.73, p < 0.0001); however, the incidence of bleeding was increased (RR = 1.23, p < 0.0001). In the mitral valve group, the incidence rate for thromboembolism was lower in the high-intensity group (RR = 0.74, p < 0.0001), without a significantly increased bleeding incidence (RR = 1.08, p = 0.0524). The total number of thromboembolic and bleeding events was decreased in the high-intensity group compared with low-intensity VKA therapy for both aortic and mitral valve prostheses (RR = 0.94 [p = 0.0067] and 0.84 [p < 0.0001]), respectively.ConclusionsThis meta-analysis shows that both aortic and mitral valves will benefit from a treatment strategy with a target INR higher than 3.0

Recombinant human activated protein C resets thrombin generation in patients with severe sepsis – a case control study

INTRODUCTION: Recombinant human activated protein C (rhAPC) is the first drug for which a reduction of mortality in severe sepsis has been demonstrated. However, the mechanism by which this reduction in mortality is achieved is still not clearly defined. The aim of the present study was to evaluate the dynamics of the anticoagulant, anti-inflammatory and pro-fibrinolytic action of rhAPC in patients with severe sepsis, by comparing rhAPC-treated patients with case controls. METHODS: In this prospectively designed multicenter case control study, 12 patients who were participating in the ENHANCE study, an open-label study of rhAPC in severe sepsis, were treated intravenously with rhAPC at a constant rate of 24 μg/kg/h for a total of 96 h. Twelve controls with severe sepsis matching the inclusion criteria received standard therapy. The treatment was started within 48 h after the onset of organ failure. Blood samples were taken before the start of the infusion and at 4, 8, 24, 48, 96 and 168 h, for determination of parameters of coagulation and inflammation. RESULTS: Sepsis-induced thrombin generation as measured by thrombin-antithrombin complexes and prothrombin fragment F1+2, was reset by rhAPC within the first 8 h of infusion. The administration of rhAPC did not influence parameters of fibrinolysis and inflammation. There was no difference in outcome or occurrence of serious adverse events between the treatment group and the control group. CONCLUSION: Sepsis-induced thrombin generation in severely septic patients is reset by rhAPC within the first 8 h of infusion without influencing parameters of fibrinolysis and inflammation

Influenza infection and risk of acute pulmonary embolism

<p>Abstract</p> <p>Background</p> <p>Influenza infections have been associated with procoagulant changes. Whether influenza infections lead to an increased risk of pulmonary embolism remains to be established.</p> <p>Methods</p> <p>We conducted a nested case control study in a large cohort of patients with a clinical suspicion of having pulmonary embolism. Blood samples were collected to investigate the presence of influenza A and B by complement fixation assay (CFA). We compared case patients, in whom pulmonary embolism was proven (n = 102), to controls, in whom pulmonary embolism was excluded (n = 395). Furthermore, we compared symptoms of influenza-like illness in both patient groups 2 weeks prior to inclusion in the study, using the influenza-like illness (ILI) score, which is based on a questionnaire. We calculated the risk of pulmonary embolism associated with influenza infection.</p> <p>Results</p> <p>The percentage of patients with influenza A was higher in the control group compared to the case group (4.3% versus 1.0%, respectively, odds ratio 0.22; 95% CI: 0.03–1.72). Influenza B was not detectable in any of the cases and was found in 3 of the 395 controls (0.8%). The ILI score was positive in 24% of the cases and 25% in the control persons (odds ratio 1.16, 95% CI: 0.67–2.01). We did not observe an association between the ILI score and proven influenza infection.</p> <p>Conclusion</p> <p>In this clinical study, influenza infection was not associated with an increased risk of acute pulmonary embolism. The ILI score is non-specific in this clinical setting.</p

Dutch orthopedic thromboprophylaxis: a 5-year follow-up survey

Background and purpose Previous surveys in the Netherlands have revealed that guidelines regarding orthopedic thromboprophylaxis were not followed and that a wide variation in protocols exists. This survey was performed to assess the current use of thromboprophylactic modalities and to compare it with the results of a previous survey

Potential of an age adjusted D-dimer cut-off value to improve the exclusion of pulmonary embolism in older patients: a retrospective analysis of three large cohorts

Objectives In older patients, the the D-dimer test for pulmonary embolism has reduced specificity and is therefore less useful. In this study a new, age dependent cut-off value for the test was devised and its usefulness with older patients assessed

A C1173T Dimorphism in the VKORC1 Gene Determines Coumarin Sensitivity and Bleeding Risk

BACKGROUND: A C1173T polymorphism in intron 1 of the VKORC1 gene has been claimed to determine the interindividual variability in the response to vitamin K antagonist therapy (VKA), but it is unknown whether it also influences bleeding risk. We aimed to confirm the relationship between C1173T status and phenprocoumon or acenocoumarol use, and to examine the risk of severe bleeding for the various genotypes. METHODS AND FINDINGS: We studied this in a case-control study of 110 patients who bled during VKA therapy and 220 control patients free of bleeding under the same therapy. To achieve the same target INR, CT genotype and TT genotype control patients required less phenprocoumon (CC genotype 2.9 mg/d [95% confidence interval (CI): 2.6–3.2], CT genotype 2.6 mg/d [95% CI: 2.1–3.1], TT genotype 1.4 mg/d [95 % CI: 1.1–1.7]) or acenocoumarol (CC genotype 3.2 mg/d [95% CI: 2.9–3.5], CT genotype 2.3 mg/d [95% CI: 2.1–2.5], TT genotype 1.7 mg/d [95% CI: 1.3–2.1]) than CC genotype control patients. Compared with CC genotype individuals, carriers of at least one T allele had an increased risk of bleeding in the phenprocoumon users (crude odds ratio = 2.6, 95% CI: 1.2–5.7), but not in acenocoumarol users (crude odds ratio = 1.2, 95% CI: 0.6–2.3). CONCLUSION: These findings encourage taking further steps towards the evaluation of the use of VKORC1 genetic testing for bleeding prevention in individuals who receive VKA therapy

The Absolute Risk of Venous Thrombosis after Air Travel: A Cohort Study of 8,755 Employees of International Organisations

In a cohort study of 8,755 employees of large international organizations followed for 38,910 person-years, Suzanne Cannegieter and colleagues find a risk of one thrombosis per 4,656 long-haul flights

Noacs replace VKA as preferred oral anticoagulant among new patients

Background: In 2012, around 400,000 patients in the Netherlands were treated with vitamin K antagonists (VKA) for thromboembolic diseases. Since 2011, non-VKA oral anticoagulants (NOACs) have been available. NOACs do not require frequent INR monitoring and cause less bleeding, which benefits patients, but also imposes a risk of reduced therapy adherence. Objectives: The objective of this study is to describe uptake of and patient compliance with NOACs in The Netherlands between July 2011 and October 2016. Methods: We analysed prescription data for 247.927 NOAC and/or VKA patients across 560 pharmacies. All patients who received at least one prescription of either VKA or NOACs between 1 July 2011 and 30 September 2016 were included in the study. Our database contained (not exhaustive) the following information about the prescriptions: dispensed medication and quantity, dispensing date, prescribed dosage and prescriber type, patient age and gender. We used these data to describe patient profiles, uptake of NOACs among new naïve patients and switch of patients between VKA and NOACs. We developed an algorithm to classify patients as new naïve starters, switcher or repeat patients. We calculated therapy compliance as the percentage of days covered (PDC). To obtain reliable results, in our PDC calculations we included only patients with a time period of at least 12 months between their first and last prescription. Results: During the studied period the share of NOACs in oral anticoagulants has grown to 57% of prescriptions to new patients. More than 70% of new NOAC users were new naïve patients and around 26% switched from VKA. The overall share of NOACs among starters is largest in the group of patients of 50-80 years. Calculated percentages of days covered (PDC) for NOAC patients show that 87% of all users were compliant. Conclusions: NOACs have overtaken VKA as the major treatment prescribed to patients starting on oral anticoagulants, and the number of starters on VKA is at present decreasing. We expect that almost all oral anticoagulants prescribed to new patients will be NOACs. NOAC users are in general compliant with therapy. This may provide additional confidence to physicians in prescribing NOACs instead of VKAs