Thrombotic events associated with low baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study

ABSTRACT

Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study. Blood was collected 15 to 30 days after starting DOAC treatment in patients with AF who were followed-up for 1 year. Plasma samples were centralized for DOAC level measurement. Patients' DOAC levels were converted into drug/dosage standardized values to allow a pooled analysis in a time-dependent, competitive-risk model. The measured values were transformed into standardized values (representing the distance of each value from the overall mean) by subtracting the DOAC-specific mean value from the original values and dividing by the standard deviation. Trough and peak DOAC levels were assessed in 1657 and 1303 patients, respectively. In total, 21 thrombotic complications were recorded during 1606 years of follow-up (incidence of 1.31% of patients per year). Of 21 thrombotic events, 17 occurred in patients whose standardized activity levels were below the mean of each DOAC (0); the incidence was the highest (4.82% of patients per year) in patients whose standardized values were in the lowest class (-1.00 or less). Early measurement of DOAC levels in patients with AF allowed us to identify most of the patients who, having low baseline DOAC levels, subsequently developed thrombotic complications. Further studies are warranted to assess whether thrombotic complications may be reduced by measuring baseline DOAC levels and modifying treatment when indicated. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

Prevalence of asymptomatic deep vein thrombosis in patients hospitalized with SARS-CoV-2 pneumonia: a cross-sectional study

The association between coronavirus disease 2019 (COVID-19) pneumonia and venous thrombotic disorders is still unclear. We assessed the association between COVID-19 infection-related pneumonia and proximal deep-vein thrombosis (DVT) in a cohort of patients admitted to our hospital during the European outbreak in the front line of Cremona, Lombardy. In a single-center cross-sectional study, all patients hospitalized for more than 5 days in Internal Medicine Department with confirmed COVID-19 pneumonia received 2-point compressive ultrasound assessment (CUS) of the leg vein system during a single day. Ninety-four percent of patients received enoxaparin as standard pharmacological prophylaxis for venous thromboembolism. The presence of DVT was defined as incompressibility of popliteal or common femoral vein. Out of 121 patients with COVID-19 pneumonia (mean age 71.8, 66.3% males) hospitalized on March 31st, 70 stayed in hospital for over 5 days and 66 of them underwent CUS of deep venous system of the legs. The presence of asymptomatic DVT was found in 9 patients (13.6%). No symptomatic DVT was found. Patients with DVT showed mean age = 75.7 years, mean D-dimer levels = 4.02 ng/ml and all of them received enoxaparin for thromboprophylaxis, except one. Computed tomography pulmonary angiogram confirmed pulmonary embolism in five patients. One every seven patients with COVID-19-related pneumonia, hospitalized for more than 5 days, had asymptomatic proximal DVT and half of them had confirmed PE despite standard pharmacological thromboprophylaxis. This observational study suggests the need of an active surveillance through CUS in patients hospitalized with acute SARS-COV-2 and underline the need of a more intense thromboprophylaxis.

Direct oral anticoagulant plasma levels' striking increase in severe COVID-19 respiratory syndrome patients treated with antiviral agents: The Cremona experience

BACKGROUND

Antiviral drugs are administered in patients with severe COVID-19 respiratory syndrome, including those treated with direct oral anticoagulants (DOACs). Concomitant administration of antiviral agents has the potential to increase their plasma concentration. A series of patients managed in the Cremona Thrombosis Center were admitted at Cremona Hospital for SARS-CoV-2 and started antiviral drugs without stopping DOAC therapy. DOAC plasma levels were measured in hospital and results compared with those recorded before hospitalization.

METHODS

All consecutive patients on DOACs were candidates for administration of antiviral agents (lopinavir, ritonavir, or darunavir). Plasma samples for DOAC measurement were collected 2to 4 days after starting antiviral treatment, at 12 hours from the last dose intake in patients on dabigatran and apixaban, and at 24 hours in those on rivaroxaban and edoxaban. For each patient, C-trough DOAC level, expressed as ng/mL, was compared with the one measured before hospitalization.

RESULTS

Of the 1039 patients hospitalized between February 22 and March 15, 2020 with COVID-19 pneumonia and candidates for antiviral therapy, 32 were on treatment with a DOAC. DOAC was stopped in 20 and continued in the remaining 12. On average, C-trough levels were 6.14 times higher during hospitalization than in the pre-hospitalization period.

CONCLUSION

DOAC patients treated with antiviral drugs show an alarming increase in DOAC plasma levels. In order to prevent bleeding complications, we believe that physicians should consider withholding DOACs from patients with SARS-CoV-2 and replacing them with alternative parenteral antithrombotic strategies for as long as antiviral agents are deemed necessary and until discharge.

The effect of management models on thromboembolic and bleeding rates in anticoagulated patients: an ecological study

The primary study objective is to compare the outcomes of patients taking oral anticoagulant medications in two distinct populations treated according to different management models (comprehensive vs. usual care). (Design: regional prospective cohort study; setting: hospital admission data from two regions). Eligible partecipants were patients taking oral anticoagulant drugs (vitamin K antagonist or direct oral anticoagulants), residents in the Vicenza and Cremona districts from February 1st, 2016 to June 30th, 2017. Patients were identified by accessing the administrative databases of patient drug prescriptions. The primary study outcome was admission to the Emergency Department for stroke, systemic arterial embolism, recurrence of venous thromboembolism or major bleeding. The study evaluated outcomes in 14,226 patients taking oral anticoagulants, of whom 6725 being followed in Cremona with a comprehensive management model. There were 19 and 45 thromboembolic events over 6205 and 6530 patient-years in the Cremona and Vicenza cohort, respectively (IRR 0.44, 95% CI 0.24-0.77). The reduction of events in the Cremona cohort was almost entirely explained by a decrease of events in patients taking VKA (IRR 0.41, 95% CI 0.20-0.78) but not DOACs (IRR 1.08, 95% CI 0.25-5.24). The rate of major bleeding was non-significantly higher in Cremona than in Vicenza (IRI 1.32; 95% CI 0.74-2.40). Across the two cohorts, the risk of bleeding was lower in patients being treated with DOACs rather than warfarin (10/4574 vs. 42/8161 event/person-years, respectively, IRR 0.42 95% CI 0.19-0.86). We conclude that a comprehensive management model providing centralized dose prescription and follow-up may significantly reduce the rate of thromboembolic complications, without substantially increasing the number of bleeding complications. Patients treated with direct oral anticoagulants appear to have a rate of thromboembolic complications comparable to VKA patients under the best management model, with a reduction of major bleeding.

Dabigatran Plasma Measurement to Guide the Management of Acute Bleeding and Thrombotic Complications

Oral anticoagulant therapy is recommended for the prevention and treatment of venous thromboembolism and to prevent stroke in non-valvular atrial fibrillation. Until a few years ago, vitamin K antagonists were the only drugs available, but direct oral anticoagulants have recently been introduced into clinical practice for the same clinical indications. Unlike the situation with VKAs, fixed-dose administration was proposed for DOACs, without the necessity for routine laboratory monitoring. However, in clinical practice a high inter-variability in DOAC plasma levels, independently of the type of drug and patient characteristics, was observed and the importance of measuring DOAC anticoagulant activity to support treatment decisions has therefore been recognized. We describe two clinical cases in order to highlight the role and importance of dabigatran-specific measurements to guide patient management in case of major complications.

LEARNING POINT

Direct oral anticoagulants (DOACs) have been used in clinical practice at fixed doses without laboratory monitoring.However, the importance of measuring DOAC anticoagulant activity to support treatment decisions, particularly in emergency conditions, has been recognized.The clinical value of DOAC measurement is highlighted in the two described cases where the anticoagulation level was taken into consideration when deciding on treatment.

[Genetically modified organisms: European and Italian legislation to protect citizens' health]

The development of GM foods and organisms has concentrated everyone's attention on the importance of food safety and on protecting citizens' health, and inevitably influenced healthcare policies regarding food safety. Personal ethical beliefs regarding food and in particular, the consumption of foods derived from biotechnology should be taken into account when deciding healthcare policy.

AIM

The aim of this study was to analyse whether European, Italian and Regional legislation meets basic human rights regarding health and the right to choose, based on the precautionary principle.

METHODS

European and Italian laws regarding the production and marketing of GM foods were analysed and compared to food safety legislation, in order to evaluate how and to what degree existing legislation protects consumers' right to choose. Results show that existing legislation protects consumers from possible foodborne diseases, but the right to informed consent and to free choice is not warranted. Existing laws do not attach enough importance to consumers' right to information; arbitrary threshold levels set for labeling and clauses concerning technical causes allow food businesses to avoid labeling and do not give consumers the possibility of making an informed choice.

Mycotic keratitis in a horse caused by Aspergillus fumigatus. The first reported case in Finland

The first identified Finnish case of equine mycotic keratitis caused by Aspergillus fumigatus is described. The clinical picture, the sampling method, the macro- and micromorphology of the causative fungus and the therapy applied are reported in detail. Therapy with natamycin (Pimafucin 2.5% eyedrops. Gist-Brocades) was successful.

Mycotic keratitis in a horse caused by Aspergillus fumigatus. The first reported case in Finland

The first identified Finnish case of equine mycotic keratitis caused by Aspergillus fumigatus is described. The clinical picture, the sampling method, the macro- and micromorphology of the causative fungus and the therapy applied are reported in detail. Therapy with natamycin (Pimafucin 2.5% eyedrops. Gist-Brocades) was successful.