ResearchPad - anticoagulant-therapy https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Risk of recurrent venous thromboembolism in patients with HIV infection: A nationwide cohort study]]> https://www.researchpad.co/article/elastic_article_14541 The HIV pandemic affects approximately 40 million people and causes significant morbidity, including a markedly increased risk of a venous thromboembolism (VTE).The recurrence risk of VTE in people living with HIV (PWH) is unknown, although this risk drives the anticoagulant therapy duration after a first VTE.Our study determined the recurrent VTE risk in PWH compared to uninfected controls.What did the researchers do and find?We performed an observational cohort study using data from the national ATHENA PWH cohort (2003–2015) in the Netherlands and the Dutch Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA) cohort (1999–2009) of HIV-uninfected controls with a first VTE.The recurrent VTE incidence rate per 100 person-years of follow-up (PYFU) was higher in PWH (5.2) compared to controls (3.1) yielding a 1.70 hazard ratio (HR; 95% CI 1.23–2.36). Incidence rates were consistently higher for PWH in subgroups stratified by sex or the cause of the first VTE.PWH with lower cluster of differentiation 4 (CD4)+ T-cell counts at their first VTE had fewer recurrent events, which was driven by PWH experiencing a better CD4+ T-cell recovery on HIV treatment prior to anticoagulant discontinuation.What do these findings mean?The risk of recurrent VTE is apparently increased in PWH but is ameliorated with better immune reconstitution.HIV-associated immunodeficiency reflects a reversible risk factor for VTE specific to PWH and is of relevance for decisions on anticoagulant therapy duration. ]]> <![CDATA[Prevalence of drug–drug interaction in atrial fibrillation patients based on a large claims data]]> https://www.researchpad.co/article/N8861b373-c994-4a77-acd1-a0d16f2f19bb

This study aimed to compare and determine the prevalence of drug–drug interaction (DDI) and bleeding rate in atrial fibrillation (AF) patients receiving anticoagulants in a clinical setting. We used large claims data of AF patients obtained from the Japan Medical Data Center. The prevalence of DDIs and cases leading to bleeding events were surveyed clinically relevant DDIs extracted from 1) reported from a spontaneous adverse event reporting system (Japanese Adverse Drug Events Report system; JADER) ≥4 patients; 2) DDIs cited in the package inserts of each anticoagulant (each combination assessed according to “Drug interaction 2015” list; 3) warfarin and quinolone antibiotics DDIs. DDIs were categorized the mechanisms for pharmacokinetic DDI (Cytochrome P450 (CYP) or transporter etc. that modulate blood concentration of anticoagulants)/pharmacodynamic DDI (combination with similar pharmacological actions) or both in the analysis for each patients’ prescriptions obtained from a claims data. AF patients were compared between cases with and without bleeding after administered of anticoagulants. Bleeding was observed in 220/3290 (6.7%) AF patients. The bleeding rate in patients with both pharmacokinetic and pharmacodynamic DDI mechanisms (26.3%) was higher than that in patients with either mechanism (8.6% and 9.2%, respectively) or without DDIs (4.9%). The odds ratio for bleeding in AF patients with both of pharmacokinetic and pharmacodynamic was (7.18 [4.69–11.00], p<0.001). Our study concluded multi mechanism based DDIs leads serious outcome as compared to that of single mechanism based DDIs in AF patients. We determined the prevalence and frequency of bleeding for anticoagulant-related DDIs. To manage DDIs, both pharmacokinetic and pharmacodynamic DDI mechanisms should be closely monitored for initial symptoms of bleeding within the first 3 months.

]]>
<![CDATA[Temporal trends in prevalence and antithrombotic treatment among Asians with atrial fibrillation undergoing percutaneous coronary intervention: A nationwide Korean population-based study]]> https://www.researchpad.co/article/5c478c3ad5eed0c484bd0ebc

Background

We investigated the recent 10-year trends in the number of patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) in relation to prescription patterns of antithrombotic therapy.

Methods

We analyzed the annual prevalence of PCI and patterns of antithrombotic therapy after PCI, including antiplatelets and oral anticoagulants (vitamin K antagonists and non-vitamin K antagonist oral anticoagulants [NOACs]), in patients with AF between 2006 and 2015 by using the Korean National Health Insurance Service database. Independent factors associated with triple therapy (oral anticoagulant plus dual antiplatelet) prescription were assessed using multivariable logistic regression analysis.

Results

The number of patients with AF undergoing PCI increased gradually from 2006 (n = 2,140) to 2015 (n = 3,631) (ptrend<0.001). In 2006, only 22.7% of patients received triple therapy after PCI although 96.2% of them were indicated for anticoagulation (CHA2DS2-VASc score ≥2). The prescription rate of triple therapy increased to 38.3% in 2015 (ptrend<0.001), which was mainly attributed to a recent increment of NOAC-based triple therapy from 2013 (17.5% in 2015). Previous ischemic stroke or systemic embolism, old age, hypertension, and congestive heart failure were significantly associated with a higher triple therapy prescription rate, whereas previous myocardial infarction, PCI, and peripheral arterial disease were associated with triple therapy underuse.

Conclusions

From 2006 to 2015, the number of patients with AF undergoing PCI and the prescription rate of triple therapy increased gradually with a recent increment of NOAC-based antithrombotic therapy from 2013. Previous myocardial infarction, peripheral artery disease, and PCI were associated with underuse of triple therapy.

]]>
<![CDATA[The incidence of left atrial appendage thrombi on transesophageal echocardiography after pretreatment with apixaban for cardioversion in the real-world practice]]> https://www.researchpad.co/article/5c141efdd5eed0c484d2925b

The risk of thromboembolisms during the post-cardioversion period is high. For patients with persistent atrial fibrillation (AF), anticoagulation with warfarin (INR 2.0~3.0) is recommended for at least three weeks prior and four weeks after cardioversion. We aimed to evaluate the efficacy of apixaban in preventing thromboembolic events during post-cardioversion. We enrolled 127 consecutive persistent AF patients (83 persistent, 44 longstanding persistent AF), scheduled to undergo cardioversion and were pretreated with apixaban. All patients underwent transesophageal echocardiography (TEE) to rule out thrombi in the left atrium (LA) or LA appendage (LAA) after anticoagulation with apixaban. The median duration of anticoagulation before the TEE was 37 (interquartile range [IQR] 34, 50) days. There were 7 patients (5.5%) with visible thrombi in the LAA. A spontaneous echo contrast was noted in 24 (18.9%) patients. Cardioversion was attempted in 117 patients, and they were prescribed amiodarone before the elective DC cardioversion. Sinus rhythm was achieved in 37 patients (31.6%) by amiodarone itself. DC cardioversion was attempted in 80 patients and was successful in 73 (91.3%). None of the cardioverted patients had any thromboembolic events within one month. Transient ischemic attacks were observed in one patient during a median follow up period of 202 days (IQR 143, 294). In conclusion, apixaban could be used as an anticoagulant for patients scheduled for cardioversion. However, the incidence of thrombi was not negligible. TEE or other imaging modalities should be considered before cardioversion or other invasive procedures.

]]>
<![CDATA[Rapid and substantial increases in anticoagulant use and expenditure in Australia following the introduction of new types of oral anticoagulants]]> https://www.researchpad.co/article/5c12cf19d5eed0c484913ef6

Objectives

To quantify changes in anticoagulant use in Australia since the introduction of Non-vitamin K antagonist anticoagulants (NOACs) and to estimate government expenditure.

Design

Interrupted-time-series analysis quantifying anticoagulant dispensing, before and after first Pharmaceutical Benefits Scheme (PBS) NOAC listing in August 2009 for venous thromboembolism prevention; and expanded listing for stroke prevention in non-valvular atrial fibrillation (AF) in August 2013, up to June 2016. Estimated government expenditure on PBS-listed anticoagulants.

Setting and participants

PBS dispensing in 10% random sample of Australians, restricted to continuous concessional beneficiaries dispensed oral anticoagulants from July 2005 to June 2016. Total PBS anticoagulant expenditure was calculated using Medicare Australia statistics.

Main outcome measures

Monthly dispensing and initiation of oral anticoagulants (warfarin, rivaroxaban, dabigatran or apixaban). Annual PBS anticoagulant expenditure.

Results

An estimated 149,180 concessional beneficiaries were dispensed anticoagulants (100% warfarin) during July 2005. This increased to 292,550 during June 2016, of whom 47.0%, 27.1%, 18.7% and 7.2% were dispensed warfarin, rivaroxaban, apixaban and dabigatran, respectively. Of 16,500 initiated on anticoagulants in June 2016, 24.3%, 38.2%, 30.0% and 7.5% were initiated on warfarin, rivaroxaban, apixaban, and dabigatran, respectively. Compared to July 2005-July 2013, from August 2013-June 2016, dispensings for all anticoagulants increased by 2,303 dispensings/month (p<0.001, 95%CI = [1,229 3,376]); warfarin dispensing decreased by 1,803 dispensings/month (p<0.001, 95%CI = [–2,606, –1,000]). Total PBS anticoagulant expenditure was $19.5 million (97.0% concessional) in 2008/09, of which 100% was warfarin and $203.3 million (86.2% concessional) in 2015/16, of which 11.2% was warfarin.

Conclusions

The introduction of the NOACs led to substantial increases in anticoagulant use and expenditure in Australia.

]]>
<![CDATA[Effects of thrombolysis on outcomes of patients with deep venous thrombosis: An updated meta-analysis]]> https://www.researchpad.co/article/5bb3df3440307c54ff8ce8ef

Background

Small randomized controlled studies and meta-analyses have shown that thrombolysis, especially catheter-directed thrombolysis, can reduce the incidence of post-thrombotic syndrome (PTS). However, the recent ATTRACT trial did not demonstrate the same effects. Given this confusing situation, we performed an updated meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of thrombolysis, especially catheter-directed thrombolysis, on the outcomes of deep venous thrombosis (DVT).

Methods

We searched PubMed, Embase, and the Cochrane Library for relevant studies comparing thrombolysis in combination with anticoagulation and with anticoagulation alone. The primary endpoint was PTS during the longest follow-up period. The safety endpoint was the incidence of major bleeding events. We also evaluated the outcomes of catheter-directed thrombolysis as a subgroup analysis.

Results

Six RCTs, including 1418 patients with DVT, were included in our meta-analysis. Thrombolysis in combination with anticoagulation did not reduce PTS (RR: 0.90, [0.80–1.01], P = 0.19) and increased major bleeding (RR: 2.07, [1.12–3.81], P = 0.02). However, trial sequential analysis (TSA) showed that more patients are needed to support the conclusion that thrombolysis in combination with anticoagulation increased major bleeding. Catheter-directed thrombolysis did not reduce the incidence of PTS (RR: 0.88, [0.68–1.13], P = 0.31) and did increase the incidence of major bleeding events (RR: 1.89, [1.00–3.59], P = 0.05).

Conclusion

Thrombolysis, including catheter-directed thrombolysis, did not reduce the incidence of PTS and increased the incidence of major bleeding. However, the results were not supported by TSA and sensitivity analysis, so more relevant studies are needed.

]]>
<![CDATA[Anticoagulation Intensity of Rivaroxaban for Stroke Patients at a Special Low Dosage in Japan]]> https://www.researchpad.co/article/5989daa7ab0ee8fa60ba7d09

Objectives

In Japan, low-dose rivaroxaban [15 mg QD/10 mg QD for creatinine clearance of 30–49 mL/min] was approved for clinical use in NVAF patients partly because of its unique pharmacokinetics in Japanese subjects. The aim of the study was to determine the anticoagulation intensity of rivaroxaban and its determinant factors in Japanese stroke patients.

Methods

Consecutive stroke patients with NVAF admitted between July 2012 and December 2013 were studied. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and estimated plasma concentration of rivaroxaban (Criv) based on an anti-factor Xa chromogenic assay were measured just before and 4 and 9 h after administration at the steady state level of rivaroxaban. Determinant factors for Criv were explored using a linear mixed-model approach.

Results

Of 110 patients (37 women, 75±9 years old), 59 took 15 mg QD of rivaroxaban and 51 took 10 mg QD. Criv at 4 h was 186 ng/mL for patients taking 15 mg QD and 147 ng/mL for those taking 10 mg QD. Both PT and aPTT were positively correlated with Criv. Criv was 72% lower at 4 h in 15 patients receiving crushed tablets than in the other patients, and tablet crushing was significantly associated with lower Criv (adjusted estimate −0.43, 95% CI −0.60 to −0.26) after multivariate-adjustment.

Conclusion

The anticoagulation effects of rivaroxaban in the acute stroke setting for Japanese NVAF patients were relatively low as compared with those in the ROCKET-AF and J-ROCKET AF trials. Tablet crushing, common in dysphagic patients, decreased Criv.

]]>
<![CDATA[Long Term Outcome after Application of the Angio-Seal Vascular Closure Device in Minipigs]]> https://www.researchpad.co/article/5989da50ab0ee8fa60b8da68

Minipigs are frequently used in (neuro-)interventional research. Longitudinal experiments may require repeated vessel access via the femoral artery. Anticoagulation and incompliance of the animals necessitates the use of a vascular closure device (VCD). The effects of the Angio-Seal VCD in minipigs were longitudinally assessed. Minipig (42±8.4 kg body weight) femoral arteries were sealed using the 8F (n = 6) or 6F (n = 7) Angio-Seal VCD. The pre-interventional femoral artery diameter was 5.1±0.4 mm (4.3–5.8 mm). Sealed puncture sites were analysed angiographically as well as by computed tomography angiography (CTA) for a mean period of 14.1±8.0 weeks (1–22 weeks). All animals were constantly treated with acetylsalicylic acid (ASS) (450 mg/d (n = 7) or 100 mg/d (n = 1)) and clopidogrel (75 mg/d (n = 8)). Non-instrumented (n = 2) and arteries sealed using the VCD (n = 2) were examined histologically. No postoperative hemorrhagic complications were observed. Three arteries were occluded after VCD placement (1 animal diagnosed after 4 weeks (8F), 2 animals after 1 week (6F)) and remained so until the end of the experiments after 22, 12 and 4 weeks, respectively. In one artery a 50% stenosis 8 weeks after application of a 6F Angio-Seal was detected. In 69.2% (n = 9) the VCD was applied without complications. Histopathological analysis of the sealed arterial segments showed subtotal obliteration of the vessel lumen, formation of collagenous tissue and partial damage of the internal elastic lamina. The Angio-Seal VCD prevents relevant hemorrhagic complications in minipigs treated with dual platelet inhibition, but is associated with increased vessel occlusion rates.

]]>
<![CDATA[Analysis of Thrombophilia Test Ordering Practices at an Academic Center: A Proposal for Appropriate Testing to Reduce Harm and Cost]]> https://www.researchpad.co/article/5989da73ab0ee8fa60b9587b

Ideally, thrombophilia testing should be tailored to the type of thrombotic event without the influence of anticoagulation therapy or acute phase effects which can give false positive results that may result in long term anticoagulation. However, thrombophilia testing is often performed routinely in unselected patients. We analyzed all consecutive thrombophilia testing orders during the months of October and November 2009 at an academic teaching institution. Information was extracted from electronic medical records for the following: indication, timing, comprehensiveness of tests, anticoagulation therapy at the time of testing, and confirmatory repeat testing, if any. Based on the findings of this analysis, we established local guidelines in May 2013 for appropriate thrombophilia testing, primarily to prevent testing during the acute thrombotic event or while the patient is on anticoagulation. We then evaluated ordering practices 22 months after guideline implementation. One hundred seventy-three patients were included in the study. Only 34% (58/173) had appropriate indications (unprovoked venous or arterial thrombosis or pregnancy losses). 51% (61/119) with an index clinical event were tested within one week of the event. Although 46% (79/173) were found to have abnormal results, only 46% of these had the abnormal tests repeated for confirmation with 54% potentially carrying a wrong diagnosis with long term anticoagulation. Twenty-two months after guideline implementation, there was an 84% reduction in ordered tests. Thus, this study revealed that a significant proportion of thrombophilia testing was inappropriately performed. We implemented local guidelines for thrombophilia testing for clinicians, resulting in a reduction in healthcare costs and improved patient care.

]]>
<![CDATA[Quality Improvement in Acute Ischemic Stroke Care in Taiwan: The Breakthrough Collaborative in Stroke]]> https://www.researchpad.co/article/5989daabab0ee8fa60ba9612

In the management of acute ischemic stroke, guideline adherence is often suboptimal, particularly for intravenous thrombolysis or anticoagulation for atrial fibrillation. We sought to improve stroke care quality via a collaborative model, the Breakthrough Series (BTS)-Stroke activity, in a nationwide, multi-center activity in Taiwan. A BTS Collaborative, a short-term learning system for a large number of multidisciplinary teams from hospitals, was applied to enhance acute ischemic stroke care quality. Twenty-four hospitals participated in and submitted data for this stroke quality improvement campaign in 2010–2011. Totally, 14 stroke quality measures, adopted from the Get With The Guideline (GWTG)-Stroke program, were used to evaluate the performance and outcome of the ischemic stroke patients. Data for a one-year period from 24 hospitals with 13,181 acute ischemic stroke patients were analyzed. In 14 hospitals, most stroke quality measures improved significantly during the BTS-activity compared with a pre-BTS-Stroke activity period (2006–08). The rate of intravenous thrombolysis increased from 1.2% to 4.6%, door-to-needle time ≤60 minutes improved from 7.1% to 50.8%, symptomatic hemorrhage after intravenous thrombolysis decreased from 11.0% to 5.6%, and anticoagulation therapy for atrial fibrillation increased from 32.1% to 64.1%. The yearly composite measures of five stroke quality measures revealed significant improvements from 2006 to 2011 (75% to 86.3%, p<0.001). The quarterly composite measures also improved significantly during the BTS-Stroke activity. In conclusion, a BTS collaborative model is associated with improved guideline adherence for patients with acute ischemic stroke. GWTG-Stroke recommendations can be successfully applied in countries besides the United States.

]]>
<![CDATA[Use of the SAMe-TT2R2 Score to Predict Good Anticoagulation Control with Warfarin in Chinese Patients with Atrial Fibrillation: Relationship to Ischemic Stroke Incidence]]> https://www.researchpad.co/article/5989da56ab0ee8fa60b8efb9

Background

The efficacy and safety of warfarin therapy for stroke prevention in atrial fibrillation (AF) depends on the time in therapeutic range (TTR). We aimed to assess the predictive ability of SAMe-TT2R2 score in Chinese AF patients on warfarin, whose TTR is notoriously poor.

Methods and Results

This is a single-centre retrospective study. Patients with non-valvular AF on warfarin diagnosed between 1997 and 2011 were stratified according to SAMe-TT2R2 score, and TTR was calculated using Rosendaal method. The predictive power of SAMe-TT2R2 scores for good TTR i.e. >70% was assessed. We included 1,428 Chinese patients (mean age 76.2±8.7 years, 47.5% male) with non-valvular AF on warfarin. The mean and median TTR were 38.2±24.4% and 38.8% (interquartile range: 17.9% and 56.2%) respectively. TTR decreased progressively with increasing SAMe-TT2R2 score (p = 0.016). When the cut-off value of SAMe-TT2R2 score was set to 2, the sensitivity and specificity to predict TTR<70% were 85.7% and 17.8%, respectively. The corresponding positive and negative predictive values were 10.1% and 92.0%. After a mean follow-up of 4.7±3.6 years, 338 patients developed an ischemic stroke (4.96%/year). Patients with TTR≥70% had a lower annual risk of ischemic stroke of 3.67%/year compared with than those with TTR<70% (5.13%/year)(p = 0.08). Patients with SAMe-TT2R2 score ≤2 had the lowest risk of annual risk of ischemic stroke (3.49%/year) compared with those with SAMe-TT2R2 score = 3 (4.56%/year), and those with SAMe-TT2R2 score ≥4 (6.41%/year)(p<0.001). There was also a non-significant trend towards more intracranial hemorrhage with increasing SAMe-TT2R2 score.

Conclusions

The SAMe-TT2R2 score correlates well with TTR in Chinese AF patients, with a score >2 having high sensitivity and negative predictive values for poor TTR. Ischemic stroke risk increased progressively with increasing SAMe-TT2R2 score, consistent with poorer TTRs at high SAMe-TT2R2 scores.

]]>
<![CDATA[Anticoagulation Management Practices and Outcomes in Elderly Patients with Acute Venous Thromboembolism: A Clinical Research Study]]> https://www.researchpad.co/article/5989da1aab0ee8fa60b7c7c9

Whether anticoagulation management practices are associated with improved outcomes in elderly patients with acute venous thromboembolism (VTE) is uncertain. Thus, we aimed to examine whether practices recommended by the American College of Chest Physicians guidelines are associated with outcomes in elderly patients with VTE. We studied 991 patients aged ≥65 years with acute VTE in a Swiss prospective multicenter cohort study and assessed the adherence to four management practices: parenteral anticoagulation ≥5 days, INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulation, early start with vitamin K antagonists (VKA) ≤24 hours of VTE diagnosis, and the use of low-molecular-weight heparin (LMWH) or fondaparinux. The outcomes were all-cause mortality, VTE recurrence, and major bleeding at 6 months, and the length of hospital stay (LOS). We used Cox regression and lognormal survival models, adjusting for patient characteristics. Overall, 9% of patients died, 3% had VTE recurrence, and 7% major bleeding. Early start with VKA was associated with a lower risk of major bleeding (adjusted hazard ratio 0.37, 95% CI 0.20–0.71). Early start with VKA (adjusted time ratio [TR] 0.77, 95% CI 0.69–0.86) and use of LMWH/fondaparinux (adjusted TR 0.87, 95% CI 0.78–0.97) were associated with a shorter LOS. An INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulants was associated with a longer LOS (adjusted TR 1.2, 95% CI 1.08–1.33). In elderly patients with VTE, the adherence to recommended anticoagulation management practices showed mixed results. In conclusion, only early start with VKA and use of parenteral LMWH/fondaparinux were associated with better outcomes.

]]>
<![CDATA[Comparison of the Non-VKA Oral Anticoagulants Apixaban, Dabigatran, and Rivaroxaban in the Extended Treatment and Prevention of Venous Thromboembolism: Systematic Review and Network Meta-Analysis]]> https://www.researchpad.co/article/5989db39ab0ee8fa60bd43c8

Background

Historically, warfarin or aspirin have been the recommended therapeutic options for the extended treatment (>3 months) of VTE. Data from Phase III randomised controlled trials (RCTs) are now available for non-VKA oral anticoagulants (NOACs) in this indication. The current systematic review and network meta-analysis (NMA) were conducted to compare the efficacy and safety of anticoagulants for the extended treatment of VTE.

Methods

Electronic databases (accessed July 2014 and updated April 2016) were systematically searched to identify RCTs evaluating apixaban, aspirin, dabigatran, edoxaban, rivaroxaban, and warfarin for the extended treatment of VTE. Eligible studies included adults with an objectively confirmed deep vein thrombosis, pulmonary embolism or both. A fixed-effect Bayesian NMA was conducted, and results were presented as relative risks (RRs). Sensitivity analyses examining (i) the dataset employed according to the time frame for outcome assessment (ii) the model used for the NMA were conducted.

Results

Eleven Phase III RCTs (examining apixaban, aspirin, dabigatran, rivaroxaban, warfarin and placebo) were included. The risk of the composite efficacy outcome (VTE and VTE-related death) was statistically significantly lower with the NOACs and warfarin INR 2.0–3.0 compared with aspirin, with no significant differences between the NOACs. Treatment with apixaban (RR 0.23, 95% CrI 0.10, 0.55) or dabigatran (RR 0.55, 95% Crl 0.43, 0.71) was associated with a statistically significantly reduced risk of ‘major or clinically relevant non-major bleed’ compared with warfarin INR 2.0–3.0. Apixaban also showed a significantly reduced risk compared with dabigatran (RR 0.42, 95% Crl 0.18, 0.97) and rivaroxaban (RR 0.23, 95% Crl 0.09, 0.59). Sensitivity analyses indicate that results were dependent on the dataset, but not on the type of NMA model employed.

Conclusions

Results from the NMA indicate that NOACs are an effective treatment for prevention of VTE or VTE-related death) in the extended treatment setting. However, bleeding risk differs between potential treatments, with apixaban reporting the most favourable profile compared with other NOACs, warfarin INR 2.0–3.0, and aspirin.

]]>
<![CDATA[The Active Metabolite of Warfarin (3'-Hydroxywarfarin) and Correlation with INR, Warfarin and Drug Weekly Dosage in Patients under Oral Anticoagulant Therapy: A Pharmacogenetics Study]]> https://www.researchpad.co/article/5989da05ab0ee8fa60b7564d

Objectives

Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3’-hydroxywarfarin, and drug weekly dosage aimed at searching novel alternatives to OAT monitoring. VKORC1/CYP2C9 pharmacogenetics investigation was performed to account for the known influence on warfarin homeostasis.

Methods

133 OAT patients were recruited and assessed for warfarin/3’-hydroxywarfarin serum levels (HPLC), INR, and VKORC1 and CYP2C9 genotypes. A subgroup of 52 patients were monitored in detail (5 consecutive controls; c0-c4) till the target INR was reached. Correlation analyses were performed in both groups

Results

In the whole OAT group both warfarin and 3’-hydroxywarfarin correlate with INR at comparable degree (r2 = 0.0388 and 0.0362 respectively). Conversely, warfarin weekly dosage better correlates with warfarin than with 3’-hydroxywarfarin (r2 = 0.0975 and r2 = 0.0381 respectively), but considering together warfarin plus 3’-hydroxywarfarin the correlation strongly increased (r2 = 0.1114; p<0.0001). Interestingly, 3’-hydroxywarfarin reached a strong correlation at c4 respect to warfarin (r2 = 0.2157 and r2 = 0.0549; p = 0.0005 and p = 0.0944 respectively) seeming less affected by drug adjustments in the subgroup of 52 patients who started OAT. The multivariate analyses aimed at estimating the true contribution of 3’-hydroxywarfarin on INR value ascribed it the unique significant value (p = 0.0021) in spite of warfarin who lost association. The pharmacogenetics studies confirmed that patients carrying the VKORC1 variant-allele required lower warfarin maintenance dosage and that the combination of VKORC1 and CYP2C9 yielded a warfarin responsive index (WRI) inversely related to the number variant alleles

Conclusion

Our results overall suggest that 3’-hydroxywarfarin monitoring could be of great advantage in INR monitoring respect to classical warfarin assessment showing significant contribution also in multivariate analysis. Therefore, additional active metabolites should be recognized and investigated as novel useful indicators.

]]>
<![CDATA[The New 3D Printed Left Atrial Appendage Closure with a Novel Holdfast Device: A Pre-Clinical Feasibility Animal Study]]> https://www.researchpad.co/article/5989da0cab0ee8fa60b78074

Introduction

Many patients undergoing cardiac surgery have risk factors for both atrial fibrillation (AF) and stroke. The left atrial appendage (LAA) is the primary site for thrombi formation. The most severe complication of emboli derived from LAA is stroke, which is associated with a 12-month mortality rate of 38% and a 12-month recurrence rate of 17%. The most common form of treatment for atrial fibrillation and stroke prevention is the pharmacological therapy with anticoagulants. Nonetheless this form of therapy is associated with high risk of major bleeding. Therefore LAA occlusion devices should be tested for their ability to reduce future cerebral ischemic events in patients with high-risk of haemorrhage.

Aim

The aim of this study was to evaluate the safety and feasibility of a novel left atrial appendage exclusion device with a minimally invasive introducer in a swine model.

Materials and Methods

A completely novel LAA device, which is composed of two tubes connected together using a specially created bail, was designed using finite element modelling (FEM) to obtain an optimal support force of 36 N at the closure line. The monolithic form of the occluder was obtained by using additive manufacturing of granular PA2200 powder with the technology of selective laser sintering (SLS). Fifteen swine were included in the feasibility tests, with 10 animals undergoing fourteen days of follow-up and 5 animals undergoing long-term observation of 3 months. For one animal, the follow-up was further prolonged to 6 months. The device was placed via minithoracotomy. After the observation period, all of the animals were euthanized, and their hearts were tested for LAA closure and local inflammatory and tissue response.

Results

After the defined observation period, all fifteen hearts were explanted. In all cases the full closure of the LAA was achieved. The macroscopic and microscopic evaluation of the explanted hearts showed that all devices were securely integrated in the surrounding tissues. No pericarditis or macroscopic signs of inflammation at the site of the device were found. All pigs were in good condition with normal weight gain and no other clinical symptoms.

Conclusion

This novel 3D printed left atrial appendage closure technique with a novel holdfast device was proven to be safe and feasible in all pigs. A benign healing process without inflammation and damage to the surrounding structures or evidence of new thrombi formation was observed. Moreover, the uncomplicated survival and full LAA exclusion in all animals demonstrate the efficacy of this novel and relatively cheap device. Further clinical evaluation and implementation studies should be performed to introduce this new technology into clinical practice.

]]>
<![CDATA[Areas of improvement in anticoagulant safety. Data from the CACAO study, a cohort in general practice]]> https://www.researchpad.co/article/5989db51ab0ee8fa60bdc46c

Background

Real-world studies on anticoagulants are mostly performed on health insurance databases, limited to reported events, and sometimes far from every-day issues in family practice. We assess the presence of data for safe monitoring of oral anticoagulants in general practice, and compare patients’ knowledge of taking an anticoagulant between vitamin K antagonists (VKA) and direct anticoagulants (DOAC), and the general practitioner’s perception of their adherence to anticoagulation.

Methods

The CACAO study is a national cohort study, conducted by general practitioners on ambulatory patients under oral anticoagulant. In the first phase, investigators provided safety data available from medical records at inclusion. They also evaluated patients’ knowledge about anticoagulation and graded their perception of patients’ adherence.

Results

Between April and December 2014, 463 general practitioners included 7154 patients. Renal and hepatic function tests were respectively unavailable in 109 (7.5%) and 359 (24.7%) DOAC patients. Among patients with atrial fibrillation, 345 patients (6.9%) had a questionable indication of anticoagulant (CHA2DS2-Vasc<2). One hundred and thirty-three VKA patients (2.3%) and 70 DOAC patients (4.9%) answered they took no anticoagulant (p<0.0001). According to general practitioners’ perception, 430 patients (6.1%) were classified as “not very” or “not adherent”, with no difference between groups.

Conclusions

Our results highlight the efforts needed to improve anticoagulant safety in daily practice: decreasing the rate of unknown biological data in patients with DOACs or the rate of patients with VKA with no strong indication of anticoagulation, and improving patient knowledge with regard to their anticoagulant. Patients’ adherence seems highly over-estimated by the general practitioners.

Clinical trial registration

ClinicalTrials.gov NCT02376777

]]>
<![CDATA[Prevalence of Atrial Fibrillation and Antithrombotic Therapy in Hemodialysis Patients: Cross-Sectional Results of the Vienna InVestigation of AtriaL Fibrillation and Thromboembolism in Patients on HemoDIalysis (VIVALDI)]]> https://www.researchpad.co/article/5989db44ab0ee8fa60bd804f

Background

Atrial fibrillation (AF) adds significant risk of stroke and thromboembolism in patients on hemodialysis (HD). The aim of this study was to investigate the prevalence of AF in a population-based cohort of HD patients and practice patterns of antithrombotic therapy for stroke prevention in AF.

Methods

The Vienna InVestigation of AtriaL fibrillation and thromboembolism in patients on hemodialysis (VIVALDI), an ongoing prospective observational cohort study, investigates the prevalence of AF and the risk of thromboembolic events in HD patients in Vienna, Austria. We analyzed cross-sectional data of 626 patients (63.4% men, median age 66 years, approx. 73% of HD patients in Vienna), who provided informed consent. A structured interview with each patient was performed, recent and archived ECGs were viewed and medical histories were verified with electronic records.

Results

The overall prevalence of AF was 26.5% (166 patients, 71.1% men, median age 72 years) of which 57.8% had paroxysmal AF, 3.0% persistent AF, 32.5% permanent AF, and 6.6% of patients had newly diagnosed AF. The median CHA2DS2-VASc Score was 4 [25th-75th percentile 3–5]. In multivariable analysis, AF was independently associated with age (odds ratio: 1.05 per year increase, 95% confidence interval: 1.03–1.07), male sex (1.7, 1.1–2.6), history of venous thromboembolism (2.0, 1.1–3.6), congestive heart failure (1.7, 1.1–2.5), history of or active cancer (1.5, 1.0–2.4) and time on HD (1.08 per year on HD, 1.03–1.13). Antithrombotic treatment was applied in 84.4% of AF patients (anticoagulant agents in 29.5%, antiplatelet agents in 33.7%, and both in 21.1%). In AF patients, vitamin-K-antagonists were used more often than low-molecular-weight heparins (30.1% and 19.9%).

Conclusions

The prevalence of AF is high amongst HD patients and is associated with age, sex, and distinct comorbidities. Practice patterns of antithrombotic treatment indicate a lack of consensus for stroke prevention in HD patients with AF.

]]>
<![CDATA[Patient-Reported Treatment Satisfaction with Rivaroxaban for Stroke Prevention in Atrial Fibrillation. A French Observational Study, the SAFARI Study]]> https://www.researchpad.co/article/5989d9dfab0ee8fa60b68d7a

Background

For antithrombotic treatments, Patient Reported Outcomes (PRO) and patient satisfaction with treatment are essential data for physicians because of the strong relationship between patient satisfaction and adherence to treatment. The impact of rivaroxaban on patient satisfaction and quality of life was not sufficiently documented in phase III studies. There is a need for further data in this field especially in real life conditions.

Methods

The SAFARI study is composed of patients with non-valvular atrial fibrillation (AF), previously treated with vitamin K antagonist (VKA) and switched to rivaroxaban. Patient satisfaction with anticoagulant therapy was measured by the Anti-Clot Treatment Scale (ACTS), a validated 15-item patient-reported scale including a 12-item ACTS Burdens scale and a 3-item ACTS Benefits scale. Satisfaction of medication was compared between baseline and 1, 3 and 6 months.

Results

Study population was composed of 405 patients. Mean age was 74.8 (standard deviation = 9.0) years and 63.0% were male. Mean CHA2DS2-VASc score was 3.4 (1.5) and mean HAS-BLED score was 2.9 (1.0). After 3 months of treatment with rivaroxaban, patient satisfaction improved compared with VKA: mean ACTS burdens scores significantly increased by 8.3 (8.9) points (p<0.0001) and ACTS benefits scale by 0.4 (2.9) (p<0.001). Compared with baseline, the improvement in ACTS burdens and benefits became apparent at 1 month (46.5 vs. 53.6 p<0.001 and 10.4 vs. 10.7, p<0.05 respectively) and persisted at 6 months (46.5 vs. 54.76 p<0.001 and 10.4 vs. 10.8 p = 0.02 respectively). Rivaroxaban persistence was 88.7% at 6 months.

Conclusions

SAFARI data support a good risk-benefit balance for rivaroxaban, with a good safety profile and encourage PRO design studies. The switch from VKA to rivaroxaban improved patient satisfaction at 1, 3 and 6 months after rivaroxaban initiation among patients with AF, particularly in reducing patient-reported anticoagulation burden.

]]>