Thromboembolic Stroke In Patients Research Articles

Nomogram for Risk of Secondary Venous Thromboembolism in Stroke Patients: A Study Based on the MIMIC-IV Database.

This study aims to identify risk factors for secondary venous thromboembolism (VTE) in stroke patients and establish a nomogram, an accurate predictor of probability of VTE occurrence during hospitalization in stroke patients. Medical Information Mart for Intensive Care IV (MIMIC-IV) database of critical care medicine was utilized to retrieve information of stroke patients admitted to the hospital between 2008 and 2019. Patients were randomly allocated into train set and test set at 7:3. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for secondary VTE in stroke patients. A predictive nomogram model was constructed, and the predictive ability of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). This study included 266 stroke patients, with 26 patients suffering secondary VTE after stroke. A nomogram for predicting risk of secondary VTE in stroke patients was built according to pulmonary infection, partial thromboplastin time (PTT), log-formed D-dimer, and mean corpuscular hemoglobin (MCH). Area under the curve (AUC) of the predictive model nomogram was 0.880 and 0.878 in the train and test sets, respectively. The calibration curve was near the diagonal, and DCA curve presented positive net benefit. This indicates the model's good predictive performance and clinical utility. The nomogram effectively predicts the risk probability of secondary VTE in stroke patients, aiding clinicians in early identification and personalized treatment of stroke patients at risk of developing secondary VTE.

Mechanical prophylaxis to prevent venous thromboembolism on stroke patient: a Literature Review

Prevention of Venous Thromboembolism (VTE) is important in the treatment of stroke, including pharmacological and mechanical thromboprophylaxis. One of the post-stroke complications is Deep vein thrombosis (DVT), DVT can lead to pulmonary embolism (PE), and Venous thromboembolism (VTE) is manifested as DVT and PE. Stroke patients are at increased risk of developing DVT. This review aims to assess the clinical efficacy of mechanical prophylaxis for preventing venous thromboembolism in stroke patients. The articles were searched through PubMed, ScienceDirect, Sage Journals and ProQuest database. Keywords: "Stroke", "Prevention", "Deep Vein Thrombosis", “Venous Thromboembolism”, “Intermittent Pneumatic Compression”, and “Stocking Compression” combined using the Boolean operators AND or OR. The articles were full text, written in English, published in the last 10 years, and provided information about mechanical prophylaxis for preventing VTE in stroke patients. This review provides important information on VTE prevention in stroke patients. The use of IPC significantly reduces the risk of DVT and the addition of IPC in pharmacological prophylaxis provides moderate benefits in VTE, whereas the use of graduated compression stocking is less clinically significant in the prevention of VTE. The use of IPC is an effective method to reduce the risk of VTE in post-stroke immobilized patients, with fewer skin side effects compared to stocking compression.

The interaction effect of transfusion history and previous stroke history on the risk of venous thromboembolism in stroke patients: a prospective cohort study

BackgroundBlood transfusion and previous stroke history are two independent risk factors of venous thromboembolism (VTE) in stroke patients. Whether the potential interaction of transfusion history and previous stroke history is associated with a greater risk of VTE remains unclear. This study aims to explore whether the combination of transfusion history and previous stroke history increases the risk of VTE among Chinese stroke patients.MethodsA total of 1525 participants from the prospective Stroke Cohort of Henan Province were enrolled in our study. Multivariate logistic regression models were used to explore the associations among transfusion history, previous stroke history and VTE. The interaction was evaluated on both multiplicative and additive scales. The odds ratio (95% CI), relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (S) of interaction terms were used to examine multiplicative and additive interactions. Finally, we divided our population into two subgroups by National Institutes of Health Stroke Scale (NIHSS) score and re-evaluated the interaction effect in both scales.ResultsA total of 281 (18.4%) participants of 1525 complicated with VTE. Transfusion and previous stroke history were associated with an increased risk of VTE in our cohort. In the multiplicative scale, the combination of transfusion and previous stroke history was statistically significant on VTE in both unadjusted and adjusted models (P<0.05). For the additive scale, the RERI shrank to 7.016 (95% CI: 1.489 ~ 18.165), with the AP of 0.650 (95% CI: 0.204 ~ 0.797) and the S of 3.529 (95% CI: 1.415 ~ 8.579) after adjusting for covariates, indicating a supra-additive effect. In subgroups, the interaction effect between transfusion history and previous stroke history was pronouncedly associated with the increased risk of VTE in patients with NIHSS score > 5 points (P<0.05).ConclusionsOur results suggest that there may be a potential synergistic interaction between transfusion history and previous stroke history on the risk of VTE. Besides, the percentage of VTE incidence explained by interaction increased with the severity of stroke. Our findings will provide valuable evidence for thromboprophylaxis in Chinese stroke patients.

Percutaneous left atrial appendage closure using the LAmbre device in patients with atrial fibrillation and left atrial appendage thrombus.

Left atrial appendage closure (LAAC) is considered a valid alternative for the prevention of thromboembolic stroke in patients with persistent left atrial appendage thrombus (LAAT) despite adequate anticoagulation. However, the data on LAAC using the LAmbre device for patients with LAAT is limited. This study was performed to explore efficacy and safety as well as to share the experience of the modified LAAC procedure with the LAmbre device. A total of 7 patients with persistent LAAT despite adequate anticoagulation underwent modified LAAC with the LAmbre device between November 2019 and April 2022. Transesophageal echocardiography was performed 3 months postoperatively to detect device-related thrombosis and peridevice leak. The patients' clinical events were evaluated during the perioperative and follow-up periods. The median age, CHA2DS2-VASc score, and HAS-BLED score of all patients were 71 [53-73], 3 [2-4], and 2 [2-3], respectively. In the procedure, a cerebral protection system was used in two patients. LAAC with the LAmbre device was successfully performed in all patients without perioperative events. During the median follow-up of 383 [325-865] days, postoperative transesophageal echocardiography was performed in six (85.7%) patients. Device-related thrombosis was detected in one (16.7%) patient, and no significant peridevice leak was observed. No thromboembolic event or bleeding event occurred in any patients. LAAC with the LAmbre device is effective and safe when performed by experienced operators in highly selected patients with LAAT after adequate anticoagulation.

Benefit and harm of anticoagulation in the prevention of thromboembolic stroke for non-valvular atrial fibrillation in haemodialysis patients: a Top End of Northern Australia study.

Warfarin for the prevention of non-valvular atrial fibrillation (AF)-related thromboembolic stroke in patients on maintenance haemodialysis is controversial. Despite the exclusion of haemodialysis patients in randomised control trials, the American Heart Association/American College of Cardiology has recommended warfarin in high-risk AF patients. To retrospectively examine the utility of warfarin anticoagulation therapy in our prevalent haemodialysis patients over 10 years of follow up. Eligible patients were retrospectively identified and stratified to two cohorts based on whether warfarin was prescribed. The outcomes of interest were ischaemic stroke, haemorrhagic stroke and death from any cause. Rate ratio and Cox proportional hazard regression model were used to compare the differences in outcome between the two cohorts. The Kaplan-Meier method was used to analyse survival. Three ischaemic strokes and four haemorrhagic strokes occurred in the unexposed group of 166 patients over 484.44 patient-years of follow up. One ischaemic stroke and no cases of haemorrhagic stroke occurred in the exposed warfarin group of 16 patients over 39.32 patient-years of follow up. Eighty-seven percent of patients in both groups were indigenous. More than 90% of each cohort had a CHA2DS2-VaSc score ≥2. One hundred and one deaths, 90 in the unexposed group and 11 in the warfarin group, occurred in the follow-up period. A non-statistically significant trend towards increasing mortality was observed in the warfarin group (hazard ratio=1.63; P = 0.13). This retrospective study of prevalent haemodialysis patients with co-existing history of non-valvular AF failed to demonstrate sufficient evidence for the routine use of warfarin for prophylaxis of thromboembolic stroke.

Better prediction of stroke in atrial fibrillation with incorporation of cancer in CHA2DS2VASC score: CCHA2DS2VASC score.

IntroductionAtrial fibrillation (AF) is associated with an increased risk of stroke. Despite evidence linking cancer and thrombosis, cancer is not part of the CHA2DS2VASc score.HypothesisCancer is an independent risk factor for thromboembolic stroke in patients with AF.MethodThe SEER database was utilized to identify patients with lung, colon, breast, and prostate cancers with AF and no prior diagnosis of stroke and. compared to controls within the dataset. The primary endpoint was rates of stroke per 100 person-years. Cox regression modeling and a nested model comparing CHA2DS2VASc score (Model 1) with a complete model including cancer diagnosis (Model 2) were performed. Models were compared using Akaike Information Criterion (AIC) and Net Reclassification Index (NRI). A propensity-matched cohort with equivalent CHA2DS2VASc scores determining stroke-free survival was also performed.ResultsA total of 101,185 patients were included in the analysis, with 48,242 in the Cancer and 52,943 in the Non-cancer Group. Stroke rate per 100 person-years was significantly higher in the Cancer Group. The CHA2DS2VASc model (Model 1) was compared against a model including cancer (Model 2) showing improved predictability as assessed by both NRI and AIC. Cox regression analysis calculated a hazard ratio of 1.085 for Cancer, which was comparable to age >75, female sex, and diabetes. Propensity matched Kaplan-Meier curve demonstrated a decreased probability of stroke-free survival in the Cancer Group.ConclusionCancers increase the risk of stroke in patients with AF. Consideration should be given to the addition of cancer to the clinical scoring system.

Abstract 10259: Better Prediction of Stroke in Atrial Fibrillation with Incorporation of Malignancy in Cha2ds2vasc Score: Mcha2ds2vasc Score

Introduction: Atrial fibrillation (AF) is associated with an increased risk of stroke. Despite a large body of evidence linking malignancy and thrombosis, malignancy is not part of the scoring system. Hypothesis: Malignancy is an independent risk factor for the development of thromboembolic stroke in patients with AF. Methods: SEER database was utilized to identify patients with lung, colon, breast, and prostate cancers with AF and no prior diagnosis of stroke. These patients were compared to controls within the dataset. The primary endpoint was ischemic stroke. Rates of stroke per 100 person-years were calculated for each group. Cox regression modeling and a nested model comparing CHA 2 DS s VASc score (Model 1) with a complete model including cancer diagnosis (Model 2) were performed. Models were compared using Akaike Information Criterion (AKI) and Net Reclassification Index (NRI). A propensity matched cohort with equivalent CHA 2 DS 2 VASc scores determining stroke-free survival was also performed. Results: A total of 101,185 patients were included in the analysis, with 48,242 in the Cancer Group and 52,943 in the Non-cancer Group. Stroke rate per 100 person-years was significantly higher in the Cancer Group (2.962) compared with the Non-cancer Group (2.377) (IRR 1·25, 95% CI [1·18-1·31]). The CHA 2 DS 2 VASc model (Model 1) was compared against a model including cancer (Model 2) showing an improved predictability as assessed by both NRI (12·2, 95% CI [10·7-13·7, p&lt;0.01) and AKI. Cox regression analysis calculated a hazard ratio of 1.085 for Cancer (95% CI [1·029-1·44], p = 0·0027), which was comparable to age &gt; 75, female sex, and diabetes. Propensity matched Kaplan-Meier curve demonstrated decreased probability of stroke-free survival in the Cancer Group (p=0·00045). Conclusion: Cancers increase the risk of stroke in patients with AF. Consideration should be given for the addition of malignancy to the clinical scoring systems.

Epicardial obesity and atrial fibrillation: emphasis on atrial fat depot

The studies, performed with MRI and CT, showed that the increase of fat, immediately adjacent to the myocardium (epicardial fat) is correlated more strongly with the risk of atrial fibrillation than the general or abdominal obesity. According to some studies, epicardial fat around the left atrium is a strong predictor of the development at atrial fibrillation. Also, the amount of the fat is associated with the effectiveness of cardioversion and the risk of developing thromboembolic stroke in patients with atrial fibrillation. The number of such works is small, since tomographic examinations are not needed if intra-atrial thrombosis is suspected, and transthoracic echocardiograthy does not allow visualization of atrial fat. However, transesophageal echocardiography is widely used in patients with atrial fibrillation and allows to measure the structures that serve as depots of epicardial fat, namely the interatrial septum and left lateral ridge. Accumulation of epicardial fat leads to thickening of these structures. This can be used to study the relationship between epicardial obesity and the risk of thromboembolic complications in patients with atrial fibrillations.

Эпикардиальное ожирение и фибрилляция предсердий: акцент на предсердном жировом депо

The studies, performed with MRI and CT, showed that the increase of fat, immediately adjacent to the myocardium (epicardial fat) is correlated more strongly with the risk of atrial fibrillation than the general or abdominal obesity. According to some studies, epicardial fat around the left atrium is a strong predictor of the development at atrial fibrillation. Also, the amount of the fat is associated with the effectiveness of cardioversion and the risk of developing thromboembolic stroke in patients with atrial fibrillation. The number of such works is small, since tomographic examinations are not needed if intra-atrial thrombosis is suspected, and transthoracic echocardiograthy does not allow visualization of atrial fat. However, transesophageal echocardiography is widely used in patients with atrial fibrillation and allows to measure the structures that serve as depots of epicardial fat, namely the interatrial septum and left lateral ridge. Accumulation of epicardial fat leads to thickening of these structures. This can be used to study the relationship between epicardial obesity and the risk of thromboembolic complications in patients with atrial fibrillations.

Surgical strategy for atrial fibrillation to prevent stroke in patients undergoing cardiac surgery.

The aim of this study was to compare outcomes of the full maze procedure with left atrial appendage closure (LAAc) as concomitant procedures for atrial fibrillation (AF) in patients undergoing cardiovascular surgery. A total of 151 patients (88 men, 62 women) underwent elective AF surgery concomitantly with cardiovascular surgery from April 2005 to December 2019. The mean age at time of operation was 70years and the mean follow-up period was 5.2 ± 3.8years. Patients were divided into two groups according to the procedure performed: the maze group (n = 87) and the LAAc group (n = 63). Patients in the LAAc group were significantly older and had more comorbidities than those in the maze group. The operative mortality rate was significantly higher in the LAAc group. There was no difference in the rate of freedom from cardiac-related death between the groups (p = 0.86). Furthermore, there was no difference in the 5-year rate of freedom from thromboembolic stroke between the maze group and the LAAc group (p = 0.17). However, the 5-year rate of freedom from heart failure was significantly higher in the maze group compared with the LAAc group (100% vs. 86% ± 6%, respectively; p = 0.006). Patients undergoing the maze procedure had good operative and long-term results, suggesting that this procedure should be performed if indicated. Concomitant LAAc may be effective for preventing thromboembolic stroke in patients with AF if they have no indication for the maze procedure.

Effectiveness and safety of non-pharmacological interventions for the prevention of venous thromboembolism in stroke patients: an overview of systematic reviews

Half of the deaths recorded in non-surgical patients attributable to venous thromboembolism (VTE) affect those with stroke. The uncertain benefit of anticoagulant therapy has increased interest in non-pharmacological intervention to prevent VTE. To evaluate the efficacy and safety of non-pharmacological interventions to prevent VTE in stroke patients. Overview of systematic reviews with retrieval of documents in compliance with the PICOS Framework and through a research strategy implemented on 4 April 2019 in six biomedical databases and in the PROSPERO registry. The tools used to assess the methodological quality and the risk of bias were the AMSTAR checklist and the ROBIS tool, respectively. The results have been synthesized with narrative modality. Seven systematic reviews of different methodological quality and risk of bias met the inclusion criteria. The non-pharmacological interventions of prophylaxis used are graduated compression stockings (GCS) and intermittent pneumatic compression devices (IPCD). The first has no effect on VTE and has important side effects, the second is promising in reducing mortality from all causes and decreases the incidence of deep vein thrombosis. The use of IPCD, despite the efficacy observed, should be reserved, after a risk assessment of VTE and a subgroup analysis, for patients who can derive the maximum benefit from the intervention. In stroke patients the use of GCS to prevent VTE is not recommended because it is not superior to standard care and can cause damage. IPCD as a intervention of prophylaxis appears to be effective but further confirmation is needed from future studies.

Comparative Effectiveness of Direct Oral Anticoagulants and Warfarin for the Treatment of Left Ventricular Thrombus

Introduction Left ventricular (LV) thrombus is a complication of acute endomyocardial injury and chronic ventricular wall hypokinesis (e.g. dilated cardiomyopathy), resulting in increased risk of thromboembolic complications. Historically, observational studies support the general safety and efficacy of warfarin for this indication. To date, limited data exists regarding the use of the direct oral anticoagulants (DOACs) for LV thrombus. Methods A retrospective cohort study utilizing electronic medical records was conducted from September 2012 - October 2018 at the University of Colorado Hospital System. Patients were included if they had any diagnosis of LV thrombus and received either a DOAC or warfarin within 90 days of diagnosis. The primary outcome was to determine the incidence of thromboembolic stroke in patients receiving a DOAC compared to warfarin. Secondary outcomes consisted of the composite incidence of thromboembolic events (stroke and systemic embolism), bleeding rates defined by the The Global Use of Strategies to Open Occluded Arteries (GUSTO) criteria, and blood product administration. Chi square test was used to analyze categorical variables and the student's t-test and Wilcoxon Rank Sum test for continuous data. All statistical analyses were conducted using SAS. Results A total of 949 patients met inclusion, of whom 180 (19%) received a DOAC and 769 (81%) warfarin. Of the DOAC cohort, 77 (41.6%) received rivaroxaban, 79 (42.7%) apixaban, and 29 (15.7%) dabigatran. For baseline demographic information, see table 1. For the primary endpoint of new onset thromboembolic stroke on or within 90 days of LV thrombus diagnosis, no difference existed between treatment groups (DOAC: 7.8% vs warfarin: 11.7%, p=0.524). When compared to warfarin, no difference existed in the composite of thromboembolic events (33.1% vs 30.6%, P=0.524, respectively) or in GUSTO bleeding (11.1% vs 7.8%, p=0.397, for DOAC vs. warfarin, respectively). However, more patients on warfarin received blood products compared to those taking a DOAC (25.8% vs 13.9%, p Conclusions Compared to warfarin, DOACs may be safe and efficacious for the treatment of LV thrombus, however further studies are warranted.

Genome-Wide Copy Number Variation Association Study of Atrial Fibrillation Related Thromboembolic Stroke.

Atrial fibrillation (AF) is a common cardiac arrhythmia and is one of the major causes of ischemic stroke. In addition to the clinical factors such as CHADS2 or CHADS2-VASC score, the impact of genetic factors on the risk of thromboembolic stroke in patients with AF has been largely unknown. Single-nucleotide polymorphisms in several genomic regions have been found to be associated with AF. However, these loci do not contribute to all the genetic risks of AF or AF related thromboembolic risks, suggesting that there are other genetic factors or variants not yet discovered. In the human genome, copy number variations (CNVs) could also contribute to disease susceptibility. In the present study, we sought to identify CNVs determining the AF-related thromboembolic risk. Using a genome-wide approach in 109 patients with AF and thromboembolic stroke and 14,666 controls from the Taiwanese general population (Taiwan Biobank), we first identified deletions in chromosomal regions 1p36.32-1p36.33, 5p15.33, 8q24.3 and 19p13.3 and amplifications in 14q11.2 that were significantly associated with AF-related stroke in the Taiwanese population. In these regions, 148 genes were involved, including several microRNAs and long non-recoding RNAs. Using a pathway analysis, we found deletions in GNB1, PRKCZ, and GNG7 genes related to the alpha-adrenergic receptor signaling pathway that play a major role in determining the risk of an AF-related stroke. In conclusion, CNVs may be genetic predictors of a risk of a thromboembolic stroke for patients with AF, possibly pointing to an impaired alpha-adrenergic signaling pathway in the mechanism of AF-related thromboembolism.

P1206Some potential risk factors for thromboembolic stroke in patients with rheumatoid arthritis and paroxysmal atrial fibrillation

P1206Some potential risk factors for thromboembolic stroke in patients with rheumatoid arthritis and paroxysmal atrial fibrillation

Clinical significance of venous thromboembolism in stroke patients: our experience

要約：静脈血栓塞栓症（venous thromboembolism: VTE）とは肺血栓塞栓症（pulmonary embolism: PE）と深部静脈血栓症（deep vein thrombosis: DVT）の総称であり，近年発症率が増加している．脳卒中領域におけるVTE に対する治療・予防に関してはエビデンスも限られており，本邦でも十分に浸透していないのが現状である．また，各国の脳卒中ガイドラインに目を通すと，早期ROM介入によるDVT 予防はEuropean Stroke Organization guidelines やPolish guidelines of stroke treatment and prevention では推奨されているものの，日本脳卒中ガイドライン2015 やAmerican guidelines，AVERT trial（A Very Early Rehabilitation Trial for Stroke）では言及されておらず，早期リハビリテーション施行によるROM 訓練の重要性について早急に本邦でも評価する必要があると考える．今回，当科における治療経験を踏まえて，脳卒中領域におけるVTE の予防・治療と課題に関して述べる．

Electrical stimulation devices for the prevention of venous thromboembolism: Preliminary studies of physiological efficacy and user satisfaction

IntroductionElectrical stimulation could provide an alternative method for preventing venous thromboembolism in stroke patients. The purpose of this preliminary study was to explore the effects of electrical stimulation and intermittent pneumatic compression on enhancing lower limb venous return in healthy and chronic stroke patients and also to evaluate patient and nurse satisfaction.MethodsWe investigated the effectiveness of two electrical stimulation devices: Geko (Firstkind Ltd, High Wycombe, UK) and Orthopaedic Microstim 2V2 (Odstock Medical Ltd, Salisbury, UK); and one intermittent pneumatic compression device: Huntleigh Flowstron Universal (Huntleigh Healthcare Ltd, Cardiff, UK). We recruited 12 healthy and 5 chronic stroke participants. The devices were fitted sequentially, and Doppler ultrasound measurements were taken. Eight patients and nurses were also recruited for a separate usability evaluation.ResultsThe electrical stimulation devices emulated the blood flow characteristics of intermittent pneumatic compression in both healthy and stroke participants provided that the intensity of electrical stimulation was sufficient. Patients and nurses also felt that the electrical stimulation devices were acceptable.ConclusionsElectrical stimulation may offer benefit as an alternative method for venous thromboembolism prevention in stroke patients. The apparent benefit is sufficient to warrant further investigation in a full powered randomised controlled trial.

C‐reactive protein gene polymorphism predicts the risk of thromboembolic stroke in patients with atrial fibrillation: a more than 10‐year prospective follow‐up study

Background Little evidence is available regarding the impact of genetic polymorphisms on the risk of thromboembolic stroke in patients with atrial fibrillation (AF). An increasing body of evidence is demonstrating that inflammatory responses play an important role in the pathophysiology of AF. Objectives To investigate the effect of genetic polymorphisms of the C-reactive protein (CRP) gene on the incidence of thromboembolic stroke in patients with AF. Methods A total of 725 AF patients were longitudinally followed up for >10years; this is the largest and longest AF follow-up cohort with genetic data. CRP promoter triallelic polymorphisms (C-390A and C-390T) were genotyped, and CRP levels were divided into four quartiles. Results Patients with higher CRP levels were more likely to develop thromboembolic stroke than those with lower CRP levels (P<0.001, log-rank test for comparison of four quartiles). After adjustment for conventional risk factors, patients with higher CRP levels were more likely to develop thromboembolic stroke than those in the lowest CRP quartile (hazard ratio [HR]2.27, 95% confidence interval [CI]1.08-4.81; the lowest CRP quartile was the reference group). Patients carrying the A-390 or T-390 allele had higher CRP levels (3.35±2.71mgL-1 versus 2.43±2.00mgL-1 ), and were more likely to develop thromboembolic stroke, even after adjustment for conventional risk factors (HR2.07, 95% CI1.23-3.48). Conclusion The CRP triallelic polymorphism and the CRP level are associated with the risk of incident thromboembolic stroke in patients with AF.

221 - CHA2DS2VASc Score as a Predictor for Thromboembolic Stroke in Patients with Cardiac Aneurysm

221 - CHA2DS2VASc Score as a Predictor for Thromboembolic Stroke in Patients with Cardiac Aneurysm

Hemopericardium with Tamponade Following Rivaroxaban Administration and Its Attenuation by Cyp3A4 Inhibitors

Novel oral anticoagulants including the factor Xa inhibitor rivaroxaban are important alternatives to warfarin for the prevention of thromboembolic stroke in patients with nonvalvular atrial fibrillation. The pharmacology and metabolism of these agents differ from those of the vitamin K antagonists used over the decades preceding their introduction. We present a case of spontaneous hemopericardium and cardiac tamponade following administration of rivaroxaban. A review of the patient's medications revealed a total of seven agents known to be metabolized through cytochrome P450 3A4 (CYP3A4), the major pathway for rivaroxaban metabolism. While most physicians are familiar with recommendations to monitor renal function in patients prescribed rivaroxaban, we suspect that many fail to evaluate possible interactions with other agents having CYP3A4 inhibitory or inducer activity.

Anticoagulation Therapy Considerations in Factor VII Deficiency.

Factor VII (FVII) deficiency is the most prevalent rare bleeding disorder in the USA and affects approximately 1 out of every 500,000 people. Warfarin inhibits the synthesis of FVII, in addition to other clotting factors. Warfarin is contraindicated in patients with bleeding tendencies or blood dyscrasias; therefore, the literature regarding the use of warfarin in FVII deficiency is very limited. We report a successful re-challenge of warfarin therapy in a patient with FVII deficiency. A 70-year-old woman with FVII deficiency experienced a significant decrease in FVII activity and subsequent vaginal bleeding roughly 5 weeks after starting warfarin for atrial fibrillation. The patient was switched to aspirin therapy. Nearly 4 years later, warfarin therapy was re-attempted by a different haematologist. After 9 months, FVII activity remained in an acceptable range and no bleeding events had occurred. In addition, once the maintenance dose was established, the international normalized ratio remained within the goal range (1.5–2.0) for the majority of assessments. Regarding future considerations, we hypothesize that anticoagulants that do not directly affect FVII, such as the direct oral anticoagulants, would carry less risk of bleeding complications and therefore may be safer alternatives to warfarin to reduce the risk of thromboembolic stroke in patients with atrial fibrillation and FVII deficiency.