Antiplatelet and anticoagulation use and risk of bleeding from percutaneous dilatational tracheostomy insertion: Systematic review and meta-analysis

Introduction

Antiplatelet and anticoagulation therapies are frequently required in acutely unwell patients and confer an increased propensity for procedural bleeding. During percutaneous tracheostomy insertion, the decision to stop these therapies is left to clinical decision-makers. This meta-analysis summarises the risk of bleeding associated with antiplatelet and anticoagulation therapy during percutaneous tracheostomy insertion.

Method

We conducted a systematic review and meta-analysis of studies which reported intraoperative bleeding during percutaneous tracheostomy while on single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT), as well as therapeutic anticoagulation (TAC). Groups were compared against those with prophylactic or no anticoagulation. Studies were pooled using random effects via the inverse variance method.

Results

Four databases found 22 eligible studies, of which 14 studies presented data for meta-analysis representing 3,485 percutaneous tracheostomy insertion procedures. These included six studies that reported intraoperative bleeding outcome SAPT, six for DAPT and five for TAC. Overall, methodological quality was poor. No significant association was found for SAPT (Odds ratio 1.58; 95% confidence interval 0.72-4.41); P = 0.25; I 2 = 81%) and TAC (OR 1.79; 95% CI 0.58-5.56; P = 0.35; I2 = 35%). The DAPT group was associated with increased bleeding with an OR of 2.05 (95% CI 1.18-3.56; P = 0.01; I 2 = 0%).

Conclusion

Our study supports temporarily withholding DAPT or TAC (if clinically feasible) to minimize bleeding risks associated with percutaneous dilatational tracheostomy.

Accuracy and technical characteristics of CYP2C19 point of care tests: a systematic review

Aim: To assess the accuracy and technical characteristics of CYP2C19 point of care tests (POCTs).Patients & methods: Systematic review of primary studies, in any population or setting, that evaluated POCTs for detecting CYP2C19 loss of function (LOF) alleles.Results: Eleven studies provided accuracy data (eight Spartan; one Genomadix Cube; one GMEX; one Genedrive). The POCTs had very high sensitivity and specificity for the alleles they tested for. Twenty-two studies reported technical characteristics: POCTs were easy to operate and provided results quickly. Limited data were reported for test failure rate and cost.Conclusion: CYP2C19 POCTs may be a useful alternative to laboratory-based testing to guide antiplatelet therapy. Further data are required on accuracy (GMEX; Genedrive), test failure and cost (all POCT).

Point-of-Care Testing in Patients with Hereditary Disorders of Primary Hemostasis: A Narrative Review

Inherited disorders of primary hemostasis, such as von Willebrand disease and congenital platelet disorders, can cause extensive, typically mucocutaneous bleeding. Assays to diagnose and monitor these disorders, such as von Willebrand factor activity assays and light transmission aggregometry, are performed in specialized hemostasis laboratories but are commonly not available in local hospitals. Due to the complexity and relative scarcity of these conventional assays, point-of-care tests (POCT) might be an attractive alternative in patients with hereditary bleeding disorders. POCTs, such as thromboelastography, are increasingly used to assess hemostasis in patients with acquired hemostatic defects, aiding clinical decision-making in critical situations, such as during surgery or childbirth. In comparison, the use of these assays in patients with hereditary hemostasis defects remains relatively unexplored. This review aims to give an overview of point-of-care hemostasis tests in patients with hereditary disorders of primary hemostasis. A summary of the literature reporting on the performance of currently available and experimental POCTs in these disorders is given, and the potential utility of the assays in various use scenarios is discussed. Altogether, the studies included in this review reveal that several POCTs are capable of identifying and monitoring severe defects in the primary hemostasis, while a POCT that can reliably detect milder defects of primary hemostasis is currently lacking. A better understanding of the strengths and limitations of POCTs in assessing hereditary defects of primary hemostasis is needed, after which these tests may become available for clinical practice, potentially targeting a large group of patients with milder defects of primary hemostasis.

Interpreting coagulation mixing study results in the era of direct oral anticoagulants

Interpretation of coagulation mixing studies is complicated by interference arising from direct oral anticoagulants (DOACs), which are increasingly prescribed. In this retrospective study, we reviewed 1035 consecutive coagulation mixing studies performed from 2017 to 2021. Three hundred and ninety-nine cases with normal prothrombin time (PT) and activated partial thromboplastin time (aPTT) were excluded. aPTT mixing studies were performed at time 0 and after 60 min of incubation. We confirmed the presence of interfering factors with additional laboratory testing, medication records, and medical history. Mixing corrected most prolonged PT samples (93%), but 32 cases showed incomplete correction. Of these 32 cases, 18 were confounded by DOAC use, and 3 by factor V (FV) inhibitor. We observed an unusual pattern of prolongation of aPTT after incubation, which was previously considered a characteristic of specific factor inhibitors, most commonly FVIII inhibitor. However, we found that lupus anticoagulant (28%) and DOAC (25%) contributed to this pattern similarly as specific factor inhibitors (28%). Coagulation laboratories should be aware of interference arising from DOACs and other factors in PT/aPTT mixing studies, especially in some unusual correction patterns.

Enhancing postoperative anticoagulation therapy with remote patient monitoring: A pilot crossover trial study to evaluate portable coagulometers and chatbots in cardiac surgery follow-up

Objective

Prior research has not assessed the value of remote patient monitoring (RPM) systems for patients undergoing anticoagulation therapy after cardiac surgery. This study aims to assess whether the clinical follow-up through RPM yields comparable outcomes with the standard protocol.

Methods

A crossover trial assigned participants to SOC-RPM or RPM-SOC, starting with the standard of care (SOC) for the first 6 months after surgery and using RPM for the following 6 months, or vice-versa, respectively. During RPM, patients used the Coaguchek© to accurately measure International Normalized Ratio values and a mobile text-based chatbot to report PROs and adjust the therapeutic dosage. The study assessed patients' and clinicians' experience with RPM and compared direct costs.

Results

Twenty-seven patients participated. The median time in therapeutic range (TTR) levels during RPM were 72.2% and 50.6% for the SOC-RPM and RPM-SOC arms, respectively, and during SOC, they were 49.4% and 58.4% for SOC-RPM and RPM-SOC arms, respectively. Patients and the clinical team reported high trust and satisfaction with the proposed digital service. Statistically significant differences were only found in the cost of RPM in the RPM-SOC, which was higher than SOC in the SOC-RPM arm.

Conclusions

Portable coagulometers and chatbots can enhance the remote management of patients undergoing anticoagulation therapy, improving patient experience. This presents a promising alternative to the current standard procedure. The results of this study seem to suggest that RPM may have a higher value when initiated after a SOC period rather than starting RPM immediately after surgery.Trial registration: ClinicalTrials.gov NCT06423521.

The Prevalence of Gastrointestinal Bleeding in COVID-19 Patients: A Systematic Review and Meta-Analysis

Introduction: Severe acute respiratory syndrome coronavirus 2 caused the coronavirus disease of 2019 (COVID-19), which rapidly became a pandemic, claiming millions of lives. Apart from the main manifestations of this infection concerning the respiratory tract, such as pneumonia, there are also many manifestations from the gastrointestinal tract. Of these, bleeding from the gastrointestinal tract is a significant complication quite dangerous for life. This bleeding is divided into upper and lower, and the primary pathophysiological mechanism is the entering of the virus into the host cells through the Angiotensin-converting enzyme 2 receptors. Also, other comorbidities and the medication of corticosteroids and anticoagulants are considered to favor the occurrence of gastrointestinal bleeding (GIB). Methods: This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the studies were searched in two different databases (Scopus and PubMed) from November 2019 until February 2023. All studies that reported GIB events among COVID-19 patients were included. Results: 33 studies were selected and reviewed to estimate the prevalence of GIB. A total of 134,905 patients with COVID-19 were included in these studies, and there were 1458 episodes of GIB. The prevalence of GIB, in these 33 studies, ranges from 0.47% to 19%. This range of prevalence is justified by the characteristics of the COVID-19 patients. These characteristics are the severity of COVID-19, anticoagulant and other drug treatments, the selection of only patients with gastrointestinal manifestations, etc. The pooled prevalence of gastrointestinal bleeding was estimated to be 3.05%, rising to 6.2% when only anticoagulant patients were included. Conclusions: GIB in COVID-19 patients is not a rare finding, and its appropriate and immediate treatment is necessary as it can be life-threatening. The most common clinical findings are melena and hematemesis, which characterize upper GIB. Treatment can be conservative; however, endoscopic management of bleeding with embolization is deemed necessary in some cases.

The Value of Anticoagulation Management Combining Telemedicine and Self-Testing in Cardiovascular Diseases: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

No consensus has been established on the safety and effectiveness of out-of-hospital management of Vitamin K antagonists (VKA) therapy combining portable coagulometers and telemedicine. The present meta-analysis investigated the safety and effectiveness of this hybrid anticoagulants management model.

METHODS

The PubMed, Embase, Cochrane, and Web of Science databases were searched for papers published before May 1, 2022. To reduce bias, only randomized controlled trials were included. RevMan 5.3 (Cochrane) software was used to evaluate and analyze clinical outcomes, including the effectiveness and safety of patient management approaches, determined by the time in the therapeutic range (TTR) and occurrence of thrombotic and bleeding events.

RESULTS

Eight studies, comprising 3853 patients, were selected. The meta-analysis showed that anticoagulant management combining portable coagulometers and telemedicine significantly improved frequency of testing (mean difference [MD]= 12.95 days; 95% CI, 8.77-17.12; I²= 92%; P< 0.01) and TTR (MD= 9.50%; 95% CI, 3.16-15.85; I²= 87%; P< 0.01). Thromboembolism events were reduced (RR= 0.72; 95% CI, 0.51-1.01; I²= 0%; P= 0.05), but the results were not statistically significant. And no significant differences in major bleeding events, rehospitalization rate, mortality, or overall treatment cost existed between the two groups.

CONCLUSION

Although the safety of remote cardiovascular disease management is not superior to that of conventional outpatient anticoagulant management, it provides a more stable monitoring of coagulation status.

Developing a new sepsis screening tool based on lymphocyte count, international normalized ratio and procalcitonin (LIP score)

Exploring an effective sepsis screening tool that can be widely implemented is important for improving the prognosis of sepsis worldwide. This study aimed to develop a new simple screening tool for sepsis (LIP scoring system) that includes the peripheral blood lymphocyte count, international normalized ratio, and procalcitonin level. In a single-center, prospective, observational study, 444 acute sepsis inpatients and 444 nonsepsis inpatients were ultimately included based on the Sepsis-3 and exclusion criteria. The differences in the Lym, INR, PCT level and other clinical biomarkers were compared between the two groups. Univariable and multivariable logistic regression analyses and receiver operating characteristic analysis were used to establish a LIP screening tool for sepsis with a combination of biomarkers. The Kappa and McNemar tests were used to evaluate the differences between the LIP screening results (LIP score ≥ 3) and Sepsis-3 criteria (SOFA score ≥ 2). Logistic regression analysis showed that the lymphocyte count, INR, PCT level, platelets, neutrophil/lymphocyte ratio (NLR) and prothrombin time (PT) were independent risk factors for the development of sepsis. The ROC analysis showed that the lymphocyte count, INR, and PCT level had high area under the ROC curve values (AUROC (95% CI): Lym 0.84 (0.810-0.860), INR 0.921 (0.902-0.938), PCT level 0.928 (0.909-0.944)). The LIP tool had satisfactory screening efficacy for sepsis (sensitivity, 92.8%; specificity, 94.1%), and a LIP score equal to or greater than 3 points had good agreement with Sepsis-3 criteria in the diagnosis of sepsis (Kappa = 0862 in the Kappa test and P = 0.512 in the McNemar test). The LIP tool has satisfactory sensitivity and specificity for sepsis screening, and it can be used for rapid screening of patients with sepsis in outpatient and emergency departments or in economically underdeveloped areas with limited resources.

Combining portable coagulometers with the Internet: A new model of warfarin anticoagulation in patients following mechanical heart valve replacement

Heart valve replacement, as a safe and effective treatment for severe valvular heart disease, can significantly improve hemodynamics in patients. However, such patients then require lifelong anticoagulant therapy. Warfarin, a cheap and highly effective vitamin K antagonist, remains the major anticoagulant recommended for lifelong use following mechanical heart valve replacement. However, the effect of warfarin anticoagulant therapy is complicated by physiological differences among patients and non-compliance with treatment at different degrees. Effective management of warfarin therapy after heart valve replacement is currently an important issue. Portable coagulometers and the emergence of the Internet have provided new opportunities for long-term management of anticoagulation therapy, but the safety and affordability of this approach remain to be fully evaluated. This paper reviews recent progress on the use of portable coagulometers and the Internet in the management of warfarin anticoagulation therapy following mechanical heart valve replacement, which offers opportunities for reducing complications during postoperative anticoagulation and for facilitating patient compliance during follow-up.

Self-Administered, Remote Assessment of SARS-CoV-2 Seroprevalence in Health Care Workers

Background

Our objective was to safely and remotely assess longitudinal SARS-CoV-2 seroprevalence in at-risk health care workers at the onset of the epidemic.

Methods

Self-administered serologic testing was performed every 30 days up to 5 times using a point-of-care, lateral flow SARS-CoV-2 nucleocapsid IgG immunoassay in a cohort of at-risk health care workers (n = 339) and lower-risk controls (n = 100).

Results

Subjects were enrolled between 4/14/20–5/6/20 and most were clinicians (41%) or nurses (27%). Of 20 subjects who reported confirmed SARS-CoV-2 infection prior to (n = 5, 1%) or during the study (n = 15, 3%), half (10/20) were seropositive. Five additional subjects were seropositive and did not report documented infection. Estimated infection rates in health care workers did not differ from concurrent community rates.

Conclusions

This remotely conducted, contact-free study did not identify serologic evidence of widespread occupational SARS-CoV-2 infection in health care workers.

Development and validation of a mobile application based on a machine learning model to aid in predicting dosage of vitamin K antagonists among Indian patients post mechanical heart valve replacement

Patients who undergo heart valve replacements with mechanical valves need to take Vitamin K Antagonists (VKA) drugs (Warfarin, Nicoumalone) which has got a very narrow therapeutic range and needs very close monitoring using PT-INR. Accessibility to physicians to titrate drugs doses is a major problem in low-middle income countries (LMIC) like India. Our work was aimed at predicting the maintenance dosage of these drugs, using the de-identified medical data collected from patients attending an INR Clinic in South India. We used artificial intelligence (AI) - machine learning to develop the algorithm. A Support Vector Machine (SVM) regression model was built to predict the maintenance dosage of warfarin, who have stable INR values between 2.0 and 4.0. We developed a simple user friendly android mobile application for patients to use the algorithm to predict the doses. The algorithm generated drug doses in 1100 patients were compared to cardiologist prescribed doses and found to have an excellent correlation.

Semi-empirical anticoagulation model (SAM): INR monitoring during Warfarin therapy

The International Normalized Ratio (INR) monitoring is an essential component to manage thrombotic disease therapy. This study presents a semi-empirical model of INR as a function of time and assigned therapy (Warfarin, k-vitamin). With respect to other methodologies, this model is able to describe the INR using a limited number of parameters and is able to describe the time variation of INR described in the literature. The presented methodology showed great accuracy in model calibration [(trueness (precision)]: 0.2% (0.1%) to 1.2% (0.3%) for coagulation factors, from 5% (9%) to 9.7% (12%) for Warfarin-related parameters and 38% (40%) for K-vitamin-related parameters. The latter value was considered acceptable given the assumptions made in the model. It has two other important results: the first is that it was able to correctly estimate INR with respect to daily therapy doses taken from the literature. The second is that it introduces a single numeric semi-empirical parameter that is able to correlate INR/dose response to physiological and environmental condition of patients.

Clinical significance for combined coagulation indexes in epithelial ovarian cancer prognosis

Background

Increasing evidence supported an association between cancer and coagulation system. We aimed to identify prognostic values of coagulation biomarkers in epithelial ovarian cancer (EOC).

Methods

A retrospective study was conducted on patients who underwent optimal tumor debulking followed by platinum-based chemotherapy at our institution. The predictive value of coagulation variables was evaluated by receiver operating characteristic (ROC) curves. Through Cox hazards regression models, prognostic factors were determined for recurrence-free survival (RFS) and overall survival (OS). Survival curves were visualized by Kaplan–Meier method and compared through Log-rank analysis.

Results

We involved 482 EOC patients and followed up for 64 (range, 36–87) months. According to ROC curves, D-dimer and International normalized ratio (INR) had superior predictive value than other coagulation indexes, with area under curve (AUC) of 0.758 and 0.742. Patients were then stratified into three combined D-dimer and INR (DD-INR) groups based on the cut-off value of 0.97 mg/L and 0.86, respectively. Through regression analysis, we demonstrated that age (HR 1.273; 95%CI 1.048–2.047; p = 0.045), pathological grade (HR 1.419; 95% CI 1.102–2.491; p = 0.032), clinical stage (HR 2.038; 95%CI 1.284–3.768; p = 0.008), CA-125 (HR 1.426; 95%CI 1.103–1.894; p = 0.038) and DD-INR (HR 2.412; 95%CI 1.683–3.241; p = 0.009) were independent prognostic factors. Survival analysis showed that patients with higher DD-INR experienced poor survival (p = 0.0013 for RFS and p = 0.0068 for OS). Further subgroup analysis revealed that evaluated DD-INR was significantly associated with poor survival among patients with advanced stage (p = 0.0028 for RFS and p = 0.0180 for OS).

Conclusion

Our findings suggested that coagulation indexes, especially the combined DD-INR were promising biomarkers for prognosis stratification in EOC patients, especially those with advanced clinical stages.

World Heart Federation Roadmap on Atrial Fibrillation - A 2020 Update

The World Heart Federation (WHF) commenced a Roadmap initiative in 2015 to reduce the global burden of cardiovascular disease and resultant burgeoning of healthcare costs. Roadmaps provide a blueprint for implementation of priority solutions for the principal cardiovascular diseases leading to death and disability. Atrial fibrillation (AF) is one of these conditions and is an increasing problem due to ageing of the world's population and an increase in cardiovascular risk factors that predispose to AF. The goal of the AF roadmap was to provide guidance on priority interventions that are feasible in multiple countries, and to identify roadblocks and potential strategies to overcome them. Since publication of the AF Roadmap in 2017, there have been many technological advances including devices and artificial intelligence for identification and prediction of unknown AF, better methods to achieve rhythm control, and widespread uptake of smartphones and apps that could facilitate new approaches to healthcare delivery and increasing community AF awareness. In addition, the World Health Organisation added the non-vitamin K antagonist oral anticoagulants (NOACs) to the Essential Medicines List, making it possible to increase advocacy for their widespread adoption as therapy to prevent stroke. These advances motivated the WHF to commission a 2020 AF Roadmap update. Three years after the original Roadmap publication, the identified barriers and solutions were judged still relevant, and progress has been slow. This 2020 Roadmap update reviews the significant changes since 2017 and identifies priority areas for achieving the goals of reducing death and disability related to AF, particularly targeted at low-middle income countries. These include advocacy to increase appreciation of the scope of the problem; plugging gaps in guideline management and prevention through physician education, increasing patient health literacy, and novel ways to increase access to integrated healthcare including mHealth and digital transformations; and greater emphasis on achieving practical solutions to national and regional entrenched barriers. Despite the advances reviewed in this update, the task will not be easy, but the health rewards of implementing solutions that are both innovative and practical will be great.

Nursing self-efficacy for oral anticoagulant therapy management: Development and initial validation of a theory-grounded scale

AIM

This study aimed to develop and validate a nursing self-efficacy scale for OAC management (SE-OAM).

BACKGROUND

Oral anticoagulant therapy (OAC) requires specific nursing competencies. Given that self-efficacy acts as a proxy assessment of nursing competence, its measurement is pivotal for addressing educational programs to enhance nursing competence in managing OAC. Thus far, the measurement of self-efficacy in OAC is undermined by the unavailability of valid and reliable tools.

METHODS

A multi-method and multi-phase design was adopted: Phase one was a methodological study encompassing developmental tasks for generating items. Phase two comprised the validation process for determining the content validity, construct and concurrent validity, and internal consistency through two cross-sectional data collections.

RESULTS

In total, 190 nurses were enrolled for determining the psychometric structure of the SE-OAM through an exploratory approach, and 345 nurses were subsequently enrolled to corroborate its most plausible factor structure derived from the exploratory analysis. The SE-OAM showed evidence of face and content validity, adequate construct, concurrent validity, good internal consistency, and stability. The final version of the scale encompassed 21 items kept by five domains: clinical management, care management, education, clinical monitoring, and care monitoring.

CONCLUSIONS

The SE-OAM showed evidence of initial validity and reliability, fulfilling a current gap in the availability of tools for measuring nursing self-efficacy in managing OAC. SE-OAM could be strategic for performing research to improve the quality of OAC management by enhancing nursing self-efficacy.

Patients' adherence to oral anticoagulants therapy: Comparison between vitamin K antagonists and direct oral anticoagulants

BACKGROUND

Patient's adherence to oral anticoagulant therapy is essential to prevent and treat thrombotic events.

METHODS

To assess the patients' adherence Morisky Medication Adherence Scale 8-items was used. The target population included 785 consecutive outpatients, of whom 384 were on Vitamin K Antagonists and 401 on Direct Oral Anticoagulants. Moreover, we evaluate which variable among age, gender, having experienced a thrombotic episode, time in the therapeutic range for patients on Vitamin K Antagonists, being naive and once versus twice daily drug assumption for patients on Direct Oral Anticoagulants, could affect adherence to therapy.

RESULTS

Morisky Medication Adherence Scale 8-items score was 8 in both groups. The intentional non-adherence obtained the lowest score while the unintentional non-adherence is the most frequent problem in patients treated with either Vitamin K Antagonists or Direct Oral Anticoagulants. Age > 75 years, male gender, having experienced a thrombotic episode, being naive and assuming Direct Oral Anticoagulants twice a day were significantly associated with a higher risk to forget assuming the oral anticoagulant, to have more difficulty in remembering to take it or to bring it in case of travel or leaving home. A low percentage of time in therapeutic range was associated with a not regularly assumption of the anticoagulants.

CONCLUSION

Patients treated with Vitamin K Antagonists or Direct Oral Anticoagulants show a good adherence and persistence to their oral anticoagulant therapy. Several factors have been identified to affect patients' adherence and deserve a careful attention by the doctors at the Anticoagulation Clinic.

Massage of the Hepatoduodenal Ligament Recovers Portal Vein Flow Immediately After the Pringle Maneuver in Hepatectomy

BACKGROUND

The Pringle maneuver is often used in liver surgery to minimize bleeding during liver transection. Many authors have demonstrated that intermittent use of the Pringle maneuver is safe and effective when performed appropriately. However, some studies have reported that the Pringle maneuver is a significant risk factor for portal vein thrombosis. In this study, we evaluated the effectiveness of portal vein flow after the Pringle maneuver and the impact that massaging the hepatoduodenal ligament after the Pringle maneuver has on portal vein flow.

MATERIALS AND METHODS

Patients treated with the Pringle maneuver for hepatectomies performed to treat hepatic disease at our hospital between August 2014 and March 2019 were included in the study (N = 101). We divided these patients into two groups, a massage group and nonmassage group. We measured portal vein blood flow with ultrasonography before and after clamping of the hepatoduodenal ligament. We also evaluated laboratory data after the hepatectomy.

RESULTS

Portal vein flow was significantly lower after the Pringle maneuver than before clamping of the hepatoduodenal ligament. The portal vein flow after the Pringle maneuver was improved following massage of the hepatoduodenal ligament. After hepatectomy, serum prothrombin time was significantly higher and serum C-reactive protein was significantly lower in the massage group than in the nonmassage group.

CONCLUSION

Massaging the hepatoduodenal ligament after the Pringle maneuver is recommended in order to quickly recover portal vein flow during hepatectomy and to improve coagulability.

The Clotting Trigger Is an Important Determinant for the Coagulation Pathway In Vivo or In Vitro-Inference from Data Review

Blood coagulation comprises a series of enzymatic reactions leading to thrombin generation and fibrin formation. This process is commonly illustrated in a waterfall-like manner, referred to as the coagulation cascade. In vivo, this "cascade" is initiated through the tissue factor (TF) pathway, once subendothelial TF is exposed and bound to coagulation factor VII (FVII) in blood. In vitro, a diminutive concentration of recombinant TF (rTF) is used as a clotting trigger in various global hemostasis assays such as the calibrated automated thrombogram, methods that assess fibrin turbidity and fibrin viscoelasticity tests such as rotational thromboelastometry. These assays aim to mimic in vivo global coagulation, and are useful in assessing hyper-/hypocoagulable disorders or monitoring therapies with hemostatic agents. An excess of rTF, a sufficient amount of negatively charged surfaces, various concentrations of exogenous thrombin, recombinant activated FVII, or recombinant activated FIXa are also used to initiate activation of specific sub-processes of the coagulation cascade in vitro. These approaches offer important information on certain specific coagulation pathways, while alterations in pro-/anticoagulants not participating in these pathways remain undetectable by these methods. Reviewing available data, we sought to enhance our knowledge of how choice of clotting trigger affects the outcome of hemostasis assays, and address the call for further investigations on this topic.

Bleeding risk associated with combination thromboprophylaxis therapy is low for patients with coronary artery aneurysms after Kawasaki disease

BACKGROUND

Kawasaki disease (KD) may lead to coronary artery aneurysms (CAA) with potential for thrombosis. We aimed to determine the bleeding risk during thromboprophylaxis regimens with dual and triple therapy.

METHODS

KD patients with medium to large CAAs receiving combination thromboprophylaxis therapy (dual or triple therapy with acetylsalicylic acid (ASA), clopidogrel, low molecular weight heparin (LMWH) or warfarin) were reviewed (1979-2017). Treatment periods <30 days were excluded. Bleeding events were classified using the Bleeding Academic Research Consortium (BARC) Score. The incidence of bleeding events per patient year of exposure was determined for each regimen.

RESULTS

n = 98 of 3022 KD (23 females:75 males) were included. Median age at diagnosis was 2.6 years (IQR: 0.6-6.2), median maximum CAA z-score was 18.0 (range: 5-65.5, IQR: 10.8-28.0, m = 6) and median follow-up duration was 6.5 years (IQR: 2.5-20.2). The incidence of type ≥2 bleeds per patient-year for each regimen was 0 (ASA + clopidogrel+LMWH), 0.03 (ASA + clopidogrel), 0.06 (ASA + warfarin), 0.06 (ASA + clopidogrel+warfarin), and 0.1 (ASA + LMWH) in ascending order. 31 bleeding events requiring medical attention (type ≥2) occurred in 30 patients (median age 7.8 years). Of the 17 type ≥2 bleeds on warfarin with an International Normalised Ratio (INR) available, 13 occurred with an INR >3. For patients receiving triple therapy (dual antiplatelet with anticoagulant), there were 57 bleeding events over 20 treatment periods.

CONCLUSIONS

The overall bleeding risk was low in KD patients receiving combination thromboprophylaxis, and not significantly different across all regimens. Type ≥2 bleeding events that occurred on warfarin were most frequently associated with high INR values.

Benefit of Self-Managed Anticoagulation in Patients with Left Ventricular Assist Device

BACKGROUND

 The exact monitoring of the therapeutic-range international normalized ratio (INR) after left ventricular assist device (LVAD) implantation is an important aim to reduce the risk of thrombosis or bleeding complications. Service providers offer a telemedical anticoagulation service (CS).

METHODS

 We compared LVAD patients using the CS (n = 15) to those who received regular medical care (RMC; n = 15) to investigate if telemedicine supervision increased the INR-specific time in the therapeutic range (TTR) during anticoagulation. All patients received self-management training for phenprocoumon medication according to their INR value. INR values were documented for 12 months. A survey (scale: 1 = not satisfied and 10 = very satisfied) was used to determine patient's satisfaction and psychological well-being.

RESULTS

 A total of 1,798 INR measurements were analyzed. The TTR_Rosendaal was higher in patients undergoing RMC (78.1 ± 14.3%) compared with that in patients using the CS (58.3 ± 28.0%, p = 0.03). The patient's satisfaction with the coagulation setting at the beginning of the study (RMC: 6.7 ± 3.1, CS: 7.2 ± 3.0, p = 0.74) and psychological wellbeing (RMC: 6.5 ± 1.9, CS: 6.5 ± 2.7, p = 0.97) were comparable between both groups.

CONCLUSION

 We found that INR self-management is superior regarding the efficiency of post-LVAD anticoagulation therapy when compared with telemedical (CS)-based INR management in a small study cohort. Intensive training by experienced staff was able to replace CS.

Thrombosis centres and AVKs monitoring in COVID-19 pandemic

Vitamin K-Antagonists (VKAs) are the treatment of choice in patients with indications other than atrial fibrillation and venous thromboembolism. Moreover, some patients still assume VKAs refusing to change their therapy when direct oral anticoagulants (DOACs) are properly indicated. The COVID-19 pandemic has completely changed our lives, nullifying inter-personal relationships to avoid contagion, making difficult the VKAs monitoring. We describe the re-organization of our thrombosis centre (TC) as an example on how to face the emergency due to the COVID-19 pandemic. In the first phase, to avoid overcrowding at the TC, we planned to increase the interval time between INRs checks and to encourage blood sampling at home, especially for elderly patients. Moreover, precise scheduled blood sampling was also organized while telephone and email counselling were guaranteed by two doctors of the TC. In the second phase, to reduce the number of patients who daily attended our TC a switch from VKAs to DOACs was carried out, if no contraindications were identified. In the third phase, to protect patients, healthcare staff and hospital from COVID-19 widespread, telemedicine was strengthened. We tried to extend self-testing at home by means of portable coagulometers to as more patients as possible. To avoid patients staying or coming back to the TC an ad hoc web platform for sending the therapeutic dose adjustment and the next scheduled appointment was developed. The TC re-organization allowed us to monitor anticoagulated patients respecting personal isolation and security measures to avoid possible COVID-19 contagion.

Functionally Significant Coumarin-Related Variant Alleles and Time to Therapeutic Range in Chilean Cardiovascular Patients

Despite the development of new oral agents over the last decade, vitamin K antagonists (VKAs) remain the most widely used anticoagulants for treating and preventing thromboembolism worldwide. In Chile, the Ministry of Health indicates that acenocoumarol should be used in preference to any other coumarin. Complications of inappropriate dosing are among the most frequently reported adverse events associated with this medication. It is well known that polymorphisms in pharmacokinetic and pharmacodynamic proteins related to coumarins (especially warfarin) influence response to these drugs. This work analyzed the impact of CYP2C19*2 (rs4244285), CYP1A2*1F (rs762551), GGCx (rs11676382), CYP2C9*2 (rs1799853), CYP2C9*3 (rs1057910), CYP4F2 (rs2108622), VKORC1 (rs9923231), VKORC1 (rs7294), CYP3A4*1B (rs2740574), and ABCB1 (rs1045642) polymorphisms on time to therapeutic range for oral anticoagulants in 304 Chilean patients. CYP2C9*3 polymorphisms were associated with time to therapeutic range for acenocoumarol in Chilean patients, and the CYP4F2 TT genotype, MDR1 A allele, CYP1A2 A allele, and CYP3A4T allele are promising variants that merit further analysis. The presence of polymorphisms explained only 4.1% of time to therapeutic range for acenocoumarol in a multivariate linear model. These results improve our understanding of the basis of ethnic variations in drug metabolism and response to oral anticoagulant therapy. We hope that these findings will contribute to developing an algorithm for VKA dose adjustment in the Chilean population in the near future, decreasing the frequency of stroke, systemic embolism, and bleeding-related adverse events.

Performance of the LumiraDx Platform INR Test in an Anticoagulation Clinic Point-of-Care Setting Compared With an Established Laboratory Reference Method

Vitamin K antagonists, such as warfarin, have a narrow therapeutic window; patients on these therapies therefore require regular international normalized ratio (INR) monitoring to maintain optimal dosing. This involves periodic checks and laboratory testing using venepuncture, which are often perceived as a burden. This study aimed to determine the accuracy and precision of the LumiraDx INR Test, a new point-of-care in vitro diagnostic platform, in an anticoagulation clinic setting. In this observational, cross-sectional study, precision of the LumiraDx INR Test was assessed using paired replicate samples (n = 366) and 3 test strip lots. Accuracy was determined by comparing capillary blood INR, ascertained by the LumiraDx INR Test, with venous plasma INR, measured by the laboratory reference instrument, the IL ACL ELITE Pro. Furthermore, INR was assessed across a range of hematocrit (25%-55%). In addition, feedback was collected from health-care professionals via a self-completed questionnaire. This trial was registered at ClinicalTrials.gov (NCT03682419). The precision (% coefficient of variation) of the LumiraDx INR Test was <4 when samples were applied by direct application or via a capillary transfer pipette, as well as between test strip lots. Accuracy of the LumiraDx INR Test, across the INR range of 0.8 to 7.5, was confirmed by a strong correlation of 0.965 (95% confidence interval: 0.959-0.970) when compared with the IL ACL ELITE Pro, which was maintained across the hematocrit range. Feedback from health-care professionals indicated that the instructions given by the system were easy to follow. In conclusion, the strong agreement between the LumiraDx Platform INR point-of-care test and the IL ACL ELITE Pro laboratory reference system, as well as between the different application methods and test lots, indicates that it can provide a rapid, accurate, and reliable INR analysis.

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.

Point-of-care testing in primary care: A systematic review on implementation aspects addressed in test evaluations

OBJECTIVES

There are numerous point-of-care tests (POCTs) available on the market, but many of these are not used. This study reviewed literature pertaining to the evaluation/usage of POCTs in primary care, to investigate whether outcomes being reported reflect aspects previously demonstrated to be important for general practitioners (GPs) in the decision to implement a POCT in practice.

METHODS

Scopus and Medline were searched to identify studies that evaluated a POCT in primary care. We identified abstracts and full-texts consisting of applied studies (eg trials, simulations, observational studies) and qualitative studies (eg interviews, surveys). Data were extracted from the included studies, such as the type of study, the extent to which manufacturers were involved in the study, and the biomarker/assay measured by the test(s). Studies were evaluated to summarise the extent to which they reported on, amongst others, clinical utility, user-friendliness, turnaround-time and technical performance (aspects previously identified as important).

RESULTS

The initial search resulted in 1398 publications, of which 125 met the inclusion criteria. From these studies, 83 POCTs across several disease areas (including cardiovascular disease, venous thromboembolism and respiratory-tract-infections) were identified. There was an inconsistency between what is reported in the studies and what GPs consider important. GPs perceive clinical utility as the most important aspect, yet this was rarely included explicitly in test evaluations in the literature, with only 8% of evaluations incorporating it in their analysis/discussion.

CONCLUSIONS

This review showed that, despite the growing market and development of new POCTs, studies evaluating such tests fail to report on aspects that GPs find important. To ensure that an evaluation of a POCT is useful to primary care clinicians, future evaluations should not only focus on the technical performance aspects of a test, but also report on the aspects relating to the clinical utility and risks.

A simple and compact smartphone-based device for the quantitative readout of colloidal gold lateral flow immunoassay strips

Colloidal gold lateral flow immunoassay strips (AuNPs-LFIS) have been widely applied as qualitative diagnostic tools for point-of-care tests (POCT). If strip readers were incorporated, their use could be extended to quantitative analysis. However, their cost and non-portability render commercial strip readers unavailable for use in either home testing, community or rural hospital diagnosis. This is particularly true for on-site testing. Here, a smartphone-based reader was designed and 3D-printed for quantitatively assess AuNPs-LFIS. The basic principle of the devise was relying on a smartphone's ambient light sensor (SPALS). This sensor was harnessed to measure the transmitted light intensities originating from the T-lines on the strips, the transmitted light intensities vary with concentration of AuNP on the T-lines. To validate this approach, our newly developed smartphone's ambient light sensor-based reader (SPALS-reader) was used to readout AuNPs-LFIS of three analytical targets: cadmium ion (Cd²⁺; limit of detection (LOD) was 0.16 ng/mL), clenbuterol (CL; LOD was 0.046 ng/mL), and porcine epidemic diarrhea virus (PEDV; LOD was 0.055 μg/mL). The result showed good consistency with the results of conventional image analysis approaches, indicating that the smartphone-based device is appropriate for use in AuNPs-LFIS readouts. Compared with the traditional analysis method, the developed AuNPs-LFIS reader is easier operated, lower cost and more portable, which provided an on-site quantitative analysis tool for AuNPs-LFIS and enhances the applied range of AuNPs-LFIS.

Sclerotherapy for intramuscular vascular malformations: A single-center experience

BACKGROUND

Vascular malformations isolated to skeletal muscles are rare and often debilitating due to pain and very challenging to treat. Multi-modal management options include compression garments, medical therapy, sclerotherapy, and surgical resection.

METHODS

A retrospective review of patients who underwent sclerotherapy for intramuscular venous malformations (IVM) between 2008 and 2016 was performed. Demographics, indications, and clinical follow-up were analyzed.

RESULTS

Twenty patients underwent sclerotherapy for IVM. Six males and 14 females underwent 58 procedures. All patients presented with pain and were treated initially with compression garments. Median age at first treatment was 13years (+/- 5.06years). Initial protocol consisted of 2 sclerotherapy procedures with sodium tetradecyl sulfate (STS) within a 2-3month interval. Median volume of the lesion was 40cm³ (+/- 28.7), mostly located in the lower extremities (15/20). Median number of treatments was 2 (+/- 1.95). Treatment prior to puberty resulted in a median symptom-free time of 4years (+/- 2.18), while after puberty resulted in a symptom-free time of 2years (+/- 2.28). Two patients had an underlying coagulopathy and were admitted for observation and peri-procedural Lovenox. No procedure related complications were noted with a median follow-up of 4years (+/- 2.27).

CONCLUSION

IVMs are rare but can be incapacitating secondary to pain. Sclerotherapy is a useful minimally invasive procedure generally requiring at least two consecutive treatments. Treatment of patients prior to puberty appears to provide a more durable result, and surgical resection may be avoided.

TYPE OF STUDY

retrospective.

LEVEL OF EVIDENCE

IV.

Level of agreement between laboratory and point-of-care prothrombin time in patients after stopping or continuation of acenocoumarol anticoagulation: A comparison of diagnostic accuracy

BACKGROUND

Procedures requiring optimisation of the coagulation status of patients using vitamin K antagonists are frequently postponed due to the late availability of laboratory international normalised ratio (INR) test results. A point-of-care (POC) alternative may facilitate early decision-making in peri-operative patients.

OBJECTIVES

To assess the level of agreement between the POC-INR and the laboratory INR in patients who continue or stop vitamin K antagonists to determine whether the POC test may be a good alternative to the laboratory INR.

DESIGN

Study of diagnostic accuracy.

SETTING

Single-centre study at Zaans Medical Centre, The Netherlands.

PATIENTS

Included patients were scheduled for cardioversion (these continued taking vitamin K antagonists), or a surgical procedure (these stopped taking vitamin K antagonists).

MAIN OUTCOME MEASURES

The level of agreement and clinical acceptability of the laboratory and POC-INR results, evaluated by Bland-Altman analysis and error grid analysis.

RESULTS

The surgical and cardioversion groups consisted of 47 and 46 patients, respectively. The bias in the INR in the surgical group was -0.12 ± 0.09 with limits of agreement of -0.29 to 0.05, whereas the cardioversion group showed a bias in the INR of -0.22 ± 0.36 with limits of agreement from -0.93 to 0.48. The percentage errors between methods in the surgical and cardioversion groups were 16 and 21%, respectively. Error grid analysis showed that the diagnostic accuracy of the POC prothrombin time is clinically acceptable as the difference did not lead to a different clinical decision in the surgical group with INR values less than 1.8.

CONCLUSION

The current study shows a good level of agreement and clinical accuracy between the laboratory and POC-INR in patients who stopped anticoagulation intake for surgery. However, in patients who continued their anticoagulation therapy, the agreement between the two methods was less accurate.

Portable coagulometer for vitamin K-antagonist monitoring: the patients' point of view

PURPOSE

The aim of this study was to know the patients' point of view on the monitoring of vitamin K-antagonist (VKA) therapy by means of a point of care testing (POCT), ie, using a portable coagulometer by self-testing at home. At first, patients had prothrombin time (PT) international normalized ratio (INR) monitoring at a thrombosis center; afterward, they were shifted to self-testing at home. An interview was done to evaluate the patients' point of view on the two monitoring periods.

PATIENTS AND METHODS

A total of 92 oral anticoagulated patients were enrolled. The questionnaire contained nine questions that elicited a maximum of five closer answers that were arranged in increasing levels of satisfaction: very little, little, enough, much and completely. Percentage of time in therapeutic range (TTR) and adverse events were compared during the two periods of conventional monitoring and self-testing.

RESULTS

The period of conventional monitoring was shorter than that of self-testing (p<0.0001), and the median TTR was satisfactory but lower than that of self-testing (p<0.0001). A total of 85% of the patients were satisfied with self-testing at home. In all, 83% and 73% (p=0.06) of patients felt comfortable about side effects while measuring the PT INR at both home and the thrombosis center, respectively. During the self-testing period, quality of life was improved in 87% of the patients. The cost of test strips was medium-high for 89% of the patients, and 75% of them stated that it was worth improving their quality of life. A switch from VKA to a direct oral anticoagulant (DOAC) was proposed to 24% of the patients, but 68% of them declined because they felt more comfortable monitoring their oral anticoagulant therapy by POCT.

CONCLUSION

VKA monitoring using POCT at home may play a role in improving the patients' quality of life and may be considered as an alternative to the use of DOAC at least in certain settings of patients.