International Normalized Ratio Measurements Research Articles

Evaluation of a multicomponent integrated intervention to improve the quality of care for anticoagulated frail older adults in a home care system in the city of Buenos Aires

Introduction: Anticoagulation in older adults is a real challenge due to the presence of health conditions that can alter the adequate control of the patient. Older adults confined to home probably could not attend outpatient medical consultations. On many occasions, the monitoring of the patient's health process at home is carried out by a health professional who does not monitor the anticoagulant treatment (e.g. due to lack of experience of the professional).
 For this reason, the home care section of the Italian Hospital of Buenos Aires (HIBA) created an interdisciplinary team for the telephone follow-up of anticoagulated patients in that area.
 Objectives: Describe the effect of a multicomponent intervention to improve the quality of anticoagulation therapy in frail elderly patients in the home care system of the HIBA.
 Methods: Prospective pragmatic evaluation study of a multiple intervention with a before-after design. Variables were analyzed from secondary databases 6 months before and after the intervention. The unit of analysis was the patient acting as his own control. The setting was the home medicine section of HIBA. We included patients aged 65 years or over receiving dicumarinics with home care and follow-up by a doctor with fewer tools in the management of anticoagulants and with communication barriers. Telephone contacts with patients were made by family physicians. A hematologist was consulted whenever necessary. Pharmacists sent pills of vitamin K with educational brochures to the patient's home. Health and social counsellors contacted patients in complex cases to strengthen education. Reasons for withdrawal of the program were: death, hospitalization, termination of the home care service, follow-up of the treatment by a hematologist or anticoagulant suspension.
 Results: Analysis of the data was performed before the intervention (June 1, 2021 to November 30, 2021) and after the intervention ( December 1, 2021, to June 30, 2022), 41 patients were included, 78% were female, average age was 87 years. The mean of basic activities of daily living was 3.35, the average of the Percentage of International Normalized Ratio Measurements in Range (PINRR) in the pre intervention was 31% and 49% in the post. There weren't thrombotic events and the average of bleeding events was 6% in the pre and 0% in the post, extreme values of INR (>6) in the pre was 3% and in the post 0,5%. Finally the mean of emergency medical consultations was 1,15 in the pre and 0,29 in the post.
 Conclusions: The present work consists in the analysis of an elderly population highly dependent on activities of daily living. The data shows a possible tendency of reduction in the number of emergency medical consultations, bleeding events and improvement in the PINRR. As next steps we propose evaluate patients' satisfaction with the intervention, analize long-term results as the program works in time and generate institutional tools to deprescribe.
 
 

The Concordance between Laboratory and POCT INR and the Value of Bedside Measurement of INR in Patients on Warfarin Undergoing Dental Procedures: A Prospective Cohort Study

Introduction: Patients on anticoagulation particularly warfarin suffers when they have a dental problem that requires intervention. Most of dentists worry and refuse to perform procedures on patients on warfarin because of the risk of bleeding and request the availability of international normalized ratio (INR) results before procedure which can delay the procedure and add another burden on the patient particularly who live away from the treating center. Objective: To evaluate the efficacy and the value of using point of care testing (POCT) (INR) in patients on warfarin undergoing dental procedures. We also had analyzed the frequency and severity of dental bleeding in patients on warfarin therapy and the concordance between Laboratory based INR and POCT INR. This is the first interim analysis on ongoing prospective study. Methods: A cohort study of 30 patients on chronic use of anticoagulation therapy with warfarin for different clinical indications who planned to undergo dental procedures at a teaching hospital in Saudi Arabia. The patients' demographic and clinical characteristics, type and severity of bleeding, and INR measured by both HemoChrone (POCT) and prothrombin time (PT) were performed at same time. Descriptive statistics, paired samples statistics, correlations, and analysis of variance (ANOVA) were performed. Results: The sample consisted of 60% females, with a mean age of 49.9 (SD 13.3) years. The most common indications for warfarin therapy were mechanical aortic valve replacement (56.7%), atrial fibrillation (13.3%), and atrial flutter (16.7%). Before the procedure, the mean Laboratory INR was 2.6 (SD 0.6) and the mean HemoChrone POCT INR was 2.8 (SD 0.8). There was a significant positive correlation between the two methods (r = 0.81, p < 0.001). There was no significant difference in the INR and type of bleeding, dentist performed the procedure, or dose of warfarin. There was no correlation between the Bleeding severity or type and the INR level in patients undergoing different dental procedures. Even among those with HemoChrone POCT INR > 3, which is considered high and increases the risk of bleeding, there was no significant correlation with bleeding. Conclusion: These results imply that warfarin therapy can be safely continued for most dental procedures without increasing the risk of bleeding regardless of the INR results. The HemoChrone POCT INR is a dependable and practical method to monitor the effect of warfarin in dental settings which can reassure the dentists before procedure. Figure 1: The concordance between Laboratory and POCT INR

PB1149 International Normalised Ratio Measurement During Bridging with Low Molecular Weight Heparin

PB1149 International Normalised Ratio Measurement During Bridging with Low Molecular Weight Heparin

Efficacy of Warfarin Therapy Guided by Pharmacogenetics: A Real-world Investigation Among Han Taiwanese

The anticoagulation activity of warfarin in populations with CYP2C9, VKORC1, and CYP4F2 variants differs between individuals and is correlated with poor international normalized ratio (INR) control. Pharmacogenetics-guided warfarin dosing has been successfully developed for patients with genetic variations in recent years. However, few real-world data have been used to investigate the INR and warfarin dosage and the time to target INR. This study examined the largest collection of genetic and clinical real-world data related to warfarin to provide further evidence supporting the benefits of pharmacogenetics in clinical outcomes. We retrieved a total of 69,610 INR-warfarin records after the index date from 2,613 patients in the China Medical University Hospital database between January 2003 and December 2019. Each INR reading was obtained from the latest laboratory data after the hospital visit date. Patients with a history of malignant neoplasms or pregnancy before the index date were excluded, as were patients without data on INR measurements after the fifth day of prescription, genetic information, or gender variables. The primary outcomes were the INR and warfarin dosage during days 7, 14, 28, 56, and 84 after prescription. The secondary outcome was the time required to reach the INR ranges of 1.5 to 3.0 and >4.0. A total of 59,643 INR-warfarin records from 2188 patients were retrieved. The average INR was higher for homozygous carriers of the minor allele at CYP2C9 and VKORC1 during the first 7 days (1.83 [1.03] [CYP2C9*1] and 2.46 [1.44] [CYP2C9*3], P < 0.001; 1.39 [0.36] [rs9923231 G/G], 1.55 [0.79] [rs9923231 G/A], and 1.96 [1.13] [rs9923231 A/A], P < 0.001) than for the wild-type allele. These patients with variants required lower warfarin doses than those with the wild-type allele during the first 28 days. CYP4F2 variant patients seemed to require higher doses of warfarin than those in the wild-type group; however, no significant difference in the average INR was observed (1.95 [1.14] [homozygous V433 carriers], 1.78 [0.98] [heterozygous V433M carriers], and 1.66 [0.91] [homozygous M433 carriers], P=0.016). Our study indicates that genetic variants in the Han population may enhance warfarin responsiveness, which holds clinical relevance. An increased warfarin dosage was not linked to a shorter time to therapeutic INR between CYP4F2 variant patients and those with a wild-type allele. Assessing CYP2C9 and VKORC1 genetic polymorphisms before initiating warfarin treatment in real-world practice is essential for potentially vulnerable patients and is likely to optimize therapeutic dosing.

The international normalised ratio to monitor coagulation factor production during normothermic machine perfusion of human donor livers

BackgroundNormothermic machine perfusion (NMP) of donor livers allows for new diagnostic and therapeutic strategies. As the liver produces most of the haemostatic proteins, coagulation assays such as the International Normalised Ratio (INR) performed in perfusate may be useful to assess hepatocellular function of donor livers undergoing NMP. However, high concentrations of heparin and low levels of fibrinogen may affect coagulation assays. MethodsThirty donor livers that underwent NMP were retrospectively included in this study, of which 18 were subsequently transplanted. We measured INRs in perfusate in presence or absence of exogenously added fibrinogen and/or polybrene. Additionally, we prospectively included 14 donor livers that underwent NMP (of which 11 were transplanted) and measured INR using both a laboratory coagulation analyser and a point-of-care device. ResultsIn untreated perfusate samples, the INR was above the detection limit in all donor livers. Addition of both fibrinogen and polybrene was required for adequate INR assessment. INRs decreased over time and detectable perfusate INR values were found in 17/18 donor livers at the end of NMP. INR results were similar between the coagulation analyser and the point-of-care device, but did not correlate with established hepatocellular viability criteria. ConclusionsMost of the donor livers that were transplanted showed a detectable perfusate INR at the end of NMP, but samples require processing to allow for INR measurements using laboratory coagulation analysers. Point-of-care devices bypass this need for processing. The INR does not correlate with established viability criteria and might therefore have additional predictive value.

Accuracy and Precision of Point-of-Care International Normalized Ratio in Patients With Liver Disease.

To determine if the CoaguChek XS Pro Point-of-Care (POC) device can accurately and precisely measure the international normalized ratio (INR) compared with the gold standard laboratory INR in pediatric and adult patients with liver disease. This prospective cohort study included 15 pediatric patients without liver disease, 13 pediatric patients with liver disease, and 17 adult patients with liver disease. The accuracy of the POC INR values was determined using the correlation and Bland-Altman limits of agreement. The accuracy of the coagulometer INR was assessed by calculating the proportion of POC INR measurements that were ≤15% of their corresponding laboratory INR. A comparison of INR measurements showed an excellent correlation in pediatric patients without liver disease ( r = 0.82), pediatric patients with liver disease ( r = 0.89), and adult patients with liver disease ( r = 0.96). Fourteen (93%) POC INR values were ≤15% in pediatric patients without liver disease from its paired laboratory INR. All 13 paired measurements were ≤15% in pediatric patients with liver disease. In adult patients with liver disease, 12 (71%) POC INR values were ≤15% of their paired laboratory INR. In patients with liver disease, the CoaguChek XS Pro provides an accurate measure of the INR compared to laboratory INR measurements.

Leukocyte surface expression of the endoplasmic reticulum chaperone GRP78 is increased in severe COVID-19.

Hyperinflammation present in individuals with severe COVID-19 has been associated with an exacerbated cytokine production and hyperactivated immune cells. Endoplasmic reticulum stress leading to the unfolded protein response has been recently reported as an active player in inducing inflammatory responses. Once unfolded protein response is activated, GRP78, an endoplasmic reticulum-resident chaperone, is translocated to the cell surface (sGRP78), where it is considered a cell stress marker; however, its presence has not been evaluated in immune cells during disease. Here we assessed the presence of sGRP78 on different cell subsets in blood samples from severe or convalescent COVID-19 patients. The frequency of CD45+sGRP78+ cells was higher in patients with the disease compared to convalescent patients. The latter showed similar frequencies to healthy controls. In patients with COVID-19, the lymphoid compartment showed the highest presence of sGRP78+ cells versus the myeloid compartment. CCL2, TNF-α, C-reactive protein, and international normalized ratio measurements showed a positive correlation with the frequency of CD45+sGRP78+ cells. Finally, gene expression microarray data showed that activated T and B cells increased the expression of GRP78, and peripheral blood mononuclear cells from healthy donors acquired sGRP78 upon activation with ionomycin and PMA. Thus, our data highlight the association of sGRP78 on immune cells in patients with severe COVID-19.

The treatment indication affects the time in therapeutic range

Objectives: This study aimed to compare the efficacy and safety of the treatment in patients with deep vein thrombosis (DVT) and mechanical mitral valve replacement (MVR) who were treated with warfarin for different indications. Patients and methods: A total of 536 patients (314 males, 222 females; mean age: 55.6±10.8 years; range, 18 to 89 years) were retrospectively reviewed between January 2016 and January 2020. The patients were evaluated in two groups: 273 DVT patients (149 males, 124 females; mean age: 56.7±11.3 years) who received long-term therapy (six months) and 263 mechanical MVR patients (165 males, 98 females; mean age: 56.2±9.4 years). Both groups were compared in terms of the percentage of time in the therapeutic range (TTR), the time to reach the target international normalized ratio (INR), and warfarin related complications. Results: The number of total hospital visits and total INR measurements for six months in the MVR group was statistically significantly higher than in the DVT group (p&lt;0.001). The duration and percentage of TTR in the first three and six months of the MVR group were statistically significantly higher than the DVT group (p&lt;0.05). Conclusion: More MVR patients remained in the therapeutic range than DVT patients due to the frequent hospital visits of these patients for various reasons; thus, it may be beneficial to increase the frequency of follow-up examinations or measurements of INR in patients who have started warfarin treatment for an indication other than valve replacement.

Time in therapeutic range for virtual anticoagulation clinic versus in-person clinic during the COVID-19 pandemic: a crossover study.

COVID-19 infection affects the quality of the medical services globally. The pandemic required changes to medical services in several institutions. We established a virtual clinic for anticoagulation management during the pandemic using the Whatsapp application. Compare anticoagulation management quality in virtual versus in-person clinics. A retrospective crossover study SETTINGS: Specialized cardiac care center PATIENTS AND METHODS: The study included patients who presented to Prince Sultan Cardiac Center in Riyadh for anticoagulation management during the pandemic from March 2020 to January 2021. We compared time in therapeutic range (TTR) in the same patients during virtual and in-person clinics. All international normalized ratio (INR) measures during the virtual clinic visits and prior ten INR measures from the in-person clinic were recorded. Patients who had no prior follow-up in the in-person clinic were excluded. TTR calculated using the Rosendaal method. 192 patients RESULTS: The mean age was 58.6 (16.6) years and 116 (60.4%) were males. Patients were diagnosed with atrial fibrillation (n=101, 52.6%), mechanical mitral valve (n=88, 45.8%), mechanical aortic valve (n=79, 41%), left ventricular thrombus (n=5, 2.6%) and venous thromboembolism (n=8, 4.2%). Riyadh residents represented 56.7% of the study population (n=93). The median (IQR) percent TTR was 54.6 (27.3) in the in-person clinic versus 50.0 (33.3) (P=.07). Virtual clinic results were comparable to in-person clinics for anticoagulation management during the COVID-19 pandemic. Number of INR measures during the virtual clinic visits, retrospective nature and single-center experience. None.

Oral anticoagulants, time in therapeutic range and renal function over time in real-life patients with atrial fibrillation and chronic kidney disease

AimsTo describe the use of warfarin and direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) and chronic kidney disease (CKD), to evaluate changes in renal function over time...

Best quality indicator of vitamin K antagonist therapy to predict mortality and bleeding in haemodialysis patients with atrial fibrillation.

There is a high prevalence of atrial fibrillation (AF) in patients undergoing haemodialysis. Oral anticoagulant therapy with vitamin K antagonists (VKAs) is the only accepted treatment for the prevention of thromboembolism in haemodialysis patients with AF. However, in this population, the risk of bleeding is greatly increased. The aim of the study was to evaluate the ability of treatment quality indicators of VKA therapy to predict mortality and bleedings in a population of haemodialysis patients with AF. A total of 129 patients were included in this cohort study. Deaths and bleeding events were recorded during a follow-up of 4 years. In all patients, International Normalized Ratio (INR) values were assessed at least once a month. Time in therapeutic range (TTR) and INR variability, as measured by the standard deviation of INR, were updated at each INR measurement. A Cox model with time-dependent co-variates and sandwich variance was applied. During follow-up, 71 patients died and 55 bleeding episodes occurred in 31 patients. INR variability was the only indicator associated with both mortality (hazard ratio [HR]=1.67, 95% confidence interval [CI] 1.12; 2.49, p=0.012) and bleeding (HR=2.85, 95% CI: 1.71; 4.75, p=0.0001). HR of mortality was higher in patients with INR >3 (HR=2.06, 95% CI: 1.09; 3.88, p=0.0259) than in subjects in therapeutic range 2<INR≤3. TTR was inversely associated with the risk of recurrent haemorrhagic events (HR=0.88, 95% CI: 0.80; 0.95, p=0.0023), but not with a first episode of bleeding. Results were consistent after censoring patients at VKA withdrawal. Our study suggests that, in haemodialysis patients with AF taking VKAs, INR variability is the quality indicator that best predicts clinical outcomes. In this population, if more treatment quality indicators are considered together, it may become easier to identify patients at particularly high risk of bleeding and death.

Time in Therapeutic Range (TTR) and the Efficacy of Anticoagulant Therapy in Preventing Thromboembolism in Cardiac Patients Receiving Warfarin at Shifa Medical Complex: A Cross-Sectional Study

Background: Anticoagulant control is assessed by Time in Therapeutic Range (TTR). For a given patient, TTR is defined as the duration of time in which the patient’s International Normalized Ratio (INR) values were within a desired range. Aim: To assess TTR in patients receiving anticoagulant treatment and the efficacy of Anticoagulant therapy in preventing Thromboembolism in Cardiac Patients receiving Warfarin for atrial fibrillation and with high CHADS VASC score, valvular and non-valvular heart disease at a referral center for cardiovascular diseases at Gaza Shifa Medical Complex, Palestine. Materials and Method: Over 8 months, we enrolled eligible patients presenting to Shifa Medical Complex in Gaza for regular INR testing. Demographic data, medical history, and current medications were determined for all participants. TTR was assessed by both tradition and cross-sectional methods. Results: A total of 46 patients (mean age 57.15±12.6 years, 50% women) underwent 230 INR measurements. The mean TTR was calculated as 50.86±21.37%. Participants of this study were assessed for their risk of having stroke using CHADS VASC score and risk of bleeding using HAS BLED score. Risk of stroke was significantly higher for females (P= 0.031). Of the sample patients, 47.8% were in the good control category (TTR &gt;60%), and 52.2% were in the poor control category (TTR &lt;60%). The mean TTR of the studied patients (54.9%) was below the good control range.There were 12 participants had thromboembolism of patients with low traditional TTR. This was statistically significant, TTR with occurrence of thromboembolism, (P= 0.001). Conclusion: We found a mean TTR of 50.86% among study patients diagnosed with atrial fibrillation and high CHADS VASC score, valvular and non - valvular heart disease who were receiving warfarin therapy. None of the risk factor was significantly related to low TTR values among study participants. The study showed the low TTR was associated with increased risk of thromboembolism among participants in this study. Moreover, showed the superiority of tradition TTR over cross-sectional TTR in evaluating anticoagulant therapy.

Hypofibrinogenaemia and hypocalcaemia in adult trauma patients receiving pre-hospital packed red blood cell transfusions: Potential for supplementary pre-hospital therapeutic interventions.

To report the arrival ionised calcium (iCa) and fibrinogen concentrations in trauma patients treated with packed red blood cells by the road-based high-acuity response units of a metropolitan ambulance service. A retrospective review of trauma patients treated with packed red blood cells by high-acuity response units between January 2012 and December 2016. Patients were identified from databases at southeast Queensland adult trauma centres, Pathology Queensland Central Transfusion Laboratory, Gold Coast University Hospital blood bank and the Queensland Ambulance Service. Patient characteristics, results of laboratory tests within 30 min of ED arrival were analysed. A total of 164 cases were analysed. The median injury severity score was 33.5 (interquartile range 22-41), with blunt trauma the commonest mechanism of injury (n=128, 78.0%). Fifty-eight of the 117 patients (24.4%) with fibrinogen measured had a fibrinogen concentration ≤1.5g/L; 79 of the 123 patients (64.2%) with an international normalised ratio (INR) measurement had an INR >1.2; 97 of 148 patients (63.8%) with an iCa measured, had an iCa below the Pathology Queensland reference range of 1.15-1.32 mmol/L. Arrival fibrinogen concentration ≤1.5g/L and arrival iCa ≤1.00 were associated with in-hospital mortality with odds ratio11.90 (95% confidence interval 4.50-31.65) and odds ratio4.97 (95% confidence interval 1.42-17.47), respectively. Hypocalcaemia and hypofibrinogenaemia on ED arrival were common in this cohort. Future work should evaluate whether outcomes improve by correction of these deficits during the pre-hospital phase of trauma care.

In vitro analysis of n-acetylcysteine (NAC) interference with the international normalized ratio (INR)

Background Previous literature suggests a laboratory interference of n-acetylcysteine (NAC) with prothrombin time (PT) and the international normalized ratio (INR). Early publications focused on this interaction in the setting of an acetaminophen overdose and evaluated the INR of patients receiving intravenous NAC. However, there is limited literature describing the concentration-effect relationship of NAC to INR measurement in the absence of acetaminophen-induced hepatotoxicity at therapeutic NAC concentrations. The purpose of the study is to quantify the degree of interference of NAC on INR values at therapeutic concentrations correlating to each infusion of the regimen (ex. bag 1: 550 mcg/mL, bag 2: 200 mcg/mL, bag 3: 35 mcg/mL, double bag 3: 70 mcg/mL) and at supratherapeutic concentrations in vitro. Methods Blood samples were obtained from study volunteers. Each blood sample was transferred into vials containing 0.3 mL buffered sodium citrate 3.2% and spiked with various concentrations of NAC for final concentrations of 0, 35, 70, 200, 550, 1000, 2000, and 4000 mcg/mL. The samples were centrifuged and tested to determine PT and INR on two separate machines: Siemens CS-2500 and Stago SN1114559. We would require a sample size of 6 to achieve a power of 80% and a level of significance of 1.7% (two-sided). Differences between INRs at varying concentrations were determined by Friedman’s test. For multiple comparisons, post hoc analysis was performed using Wilcoxon signed-rank test with Bonferroni adjustment. Analyses were performed with SAS version 9.4 (SAS Institute, Cary, NC). Results Participants included 11 healthy subjects: 8 males, 3 females, median age 30 years (range 25 − 58). Median and interquartile ranges (IQR) INR for the baseline samples were 1.09 (IQR 1.05, 1.16) for Siemens and 1.03 (IQR 0.99, 1.11) for Stago analyzers. There was a significant difference in INR between the therapeutic concentrations (baseline, 35, 70,200, or 550 µg/mL) (Siemens p = .0008, Stago p < .0001). The 550 µg/mL concentration with the Siemens analyzer was the only one compared separately and found to be significantly greater than the baseline (1.07 vs 1.22, p = .02). For the Stago analyzer the 200 µg/mL and 500 µg/mL were compared and found to be significantly different from baseline (1.00 vs 1.07 and 1.19, adjusted p = .02 and p = .03, respectively). The largest INR increase seen was in one subject from a baseline of 1.07–1.32 with the 550 µg/mL concentration. Increases in concentrations to supratherapeutic levels resulted in a statistically significant non-linear increase in INR for all concentrations (Siemens p < .0001, Stago p < .0001). All of these concentrations were found to be significantly different from baseline (all adjusted p < .05). Conclusion Although it was found that at therapeutic concentrations the in vitro presence of NAC affects INR measurements on two different machines, the change is of little clinical relevance. Supratherapeutic concentrations of NAC affect INR significantly, but the clinical utility of those results is limited by the rarity of those concentrations being measured.

Risk of stroke and other thromboembolic complications after interruption of DOAC therapy compared with warfarin therapy in patients with atrial fibrillation: a retrospective cohort analysis

Direct oral anticoagulants (DOACs) have become the treatment of choice in thromboembolism prophylaxis for non-valvular atrial fibrillation, surpassing warfarin. While interruption of DOAC therapy for various reasons is a common...

A retrospective analysis of discordances between international normalized ratio (INR) self-testing and INR laboratory testing in a pediatric patient population.

The lack of quality control procedures for home point-of-care (POC) international normalized ratio (INR) devices is a concern. Concomitant laboratory and POC INR testing may be proposed to overcome the lack of quality control. However, a difference between the POC INR and the laboratory INR is not necessarily due to failure of the POC device. This study aimed to identify variables associated with a significant deviation between the POC INR and the laboratory INR. Children included in this retrospective cohort study performed at least one concomitant laboratory and POC INRs. Clinical and laboratory variables were assessed for an association with significant deviation within pairs of INR. A significant deviation was noted for 30 (15.3%) of the 196 pairs of INR measurements from 124 children. Relative to patients without deviations, patients with deviations were younger (odds ratio =0.91; P=.020), less experienced in the use of POC INR devices (odds ratio =0.89; P=.098), and more likely to have received an INR result from a laboratory using animal thromboplastin (odds ratio =2.81 vs. 0.37 for laboratories using human thromboplastin; P=.016). In a multivariate analysis, younger age and the laboratory's use of animal thromboplastin were associated with significant deviations. Although most children had coherent pairs of INR values, the occurrence of deviations raises the question of the origin of the thromboplastin used in the laboratory and emphasizes the need to provide specific quality control procedures for POC INR devices.

Reliability of CoaguChek Pro II Point of Care System in Outpatient Setting in Farwaniya Hospital, Kuwait

Point of care testing (POCT) coagulometers are widely used for international normalized ratio (INR) monitoring for patients on vitamin K antagonists (VKA) therapy. In our study, we investigated the accuracy and reliability of CoaguChek pro II (Roche Diagnostics) as an alternative for standard laboratory testing (SLT) by ACL TOP 500 top system in outpatient department setting. Methods: We enrolled a total of 174 INR results in our study which were measured by CoaguChek ProII and ACL TOP 500 top. The three arms of the study were: INR <3.5, 3.5-4.4, and ≥4.5. The results were compared using Passing Bablok regression analysis and Bland-Altman plot. The agreement between the two methods was further evaluated to demonstrate the impact on dosing decision. Furthermore, the degree of patient satisfaction with POCT in our INR clinic was assessed by participating in a survey. Results: The overall correlation of INR measurements between POCT and SLT in our study was strong (r = 0.95), however, the correlation between the two methods in the 3.5-4.4 arm was moderate (r = 0.502). The overall agreement between the two methods in all three arms of the study in terms of dosing decision was good (Kappa = 0.862), with only 12.6% of INR measurements showing a difference in dosing decision. Ninety-Seven percent of all INR values measured by CoaguChek Pro II within therapeutic range (INR<3.5) were within 0.5 INR units when compared to ACL TOP 500 Top. Furthermore, we concluded that more than 90% of the patients in our center were satisfied with the POC service. Conclusion: We concluded that POCT is a good alternative to SLT in INR values falling in therapeutic and supra-therapeutic ranges; however, additional comparative studies investigating the accuracy and reliability between the two methods for INR results between 3.5-4.4 will add to the current body of knowledge. Furthermore, the majority of patients were satisfied with the service provided in the POC INR clinic.

A New Method for the Measurement of International Normalized Ratio in Hemodialysis Patients with Heparin-Locked Tunneled Dialysis Catheters.

Background To measure International Normalized Ratio (INR) in hemodialysis patients with tunneled dialysis catheters (TDCs), blood sampling is frequently obtained via the catheter at the start of the session. INR measurements via finger-prick point of care testing (POCT) and via blood sampling taken from the dialysis circuit are evaluated as alternatives. Methods In 14 hemodialysis patients with TDCs, treated with vitamin K antagonists (VKA), INR measurements via POCT were compared with plasma INR samples taken via the catheter at the start of dialysis and via the dialysis circuit after 30 and 60 minutes during 3 nonconsecutive dialysis sessions. Results Blood samples taken at the start of dialysis at the catheter site were frequently contaminated with heparin originating from the locking solution (unfractionated heparin concentration (UFH) >1.0 IU/ml in 13.2%). POCT INR at the start of dialysis was not different from plasma INR after 30 and 60 minutes (Wilcoxon test p=0.113, n = 37, and p=0.631, n = 36, respectively). Moreover, there was no difference between POCT INR at the start of dialysis and POCT INR after 30 and 60 minutes (Wilcoxon test p=0.797 and p = 0.801, respectively; n = 36). Passing and Bablok regression equation was used, y = 0.460 + 0.733x; n = 105. Treatment decisions based on these 2 methods showed a very good overall agreement (kappa = 0.810; 95% CI: 0.732–0.889; n = 105). Conclusions Measuring plasma INR via the TDC at the start of dialysis should be abandoned. Measuring POCT INR via a finger prick at the start or even after 30 to 60 minutes is an alternative. The most elegant alternative is to take plasma INR samples via the dialysis circuit 30 minutes or later after the start of the dialysis.

Evaluating the Use of Warfarin Using the HAS-BLED Score and INR on Atrial Fibrillation Patients at Harapan Kita National Heart Center

Patients with atrial fibrillation are associated with a 4-5-fold risk of having a stroke. The most effective treatment for atrial fibrillation is to prevent the formation of blood clots by administering anticoagulant drugs. Warfarin is an anticoagulant drug that has a narrow therapeutic index with side effects of the risk of bleeding; hence it needs supervision in its use. In this study, the HAS-BLED score was used to measure major bleeding risk and as a value representing each risk factor for bleeding. The bleeding risk can be prevented by maintaining a warfarin response in the therapeutic range with an INR (International Normalized Ratio) measurement 2-3. This study was an observational study conducted with retrospective data collection through medical records of patients with a primary diagnosis of atrial fibrillation who received oral warfarin anticoagulant therapy at Harapan Kita National Heart Center in the period of January-December 2017. Using a sample of 40 patients who met the inclusion criteria. According to the data, found that atrial fibrillation patients who received oral warfarin therapy 55% were male patients, while 45% were female patients. Patients with atrial fibrillation who got the most oral warfarin therapy were patients who were over 40 years old with 90% of the total sample, with the highest group in patients aged 50-54 years with 22.5%. The HAS-BLED values arranged from 0-9, the percentage of patients who had HAS-BLED values of 0, 1, 2 respectively at 7.5%, 42.5%, 30%. The HAS-BLED score ≥ 3 showed patients classified as at high risk of bleeding by 20%. The most risk factors based on HAS-BLED score from all study samples were 18 patients with abnormal kidney or 45%. The average INR score in patients at high risk of bleeding showed that 37.5% had an average INR score in the target ratio score of INR 2-3.

Heartbeat: increased use of NOACs in patients with atrial fibrillation reduces health care system costs by reducing stroke incidence

A major goal in management of adults with atrial fibrillation (AF) is prevention of stroke. In an editorial, our stroke neurology colleagues1 point out that about 1/3 of patients with...