Abstract 77: Balancing Risks and Benefits of Anticoagulation Therapy in Atrial Fibrillation in Community Practice: Results from the ORBIT-AF Registry

Author(s):  
Michael W Cullen ◽  
Sunghee Kim ◽  
Jonathan P Piccini ◽  
Alan S Go ◽  
Gregg C Fonarow ◽  
...  

Background Oral anticoagulation (OAC) can reduce stroke risk at the cost of increased bleeding risk in those with atrial fibrillation (AF). Observational data have shown that higher-risk patients with AF most likely to benefit from OAC are less likely to receive OAC at hospital discharge. Methods We used data from ORBIT-AF Registry, a cohort of 9,589 AF patients enrolled among 173 participating outpatient practices. OAC was defined as warfarin or dabigatran use at study enrollment. Stroke and bleeding risk were calculated using the CHADS2 and ATRIA scores, respectively. Results The study population had a mean age of 73.5 years; 57.8% were men. Overall, 76.4% of patients received OAC. Use of OAC rose with increasing CHADS2 stroke risk, from 67% for CHADS2 <1 to 80% for CHADS2 ≥2 (p<0.0001). OAC use fell slightly with increasing ATRIA bleeding risk, from 77% for ATRIA score ≤3 to 74% with ≥5 (p=0.002 for trend). Among patients with low bleeding risk, rates of OAC increased commensurate with stroke risk (p<0.0001 for interaction; see figure). Higher bleeding risk tended to decrease rates of OAC among patients with a CHADS2 score ≥2 (p=0.13 for interaction). Conclusions In community-based outpatients with AF, use of OAC rose with increasing thromboembolic risk and declined with higher bleeding risk. These findings suggest that the risk-treatment paradox may be less that previously reported. Provision of OAC in community practice appears to appropriately consider patients' stroke and bleeding risks. Further research is required to understand how quality improvement initiatives can further improve stroke prevention.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Fengpeng Jia ◽  
Minghuan Fu ◽  
Zhiyu Ling ◽  
Suxin Luo ◽  
Jun Gu ◽  
...  

Background: The study was to evaluate the value of CHADS2 and CHADS2VASC scores on predicting left atrial (LA) thrombus in the patients with atrial fibrillation (AF). Methods and Results: All the non-valvular AF patients undergoing AF ablation from June 2010 to June 2012 were included and divided into two groups: patients without anticoagulation and with Coumadin anticoagulation for at least 4 weeks. The relationship between CHADS2 and CHADS2VASC scores and LA thrombus as identified on transesophageal echocardiography (TEE) was analyzed prior to ablation. A total of 397 patients underwent pre-ablation TEE: 212 patients without anticoagulation, and 185 with anticoagulation. There were no differences in the CHADS2 and CHADS2VASC scores in the two groups. LA thrombus was present in 15.6% and 5.9% for the patients without anticoagulation and for those with anticoagulation, respectively (p = 0.002). There was a strong association between CHADS2 and LA thrombus, and between CHADS2VASC and LA thrombus in the two groups. No thrombus was identified in patients with CHADS2VASC score of 0 in both groups. However, thrombus was detected in 3.5% of patients with CHADS2 score of 0 in the group without anticoagulation, while no thrombus was present in the ones with anticoagulation. CHADS2VASC score of ≥1 (r=2.03, p = 0.04) was the only factor independently associated with LA thrombus in patients without anticoagulation, while both CHADS2VASC score of ≥2 (r=2.61, p=0.02) and CHADS2 score of ≥2 (r=2.73, p=0.01) were independently associated with LA thrombus. Further analyses showed that CHADS2VASC score was a better predictor for LA thrombus than CHADS2 score in patients without anticoagulation. However, there was no difference between the two scoring systems in predicting LA thrombus in patients with anticoagulation. Conclusions: LA thrombus was associated with CHADS2VASC and CHADS2 scores in non-valvular AF patients without anticoagulation. CHADS2VASC score was a better predictor than CHADS2 score for LA thrombus in patients without anticoagulation. The data suggested that it might be unnecessary to undergo a TEE evaluation for LA thrombus in low risk patients identified by CHADS2VASC score regardless anticoagulation therapy prior to cardioversion or ablation.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sara Aspberg ◽  
Yuchiao Chang ◽  
Daniel Singer

Introduction: Atrial fibrillation (AF) is a major risk factor for acute ischemic stroke (AIS). Anticoagulation therapy (OAC) effectively prevents AIS, but increases bleeding risk. There is a need for better AIS risk prediction to optimize the anticoagulation decision in AF. The ATRIA stroke risk score (ATRIA) (table) was superior to CHADS2 and CHA2DS2-VASc in two large California community AF cohorts. We now report the performance of the 3 scores in a very large Swedish AF cohort. Methods: The cohort consisted of all Swedish patients hospitalized with a diagnosis of AF from July 1, 2005 to December 31, 2008. Predictor variables and the outcome, AIS, were obtained from inpatient ICD-10 codes. Warfarin use was determined from National Pharmacy Database. Risk scores were assessed via c-index (C) and net reclassification index (NRI). Results: The cohort included 158,370 AF patients off warfarin who contributed 340,332 person-years of follow-up, and 11,823 incident AIS, for an overall AIS rate of 3.47%/yr, higher than the 2%/yr seen in the California cohorts. Using the entire point score, ATRIA had a good C of 0.712 (0.708-0.716), significantly better than CHADS2, 0.694 (0.689-0.698), or CHA2DS2-VASc, 0.697 (0.693-0.702). Using published cut-points for Low/Moderate/High AIS risk, C deteriorated for all scores but ATRIA and CHADS2 were superior to CHA2DS2-VASc. NRI favored ATRIA; 0.16 (0.15-0.18) versus CHADS2; 0.22 (0.21-0.24) versus CHA2DS2-VASc. However, NRI decreased to near-zero when cut-points were altered to better fit the cohort’s stroke rates. Conclusion: Findings in this large Swedish AF cohort validate those in the California AF cohorts, with the ATRIA score predicting stroke risk better than CHADS2 or CHA2DS2-VASc. However, relative performance of the categorical scores varied by population stroke risk. Knowledge about this population risk may be needed to optimize cut-points on the multipoint scores to achieve better net clinical benefit from OAC.


2009 ◽  
Vol 102 (10) ◽  
pp. 754-758 ◽  
Author(s):  
Gerhard Hindricks ◽  
Hans Kottkamp ◽  
Philipp Sommer ◽  
Thomas Gaspar ◽  
Kerstin Bode ◽  
...  

SummaryCatheter ablation provides curative treatment for atrial fibrillation (AF). Data on anticoagulation after the procedure are sparse. We investigated real-life antithrombotic treatment after AF ablation and examined its adherence to current recommendations. Eight hundred forty-four patients (age 58 ±10 years) underwent AF ablation. Most patients had a CHADS2 score of 0 (46%) or 1 (45%). Seven-day Holter was performed at three, six and 12 months after ablation. Decision on anticoagulation treatment was made by general practitioners and referring cardiologists in consultation with the patients. At discharge, anticoagulants were prescribed for the vast majority (94–96%) of patients. This percentage remained high at three and six months (80–90%) without differences between stroke risk groups. At 12 months, the use of anticoagulants was mainly influenced by the detection of recurrence; usage exceeded 90% in all stroke risk groups in patients with recurrences. In patients without recurrences, differences between risk groups were significant but small, ranging from 42% (CHADS2=0) to 62% (CHADS2≥2) (p=0.033). In multivariate analysis, the only factor independently associated with oral anticoagulation at 12 months was the detection of recurrences (odds ratio=16.2, p<0.001), whereas the effect of the CHADS2 score was not significant (p=0.080).The effect of all other examined factors was also not significant. Contrary to current recommendations, anticoagulation after AF ablation is hardly guided by the stroke risk profile and remains high even in low-risk patients. The most important factor influencing the use of anticoagulants is the detection of recurrences during follow-up. This results in possible overtreatment of low-risk patients.


Author(s):  
Julie Lauffenburger

Background: Atrial fibrillation (AF) often benefits from the use of anticoagulants for prevention of stroke or systemic embolism. While novel oral anticoagulants have emerged as possible alternatives to warfarin, it is unknown how treatment selection is determined in practice with clinical guidelines still evolving. This study examined whether and to what extent anticoagulant selection has been driven by clinical predictions of stroke risk (treatment benefit) and bleeding risk (treatment harm) in real-world practice in the US. Methods: A nationwide database of commercial and Medicare Part D supplement claims from 2009-2011 was used to extract a cohort of non-valvular AF patients who were newly-initiating therapy after dabigatran availability in Oct 2010. Patients were excluded if they had claims associated with a reversible AF condition. Risk scores of ischemic stroke (CHADS2 and CHA2DS2-VASc) and bleeding (ATRIA) were used to examine associations with either warfarin or dabigatran use, calculated via claims in the outpatient pharmaceutical, inpatient medical, outpatient, and provider claims files. Baseline demographic and clinical characteristics were also measured as covariates, including concomitant diseases and medications. Multivariable log-binomial regression models assessed the association between each risk score and anticoagulant use, adjusting for the measured covariates. C-statistics were also used to examine the variation in treatment selection explained by inclusion of the risk scores. Results: In total, 37,401 patients were identified with 31% initiating dabigatran. New users of dabigatran were more likely to be younger, male, and have comorbidities. Patients at intermediate stroke risk (CHADS2 or CHA2DS2-VASc =1) were equally likely to receive warfarin and dabigatran (RR, 95% CI: 0.98, 0.93-1.02), while selection for warfarin was significantly associated with high ischemic stroke risk (CHADS2 or CHA2DS2-VASc ≥2) (RR, 95% CI: 0.87, 0.83-0.92). New users of dabigatran were significantly less likely to have high bleeding risk (ATRIA≥5) versus warfarin (RR, 95%: 0.70, 0.66-0.74). The c-statistic of the base model, which included the other measured covariates, was only marginally increased with the addition of any of the risk scores. Conclusions: Despite controlling for other patient characteristics, bleeding risk was strongly associated with the selection of a specific anticoagulant. However, the extent of selection explained by predictions of treatment harm was minimal. Providers appear to base anticoagulant selection on factors other than predictions of treatment benefit, which has implications for studying the anticoagulants’ comparative effectiveness.


Author(s):  
Emily C O’Brien ◽  
DaJuanicia Holmes ◽  
Larry A Allen ◽  
Daniel E Singer ◽  
Gregg C Fonarow ◽  
...  

Background. Warfarin reduces the risk of thromboembolic events associated with atrial fibrillation (AF), but therapeutic persistence is suboptimal. Few studies have investigated the reasons for warfarin discontinuation in community practice. Methods. We used data from ORBIT-AF, the nation’s largest AF database, to examine patterns of warfarin discontinuation over a one-year period. Patients transitioned to non-warfarin oral anticoagulation therapy were excluded. We compared patient and provider characteristics between individuals who discontinued warfarin and those who persisted. Results. From June 2010 to August 2011, 10,126 AF patients 18 years or older were enrolled at 176 ORBIT-AF practices. Of these, 6,559 (64.8%) were taking warfarin at baseline and have follow-up data; 514 (7.8%) of these switched to dabigatran and were excluded from the analysis. Additionally, two patients without follow-up warfarin data were excluded from the analysis. Over one year, 587 patients (9.7%) discontinued warfarin therapy. Compared to persistent users, patients who discontinued warfarin were younger, less likely to be white, had lower stroke risk (CHADS 2 <2), were more likely to follow a rhythm control strategy, and were less likely to be managed in an anticoagulation clinic (Table 1). The most commonly reported reasons for warfarin discontinuation were physician preference (31.0%), other (18.7%), patient refusal/preference (13.6%), bleeding event (13.3%), frequent falls/frailty (7.3%), high bleeding risk (6.6%), and patient inability to adhere to/monitor therapy (2.9%). Conclusions. Discontinuation of warfarin is common among patients with atrial fibrillation. Patient and physician preference are major contributors to persistence on warfarin therapy.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256338
Author(s):  
Samuel W. Reinhardt ◽  
Nihar R. Desai ◽  
Yuanyuan Tang ◽  
Philip G. Jones ◽  
Jeremy Ader ◽  
...  

Background The RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial demonstrated that higher-risk patients with atrial fibrillation had lower rates of stroke or systemic embolism and a similar rate of major bleeding, on average, when treated with dabigatran 150mg compared to warfarin. Since population-level averages may not apply to individual patients, estimating the heterogeneity of treatment effect can improve application of RE-LY in clinical practice. Methods and results For 18040 patients randomized in RE-LY, we used patient-level data to develop multivariable models to predict the risk for stroke or systemic embolism and for major bleeding including all three treatment groups (dabigatran 110mg, dabigatran 150mg, and warfarin) over a median follow up of 2.0 years. The mean predicted absolute risk reduction (ARR) for stroke/systemic embolism with dabigatran 150mg compared to warfarin was 1.32% (range 11.6% lower to 3.30% higher risk). The mean predicted ARR for bleeding was 0.41% (range 8.93% lower to 63.4% higher risk). Patients with increased stroke/systemic embolism risk included those with prior stroke/TIA (OR 2.01), diabetics on warfarin (OR 2.00), and older patients on dabigatran 150mg (OR 1.68 for every 10-year increase). Major bleeding risk was higher in patients on aspirin (OR 1.25), with a history of diabetes (OR 1.34) or prior stroke/TIA (OR 1.22), those with heart failure on dabigatran 110mg (OR 1.52), older patients on either dabigatran 110mg or 150mg (OR 1.57 and 1.93, respectively, for each 10-year increase), and heavier patients on dabigatran 110mg or 150mg; patients in a region outside the United States and Canada and with better renal function had lower bleeding risk. Conclusions There is substantial heterogeneity in the benefits and risks of dabigatran relative to warfarin among patients with atrial fibrillation. Using individualized estimates may enable shared decision making and facilitate more appropriate use of dabigatran; as such, it should be prospectively tested. Clinical trial registration www.clinicaltrials.gov number, NCT00262600.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Anat Bel-Ange ◽  
Shani Zilberman Itskovich ◽  
Liana Avivi ◽  
Kobi Stav ◽  
Shai Efrati ◽  
...  

Abstract Background We tested whether CHA2DS2-VASc and/or HAS-BLED scores better predict ischemic stroke and major bleeding, respectively, than their individual components in maintenance hemodialysis (MHD) patients with atrial fibrillation (AF). Methods A retrospective cohort study of a clinical database containing the medical records of 268 MHD patients with non-valvular AF (167 women, mean age 73.4 ± 10.2 years). During the median follow-up of 21.0 (interquartile range, 5.0–44.0) months, 46 (17.2%) ischemic strokes and 24 (9.0%) major bleeding events were reported. Results Although CHA2DS2-VASc predicted ischemic stroke risk in the study population (adjusted HR 1.74 with 95% CI 1.23–2.46 for each unit of increase in CHA2DS2-VASc score, and HR of 5.57 with 95% CI 1.88–16.49 for CHA2DS2-VASc score ≥ 6), prior ischemic strokes/transient ischemic attacks (TIAs) were non-inferior in both univariate and multivariate analyses (adjusted HR 8.65 with 95% CI 2.82–26.49). The ROC AUC was larger for the prior ischemic stroke/TIA than for CHA2DS2-VASc. Furthermore, the CHA2DS2-VASc score did not predict future ischemic stroke risks in study participants who did not previously experience ischemic strokes/TIAs (adjusted HR 1.41, 95% CI: 0.84–2.36). The HAS-BLED score and its components did not have predictive abilities in discriminating bleeding risk in the study population. Conclusions Previous ischemic strokes are non-inferior for predicting of future ischemic strokes than the complete CHA2DS2-VASc score in MHD patients. CHA2DS2VASc scores are less predictive in MHD patients without histories of CVA/TIA. HAS-BLED scores do not predict major bleeding in MHD patients. These findings should redesign approaches to ischemic stroke risk stratification in MHD patients if future large-scale epidemiological studies confirm them.


2021 ◽  
Vol 12 ◽  
pp. 215013272110002
Author(s):  
William Uribe-Arango ◽  
Juan Manuel Reyes Sánchez ◽  
Natalia Castaño Gamboa

Objectives To assess budget impact of the implementation of an anticoagulation clinic (AC) compared to usual care (UC), in patients with non-valvular atrial fibrillation (NVAF). Method A decision tree was designed to analyze the cost and events rates over a 1-year horizon. The patients were distributed according to treatment, 30% Direct Oral Anticoagulant (DOAC) regimens and the rest to warfarin. The thromboembolism and bleeding were derived from observational studies which demonstrated that ACs had important impact in reducing the frequency of these events compared with UC, due to higher adherence with DOACs and proportion of time in therapeutic range (TTR) with warfarin. Costs were derived from the transactional platform of Colombian government, healthcare authority reimbursement and published studies. The values were expressed in American dollars (USD). The exchanged rate used was COP $3.693 per dollar. Results During 1 year of follow-up, in a cohort of 228 patients there were estimated 48 bleedings, 6 thromboembolisms in AC group versus 84 bleedings, and 12 thromboembolisms events in patients receiving UC. Total costs related to AC were $126 522 compared with $141 514 in UC. The AC had an important reduction in the cost of clinical events versus UC ($52 085 vs $110 749) despite a higher cost of care facilities ($74 436 vs $30 765). A sensibility analysis suggested that in the 83% of estimations, the AC produced savings varied between $27 078 and $135 391. Conclusions This study demonstrated that AC compared with UC, produced an important savings in the oral anticoagulation therapy for patients with NVAF.


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