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Introduction: Warfarin and non-vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran are effective for the prevention of stroke and systemic embolism in patients with atrial fibrillation (AF). However, few analyses have compared persistence rates of warfarin vs. dabigatran-treated patients. Methods: The ORBIT-AF registry enrolled patients with AF from 173 clinical practices across the US. One-year persistence of warfarin vs. dabigatran was defined as treatment at baseline visit and at 1-year follow-up. Multivariable logistic regression analysis was used to identify characteristics associated with warfarin or NOAC persistent use. Results: At baseline, 6.4% (N=459/7,150) were treated with dabigatran and 93.6% (N=6,691/7,150) with warfarin. Patients treated with warfarin at baseline were older (74 vs. 71, p<.0001), had more NYHA class III/IV heart failure (7 vs. 5, p=.0007), lower creatinine clearance (77 vs. 88, p<.0001), higher CHA2DS2-VASc risk scores, and more prior CVA/TIA events (16 vs. 11, p=.003). Patients treated with dabigatran had more severe symptoms (EHRA class III: 20 vs. 14, p<.0001), higher rates of treatment with a rhythm control strategy (42.7 vs. 28.2, p<.0001), more attempts at cardioversion (38.3 vs. 32.1, p<.006), and catheter ablation of AF (9.8 vs. 5.2, p<.0001). At 12 months, adjusted persistence rates for warfarin were higher than dabigatran [82% (80-84) vs. 67% (61-73) p<.0001]. Factors independently associated with one year persistence were: African American race (OR 1.53, 95% C.I. 1.07-2.19, p=0.02), Hispanic race (OR 1.66, 95% C.I. 1.06-2.60), paroxysmal AF (vs. new onset) (OR 1.68, 95% C.I. 1.21-2.33, p=.002), LVH (OR 1.40, 95% C.I. 1.08-1.81, p=.01), persistent AF (vs. new onset) (OR 1.91, 95% C.I. 1.35-2.69, p=.0002), and CHA2DS2-VASc risk scores ≥ 2 (OR 1.94, 95% C.I. 1.18-3.19, p=.009). Conclusion: Persistence rates for warfarin were higher at one year than those on dabigatran. In addition, factors associated with persistence of warfarin include: African American and Hispanic race, type of AF including permanent and persistent, LVH, and CHA2DS2-VASc risk scores ≥ 2.

Background: Little is known about whether insurance status affects the presentation and treatment of patients with atrial fibrillation (AF). Methods: We used data from the ORBIT-AF Registry (2010 - 2011), a national, large outpatient registry, to evaluate clinical characteristics and oral anticoagulation (OAC) use. We examined differences in comorbidities and receipt of OAC among patients enrolled in the Medicaid program at baseline compared with those not enrolled in Medicaid. After restricting to patients who were taking OAC, we compared receipt of novel oral anticoagulants (dabigatran or rivaroxaban) versus warfarin by Medicaid status during 2 years of followup. We used logistic regression models adjusting for demographic and clinical covariates to evaluate baseline OAC receipt by Medicaid status. Results: Of 10,133 patients, N=470 (4.6%) were classified as having Medicaid insurance. Compared with those with other insurance, Medicaid patients were younger (70.0 years; IQR=61.0 - 79.0 vs. 75.0 years; IQR=67.0 - 82.0), more likely to be female (53.0% vs. 41.8%), and less likely to be white (58.7% vs. 90.7%; all p<0.001). Medicaid patients had higher rates of smoking, prior stroke/TIA, diabetes, hypertension, and HF. Medicaid patients were less likely to be taking OAC at baseline, a difference that was particularly pronounced for high stroke risk patients (CHADS2>=2, p<0.001; Table). Among those on anticoagulation, Medicaid patients were less likely to receive NOAC over 2 years of followup. In adjusted analyses, Medicaid patients were less likely to receive OAC at baseline, but this difference was not statistically significant (HR = 0.82; 95% CI = 0.61, 1.09). Among untreated patients with CHADS2>=2, Medicaid patients were more likely than patients with other insurance to have “unable to adhere/monitor” listed as a contraindication to OAC (p<0.001). Conclusions: In a contemporary, community-based AF cohort, Medicaid patients had a greater comorbidity burden and higher stroke risk, yet were less likely to receive OAC compared with those with other forms of insurance.

Background: Novel therapies for stroke prevention in atrial fibrillation (AF) are emerging. However, data on use and outcomes of these agents in the community are limited, particularly in patients newly diagnosed with AF or recently transitioned to a novel anticoagulant. Methods: Phase II of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF II) is a multicenter, national, AF registry. We are enrolling 15,000 patients with new-onset AF, or those with known AF recently-transitioned to a novel anticoagulant. The primary objective is to evaluate the safety of novel anticoagulants, with specific focus on use, transitions, and management around invasive procedures and bleeding events. An adaptive design is used to ensure diversity of enrollment across geographic, provider, and treatment groups. The primary outcomes are major bleeding and thromboembolic events. Results: Of 1,011 patients in ORBIT-AF II, the median age was 73, 44% were female, 23% had a history of heart failure, 34% had a prior MI, and 11% had a prior stroke/TIA. The mean CHADS2 score was 2. Overall, 76% had AF new-onset, and a range of anticoagulant strategies was used in these patients (Figure). Among the 24% with known AF transitioned to a novel agent, 66% received rivaroxaban, versus 8.1% dabigatran, and 26% apixaban. Compared with patients having new-onset AF, those with known AF recently-transitioned to a novel anticoagulant were slightly older (median age 74 vs. 72), had higher CHADS2 scores (>2 in 70% vs. 62%), but less severe kidney disease (0 vs. 1.7%). Conclusions: Patients with new-onset AF are frequently treated with novel anticoagulants and these patients have lower risk scores than those with known AF transitioned to a novel drug. These data will provide insights into clinical management and patient centered outcomes among those treated with novel anticoagulants in real world practice settings.

Objective: Time in the therapeutic range (TTR) of INR 2.0-3.0 is an important measurement of warfarin anticoagulation quality. There are few reports on TTR in United States (US) clinical practice. Methods: Using the US ORBIT AF registry, we analyzed TTR for patients on warfarin with at least 5 recorded INR measurements. The Rosendaal method of linear interpolation was used between each pair of measured INR values. Patients were stratified into quartiles based on TTR. Results: We studied 5,451 patients treated at 169 US sites with 48% of patients being followed at an anticoagulation clinic. Patients had a median age of 76 years [interquartile range (IQR) 68-82 years] and median follow-up was 18.9 months [IQR 12.7-23.3 months], and patients were 42% women. The median number of INR draws was 21 [IQR 12-30]. Patients had an overall median TTR of 68% [IQR 52-80%]. The median TTR by quartile was 40%, 60%, 73%, and 87%. Patients were more likely to be subtherapeutic (median time of 17%) than supratherapeutic (median time of 10%). Patients age 61-80 years and those with a college education had the highest TTRs. Patients with their INR followed at an anticoagulation clinic were more likely to be in the highest TTR quartile than in the lowest (27% vs 23%, p=0.0002). Patients with worsening renal function and higher risk for bleeding (ATRIA) or stroke (CHADS2 score) had lower TTR (p<0.0001 for all) (Figure). Conclusions: In US clinical practices, warfarin patients have therapeutic INR levels about 2/3 of the time. Those at highest risk for stroke and bleeding paradoxically were the least likely to be in the therapeutic range.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia in current clinical practice. Yet, contemporary community data on adverse outcomes, such as ischemic stroke (IS) and heart failure (HF), are scarce. Methods: We assembled a community-based cohort of incident AF among Olmsted County, MN residents ≥18 years of age from 2000-2010. IS, transient ischemic attack (TIA), and incident HF occurring through 12/31/2012 were identified using diagnosis codes and were manually validated. Cox proportional hazards regression was used to determine age- and sex-adjusted predictors of IS/TIA and HF, as well as the association of year of AF diagnosis with these outcomes after adjustment for demographics and comorbidities. Results: Among 3315 incident AF (mean age 72.6 years, 52% male), 346 (10%) developed a subsequent IS (n=230) or TIA (n=116) over a mean follow-up of 4.2 years. In the 2807 AF patients without prior HF, 782 (28%) developed HF over a mean of 3.9 years. Differences in the predictors of subsequent IS/TIA and HF were observed (Figure). Increasing age, female sex, and prior IS/TIA were associated with an increased risk of IS/TIA, whereas increasing age, obesity, smoking, prior myocardial infarction, diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, prior IS/TIA, and renal disease predicted the development of HF after AF. The risk of subsequent IS/TIA or HF did not differ by year of AF diagnosis. Compared to those diagnosed with AF in 2000-2003, the adjusted hazard ratios (HR) (95% CI) for ischemic IS/TIA were 0.84 (0.65-1.08) and 1.02 (0.76-1.36) for those diagnosed with AF in 2004-2007 and 2008-2010, respectively (P time trend =0.58); similar results were observed for IS alone. The corresponding HRs for HF were 0.99 (0.83-1.16) and 0.93 (0.76-1.13) for those diagnosed with AF in 2004-2007 and 2008-2010 compared to 2000-2003 (P time trend =0.43). Conclusions: In the community, adverse outcomes are frequent after AF, and HF occurs more frequently than IS/TIA. Risk factors differed for IS/TIA and HF, suggesting that pathways to the occurrence of these outcomes, as well as prevention strategies, may differ. Finally, the occurrence of these outcomes did not decline over the last decade, highlighting the importance of continued rigorous surveillance of adverse outcomes in AF.

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.

Background: The package insert for apixaban recommends against its use for stroke prevention in patients with atrial fibrillation (AF) with prosthetic heart valves. There are no published data on the use of apixaban in patients with AF with bioprosthetic valves. This analysis provides preliminary exploratory data on the safety and efficacy of apixaban in these patients. Methods: The ARISTOTLE trial randomized patients with AF to apixaban versus warfarin, and patients with a history of bioprosthetic valve replacement were eligible for inclusion in the trial. In this secondary analysis, baseline characteristics of patients with bioprosthetic valves were compared between apixaban and warfarin patients using Wilcoxon tests for continuous variables and chi-square tests for categorical variables. Unadjusted endpoints were compared between randomized treatments using a Cox regression model. With data collection on these valve patients ongoing, this interim report represents 82 of 260 patients with a history of valve surgery from ARISTOTLE. Results: Among 82 patients with bioprosthetic valves, 41 patients each were in the apixaban and warfarin arms. The patients had a median age of 78 years (vs. 70 years in overall trial), 18% had prior stroke (vs. 19% in overall trial), and 41% had concomitant aspirin use (vs. 31% in overall trial). Other than a higher rate of hypertension in the warfarin arm (98% vs. 81%, p=0.03), there were no statistically significant differences in baseline characteristics between the two groups. There were few events in patients with bioprosthetic valves. There were 2 stroke events, and there were no statistically significant differences between the apixaban and warfarin groups for major bleeding, stroke/systemic embolism, all-cause death, or cardiovascular death (Table). Conclusions: Among the small number of patients in ARISTOTLE with bioprosthetic valves, there were few events with similar event rates in both the apixaban and warfarin groups.

Background: Oral anticoagulation (OAC) is effective at preventing stroke in patients with atrial fibrillation (AF), yet warfarin is often poorly tolerated. Non-vitamin K oral anticoagulants (NOACs) are as or more effective as warfarin, yet their tolerance and persistence in clinical practice is not known. Methods: We assessed patterns of persistent OAC use among 2,345 AF patients starting on therapy in the ORBIT-AF II registry (71% starting on a NOAC, and 29% on warfarin). Results: By 6 months, 364 (22%) patients started on a NOAC had discontinued or changed initial therapy versus 143 (21%) started on warfarin initially (p=0.5). Among warfarin users, patients who switched or discontinued therapy were of similar age (median ages 72 and 74 vs. 74 for stable users, p=0.7) and CHA2DS2-VASc scores (mean 98 and 3.66 vs. 3.84, p=0.4). Among NOAC users, those who discontinued treatment were younger (median age 68 vs. 73 for those who switched and 72 for stable users; p=0.0004), and lower CHA2DS2-VASc scores (3.02 vs. 3.58 and 3.47, respectively; p=0.0008). The median time to change or discontinuation was more rapid in those started on a NOAC vs warfarin (97 days vs. 122 days, p=0.003). Among those on warfarin at baseline, 7.6% (n=52) were switched to a NOAC within 6 months, whereas transitions from NOAC to warfarin was 2.5% (n=42).Transitions among NOACs occurred in 9.8%, 3.2%, and 5.5% of patients on baseline dabigatran, rivaroxaban, and apixaban, respectively. Physician preference was the most common reason for both OAC and warfarin changes (Table). Drug cost was the primary reason for change of therapy in 15% of NOAC users (vs. 0 for warfarin). Conclusions: At 6-month follow-up, one in five newly started on OAC had discontinued or changed. These rates of change were similar among warfarin and NOAC treated patients. Cost concerns drove discontinuation in a modest number of patients, however, cost concerns were more prevalent in NOAC-treated patients.

Background: Non-vitamin K oral anticoagulants (NOACs) are effective at preventing stroke in patients with atrial fibrillation (AF). However, little is known about the frequency of major bleeds on NOACs and how these events are managed in clinical practice. Methods: We assessed the rates, management, and outcomes of ISTH major bleeding events among AF patients in the ORBIT-AF II registry (mean follow-up 213 days). Results: Overall, 103 patients experienced 110 major bleeding events during follow-up n=90/4986 (1.8%) on NOAC, and n=20/1320 (1.5%) on warfarin. Patients with bleeding events on NOAC were slightly younger than those on warfarin (median age 76 vs. 80; p=0.2). Among mutually-exclusive bleeding types, intracranial bleeding was more common in warfarin treated patients than NOAC-treated (15% vs 6.7%), whereas GI bleeding was more common on NOACs (56% vs. 40%, overall p=0.1 for bleeding type). Management of bleeding differed by anticoagulation type: blood products and reversal agents were more commonly used in patients on warfarin (Table). No patient received prothrombin complexes, recombinant factor VIIa, aminocaproic acid, tranexamic acid, aprotinin, or desmopressin. Out of 90 major bleeding events in NOAC patients, only 1 was fatal (1%). Within 30 days following bleeding, there were no strokes and 1 TIA (NOAC). Following a major bleed, the recurrent bleeding rate in NOAC patients in the next 30-days was 4% and the death rate was 4%. Conclusions: Rates of major bleeding with NOACs in clinical practice are comparable to those reported in clinical trials. Compared with warfarin, bleeding among NOAC users was less likely intracranial and more likely to be GI. Management of bleeding in the setting of NOAC rarely includes reversal agents.

Background: With increasing options for treating atrial fibrillation (AF), it is important to understand and quantify patient symptoms and quality of life (QoL), as improving symptoms and maximizing QoL are primary treatment goals. However, little is known about the factors associated with QoL. Methods: The Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) is a disease-specific QoL tool for AF, with domain and summary scores ranging from 0 (the worst health status) to 100. Using hierarchical pseudo-binomial regression, we evaluated factors associated with baseline AFEQT Summary and Subscale scores in the ORBIT AF registry. Adjusted associations were reported as odds ratios (OR) and 95% confidence intervals (CI). Results: AFEQT was assessed in 2,007 AF outpatients from 99 sites. Median age and interquartile range (IQR) was 76 (67-82); 43% were female; and the median CHA2DS2-VASC score was 4 (3-5). Median AFEQT summary score was 82 (67, 94). Median symptom score was 92 (78-100) and daily activity score was 77 (52-94). Female sex, younger age, new onset AF, higher heart rate, obstructive sleep apnea, and CAD were all associated with reduced QoL. (Table) Similar trends were seen for the symptoms subscale: female sex [OR 0.57 CI (0.48, 0.68)], younger age [OR 1.10 CI (1.06, 1.15)], and new onset AF [OR 0.55 CI (0.43, 0.70)] were associated with worse symptoms. Likewise, for the daily activities subscale, Other race [OR 0.54 CI (0.36-0.80)] and higher BMI [OR 0.98 CI (0.98-0.99)] were associated with decreased activity. Conclusions: In the largest community-based assessment of QoL in patients with AF, we found several patient factors to be associated with low QoL, including female sex, new onset AF, younger age, higher heart rate, and certain cardiopulmonary comorbidities. Understanding patient characteristics associated with worse QoL can be a foundation for eradicating disparities and tailoring treatment.