Singer, Daniel E.

Background Non–vitamin K antagonist oral anticoagulants (NOACs) are indicated for stroke prevention in atrial fibrillation (AF) but require lower doses in certain patients. We sought to describe the frequency, appropriateness (according to Food and Drug Administration labeling), and outcomes of patients prescribed reduced doses of NOACs in community practice. Methods and Results We analyzed data from the ORBIT‐AF II (The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II) registry, a prospective, national, observational registry of AF patients. Among 7925 AF patients receiving NOACs, we assessed patterns of use of reduced NOAC doses and associated cardiovascular and bleeding outcomes at median follow‐up of 1 year. Overall, 6636 patients (84%) received a NOAC at standard dose, which was consistent with US Food and Drug Administration labeling in 6376 (96%). Reduced NOAC dose was prescribed to 1289 (16% overall), which was consistent with Food and Drug Administration labeling in only 555 patients (43%). Compared with those whose NOAC dose was appropriately reduced, patients receiving inappropriate dose reductions were younger (median age 79 versus 84, P <0.0001) and had lower ORBIT bleeding risk scores (26% ≥4 versus 45%, P <0.0001). Compared with those appropriately receiving standard dosing, patients receiving inappropriately reduced‐dose NOACs had higher unadjusted rates of thromboembolic events (2.11 versus 1.35 events per 100 patient years, hazard ratio 1.56, 95% confidence interval 0.92‐2.67) and death (6.77 versus 2.60, hazard ratio 2.61, 95% confidence interval 1.86‐3.67). After adjustment, outcomes were not significantly different but tended to favor patients dosed appropriately. Conclusions The majority of dose reductions of NOACs in AF are inconsistent with US Food and Drug Administration recommendations. There appear to be opportunities to improve current NOAC dosing in community practice. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01701817.

Background The presence of valvular heart disease ( VHD ) may affect the risk of stroke and mortality in patients with atrial fibrillation ( AF ). Community‐based estimates of prevalence and outcomes of specific forms of VHD in patients with AF are lacking. Methods and Results We examined the prevalence of VHD , anticoagulation use, mortality, stroke/transient ischemic attack, and bleeding among a community cohort of patients with AF . Significant VHD was defined as follows: (1) moderate/severe mitral stenosis or mechanical valve; (2) bioprosthetic valve, surgical repair, or balloon valvuloplasty; and (3) moderate/severe aortic regurgitation or stenosis, mitral regurgitation, or tricuspid regurgitation. Proportional hazards models were performed to test the association between VHD groups and outcomes. Among 9748 patients with AF , 2705 (27.7%) had significant VHD . Anticoagulation use was highest among patients with mitral stenosis/mechanical valve (91.8%). Compared with individuals with no significant VHD , individuals with aortic regurgitation/aortic stenosis, mitral regurgitation, or tricuspid regurgitation (hazard ratio, 1.23; 95% confidence interval, 1.07–1.42) had the highest risk of death. There were no differences in stroke or transient ischemic attack and major bleeding among individuals with and without significant VHD . Patients with AF and aortic stenosis had the highest risk of death (hazard ratio, 1.32; 95% confidence interval, 1.08–1.62). Conclusions Significant VHD is common among patients with AF in community practice. In a community cohort of patients with AF and CHA 2 DS 2 ‐ VAS c score ≥2, most were anticoagulated. Individuals with AF and moderate‐to‐severe biological VHD have more comorbidities and a higher mortality risk; however, stroke and major bleeding are similar among those with and without significant VHD .

Objective To describe self-reported disease understanding for newly diagnosed patients with atrial fibrillation (AF) and assess (1) how disease understanding changes over the first 6 months after diagnosis and (2) the relationship between patient understanding of therapies at baseline and treatment receipt at 6 months among treatment-naïve patients. Methods We analysed survey data from SATELLITE (Survey of Patient Knowledge and Personal Priorities for Treatment), a substudy of patients with new-onset AF enrolled in the national Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT) II registry across 56 US sites. Patients were surveyed at the baseline and 6-month follow-up clinic visits using Likert scales. Results Among 1004 baseline survey responses, patients’ confidence in their understanding of rhythm control, ablation, anticoagulation and cardioversion was suboptimal, with ‘high’ understanding ranging from 8.5% for left atrial appendage closure to 71.3% for rhythm therapy. Of medical history and demographic factors, education level was the strongest predictor of reporting ‘high’ disease understanding. Among the 786 patients with 6-month survey data, significant increases in the proportion reporting high understanding were observed (p<0.05) only for warfarin and direct oral anticoagulants (DOACs). With the exception of ablation, high understanding for a given therapeutic option was not associated with increased use of that therapy at 6 months. Conclusions About half of patients with new-onset AF understood the benefits of oral anticoagulant at the time of diagnosis and understanding improved over the first 6 months. However, understanding of AF treatment remains suboptimal at 6 months. Our results suggest a need for ongoing patient education. Clinical trial registration Clinicaltrials.gov. Identifier: NCT01701817.

Background Dabigatran is a novel oral anticoagulant approved for thromboprophylaxis in atrial fibrillation. Adoption patterns of this new agent in community practice are unknown. Methods and Results We studied patterns of dabigatran use among patients enrolled in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT‐AF) Registry between June 2010 and August 2011 and followed for 12 months. Among 9974 atrial fibrillation patients included, 1217 (12%) were treated with dabigatran during the study. Overall, patients receiving dabigatran were younger (median age 72 versus 75 years, P <0.0001), more likely to be white (92% versus 89%, P =0.005), more likely to have private insurance (33% versus 25%, P <0.0001), and less likely to have prior cardiovascular disease (4% versus 33%, P <0.0001). They had more new‐onset atrial fibrillation (8.8% versus 4.1%, P <0.0001), lower CHADS 2 scores (estimated risk based on the presence of congestive heart failure, hypertension, aged ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack; mean 2.0 versus 2.3, P <0.0001), and lower Anticoagulation and Risk Factors in Atrial Fibrillation scores (mean 2.4 versus 2.8, P <0.0001). More than half (n=14/25, 56%) of patients with severe kidney disease were not prescribed reduced dosing, whereas 10% (n=91/920) with preserved renal function received lower dosing. Among patients not on dabigatran at baseline, 8% had dabigatran initiated during follow‐up. Patient education was significantly associated with switching from warfarin to dabigatran (adjusted odds ratio for postgraduate 1.73, P =0.007), whereas antiarrhythmic drug use significantly correlated with de novo adoption of dabigatran (adjusted odds ratio 2.4, P <0.0001). Conclusions Patients receiving dabigatran were younger and at a lower risk of stroke and bleeding. Patients appeared to drive switching from warfarin, whereas clinical characteristics influenced de novo start of dabigatran. These data suggest cautious early uptake of dabigatran, and more careful attention to dosing adjustments is warranted. Clinical Trial Registration URL : Clinicaltrials.gov. Unique identifier: NCT 01165710.

Background— Patients with atrial fibrillation (AF) at the highest stroke risk derive the largest benefit from oral anticoagulation (OAC). Those with the highest stroke risk have been paradoxically less likely to receive OAC. This study assessed the association between stroke and bleeding risk on rates of OAC. Methods and Results— We analyzed OAC use among 10 098 patients with AF from 174 community-based outpatient practices enrolled in 2010–2011 in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). OAC was defined as warfarin or dabigatran use at study enrollment. Stroke and bleeding risk were calculated using congestive heart failure, hypertension, age, diabetes mellitus, prior stroke (CHADS 2 ), and anticoagulation and risk factors in AF (ATRIA) scores, respectively. The mean subject age was 73 years; 58% were men. Overall, 76% of patients received OAC (71% warfarin and 5% dabigatran). The use of OAC increased among those with higher CHADS 2 scores, from 53% for CHADS 2 =0 to 80% for CHADS 2 ≥2 ( P <0.001). OAC use fell slightly with increasing ATRIA bleeding risk score, from 81% for ATRIA=3 to 73% for ATRIA≥5 ( P <0.001). A significant interaction existed between ATRIA and CHADS 2 scores ( P =0.021). Among those with low bleeding risk, use of OAC increased significantly with increasing stroke risk. Among those with high bleeding risk, CHADS 2 stroke risk had a smaller impact on use of OAC. Conclusions— In community-based outpatients with AF, use of OAC was high and driven by not only predominantly stroke but also bleeding risk. Stroke risk significantly affects OAC use among those with low bleeding risk, whereas those with high bleeding risk demonstrate consistently lower use of OAC regardless of stroke risk.