Holmes, DaJuanicia N.

Background: Dabigatran is a novel oral anticoagulant approved in October 2010 for thromboprophylaxis in atrial fibrillation (AF), yet patterns of adoption of this novel agent in clinical practice are unknown. Methods: Using the ORBIT-AF Registry, a national outpatient prospective AF registry involving 170 sites, we examined patterns of those switching to dabigatran from warfarin from 2010 to 2012. Results: Of 7,066 patients with AF receiving warfarin at baseline, 511 (7%) were switched to dabigatran during follow-up. Patients switched to dabigatran were younger (median age 73 vs. 76, p<0.0001), more likely to be White (94% vs. 89%, p=0.001), and had better kidney function (median creatinine clearance (CrCl) 77 mL/min vs. 69 mL/min, p<0.0001), but less likely to have a history of anemia, (14% vs. 18%, p=0.009) or history of any cerebrovascular disease (14% vs. 17%, p=0.04) or CAD (22% vs. 34%, p<0.0001) or be followed in an anticoagulation clinic (36% vs. 45%, p<0.0001). Patients switched to dabigatran were more likely to have been recently diagnosed with AF (5.3% vs. 3.0%, p=0.03), and their CHADS 2 scores were significantly lower (p<0.0001). Conclusions: Patients receiving warfarin who were switched to dabigatran were younger, with lower CHADS 2 scores, better kidney function, and less concomitant cardiovascular disease than those not switched. This conservative transition pattern suggests greater physician emphasis on bleeding avoidance than on stroke risk reduction.

Background. Oral anticoagulation therapy (OAC) reduces the risk of thromboembolic events associated with atrial fibrillation (AF), yet a substantial proportion of patients with AF are not prescribed OAC. The frequencies of and factors associated with contraindications to OAC therapy in clinical practice are not well-described. Methods. We used data from the ORBIT-AF study, a national, prospective, outpatient registry of incident and prevalent AF. OAC contraindications were uniformly collected at study enrollment by site personnel. Patient and provider characteristics were compared between participants with documented OAC contraindications at baseline and those without OAC contraindications. Results. From June 2010 to August 2011, 10124 patients ≥18 years old with electrocardiographically documented AF were enrolled at 176 practices. Of these, 1409 (13.9%) had OAC contraindications documented at the baseline visit: prior bleed (26.2%), patient refusal/preference (26.0%), high bleeding risk (22.6%), frequent falls/frailty (16.6%), other (11.9%), need for dual antiplatelet therapy (9.8%), unable to adhere/monitor warfarin (5.7%), comorbid illness (5.0%), prior intracranial hemorrhage (4.7%), allergy (2.3%), occupational risk (0.8%), and pregnancy (0.2%). Compared to patients without contraindications, those with contraindications had higher stroke risk (CHADS2>2) and were older, more likely to be female, more likely to be seen by a cardiologist and less likely to be seen by an electrophysiologist (Table 1). Among those patients with reported contraindications, 28.4% were taking warfarin. Conclusions. Contraindications to OAC therapy among AF patients are common and often due to high bleeding risk. Furthermore, many patients with reported contraindications are taking warfarin, suggesting that many contraindications to warfarin therapy are minor, relative, or temporary.

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 Cardioversion is common among patients with atrial fibrillation (AF). We hypothesised that novel oral anticoagulants (NOAC) used in clinical practice resulted in similar rates of stroke compared with vitamin K antagonists (VKA) for cardioversion. Methods Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II, patients with AF who had a cardioversion, follow-up data and an AF diagnosis within 6 months of enrolment were identified retrospectively. Clinical outcomes were compared for patients receiving a NOAC or VKA for 1 year following cardioversion. Results Among 13 004 patients with AF, 2260 (17%) underwent cardioversion. 1613 met the inclusion criteria for this analysis. At the time of cardioversion, 283 (17.5%) were receiving a VKA and 1330 (82.5%) a NOAC. A transoesophageal echocardiogram (TOE) was performed in 403 (25%) cardioversions. The incidence of stroke/transient ischaemic attack (TIA) at 30 days was the same for patients having (3.04 per 100 patient-years) or not having (3.04 per 100 patient-years) a TOE (p=0.99). There were no differences in the incidence of death (HR 1.19, 95% CI 0.62 to 2.28, p=0.61), cardiovascular hospitalisation (HR 1.02, 95% CI 0.76 to 1.35, p=0.91), stroke/TIA (HR 1.18, 95% CI 0.30 to 4.74, p=0.81) or bleeding-related hospitalisation (HR 1.29, 95% CI 0.66 to 2.52, p=0.45) at 1 year for patients treated with either a NOAC or VKA. Conclusions Cardioversion was a low-risk procedure for patients treated with NOAC, and there were statistically similar rates of stroke/TIA 30 days after cardioversion as for patients treated with VKA. There were no statically significant differences in death, stroke/TIA or major bleeding at 1 year among patients treated with NOAC compared with VKA after cardioversion.

Background: Patients with atrial fibrillation on oral anticoagulation (OAC) undergoing cardiac catheterization face risks for embolic and bleeding events, yet information on strategies to mitigate these risks in contemporary practice is lacking. Methods: We aimed to describe the clinical/procedural characteristics of a contemporary cohort of patients with atrial fibrillation on OAC who underwent cardiac catheterization. Use of bleeding avoidance strategies and bridging therapy were described and outcomes including death, stroke, and major bleeding at 30 days and 1 year were compared by OAC type. Results: Of 13 404 patients in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II Registry from 2013 to 2016, 741 underwent cardiac catheterization (139 with percutaneous coronary intervention) in the setting of OAC. The patients’ median age was 71, 61.8% were male, white (87.2%), had hypertension (83.7%), hyperlipidemia (72.1%), diabetes mellitus (31.6%), and chronic kidney disease (28.2%); 20.2% received warfarin while 79.8% received direct acting oral anticoagulant. One third of patients underwent radial artery access, and bivalirudin was used in 4.6%. Bridging therapy was used more often in patients on warfarin versus direct acting oral anticoagulant (16.7% versus10.0%). OAC was interrupted in 93.8% of patients. Patients on warfarin versus direct acting oral anticoagulant were equally likely to restart OAC (58.0% versus 60.7%), had similar use of antiplatelet therapy (44.0% versus 41.3%) after catheterization, and had similar rates of myocardial infarction and death at 1 year, but higher rates of major bleeding (43.3 versus 12.9 events/100 patient years) and stroke (4.9 versus 1.9 events/100 patient years). Conclusions: In a real-world registry of patients with atrial fibrillation undergoing cardiac catheterization, most cases are elective, performed by femoral access, with interruption of OAC. Bleeding avoidance strategies such as radial artery access and bivalirudin were used infrequently and use of bridging therapy was uncommon. Nearly 40% of patients did not restart OAC postprocedure, exposing patients to risk for stroke. Further research is necessary to optimize the management of patients with atrial fibrillation undergoing cardiac catheterization.

Background: Atrial fibrillation (AF) adversely impacts health-related quality of life (hrQoL). While some patients demonstrate improvements in hrQoL, the factors associated with large improvements in hrQoL are not well described. Methods: We assessed factors associated with a 1-year increase in the Atrial Fibrillation Effect on Quality-of-Life score of 1 SD (≥18 points; 3× clinically important difference), among outpatients in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation I registry. Results: Overall, 28% (181/636) of patients had such a hrQoL improvement. Compared with patients not showing large hrQoL improvement, they were of similar age (median 73 versus 74, P =0.3), equally likely to be female (44% versus 48%, P =0.3), but more likely to have newly diagnosed AF at baseline (18% versus 8%; P =0.0004), prior antiarrhythmic drug use (52% versus 40%, P =0.005), baseline antiarrhythmic drug use (34.8% versus 26.8%, P =0.045), and more likely to undergo AF-related procedures during follow-up (AF ablation: 6.6% versus 2.0%, P =0.003; cardioversion: 12.2% versus 5.9%, P =0.008). In multivariable analysis, a history of alcohol abuse (adjusted OR, 2.41; P =0.01) and increased baseline diastolic blood pressure (adjusted OR, 1.23 per 10-point increase and >65 mm Hg; P =0.04) were associated with large improvements in hrQoL at 1 year, whereas patients with prior stroke/transient ischemic attack, chronic obstructive pulmonary disease, and peripheral arterial disease were less likely to improve ( P <0.05 for each). Conclusions: In this national registry of patients with AF, potentially treatable AF risk factors are associated with large hrQoL improvement, whereas less reversible conditions appeared negatively associated with hrQoL improvement. Understanding which patients are most likely to have large hrQoL improvement may facilitate targeting interventions for high-value care that optimizes patient-reported outcomes in AF. Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01165710.

Objective Non-vitamin K oral anticoagulants (NOACs) require dose adjustment for renal function. We sought to investigate change in renal function over time in patients with atrial fibrillation (AF) and whether those on NOACs have appropriate dose adjustments according to its decline. Methods We included patients with AF enrolled in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II registry treated with oral anticoagulation. Worsening renal function (WRF) was defined as a decrease of >20% in creatinine clearance (CrCl) from baseline. The US Food and Drug Administration (FDA)-approved package inserts were used to define the reduction criteria of NOACs dosing. Results Among 6682 patients with AF from 220 sites (median age (25th, 75th): 72.0 years (65.0, 79.0); 57.1% male; median CrCl at baseline: 80.1 mL/min (57.4, 108.5)), 1543 patients (23.1%) experienced WRF with mean decline in CrCl during 2 year follow-up of −6.63 mL/min for NOACs and −6.16 mL/min for warfarin. Among 4120 patients on NOACs, 154 (3.7%) patients had a CrCl decline sufficient to warrant FDA-recommended dose reductions. Of these, NOACs dosing was appropriately reduced in only 31 (20.1%) patients. Compared with patients with appropriately reduced NOACs, those without were more likely to experience bleeding complications (major bleeding: 1.7% vs 0%; bleeding hospitalisation: 2.6% vs 0%) at 1 year. Conclusions In the US practice, about one-fourth of patients with AF had >20% decline in CrCl over time during 2 year follow-up. As a result, about 3.7% of those treated with NOACs met guideline criteria for dose reduction, but of these, only 20.1% actually had a reduction.

Background: The Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire has recently been validated to measure the impact of atrial fibrillation on quality of life, but a clinically important difference in AFEQT score has not been well defined. Methods and Results: To determine the clinically important difference in overall AFEQT (score range= 0 [worst] to 100 [best]) and selected subscales, we analyzed data in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry, a United States-based outpatient atrial fibrillation registry. AFEQT was assessed at baseline and 1 year in a subset of 1347 ORBIT-AF patients from 80 US sites participating in ORBIT-AF from June 2010 to August 2011. The mean change method was used to relate changes in 1-year AFEQT scores to clinically important changes in the physician assessment of European Heart Rhythm Association functional status (1 class improvement and separately 1 class deterioration). Clinically important differences and 95% CI corresponding to either a 1 European Heart Rhythm Association class improvement or deterioration were 5.4 (3.6–7.2) and −4.2 (−6.9 to −1.5) AFEQT points, respectively. Similarly, clinically important difference values were seen for a 1 European Heart Rhythm Association class improvement for the AFEQT subscales Activities of Daily Living and Symptoms: 5.1 (2.5–7.6) and 7.1 (5.3–9.0) AFEQT points, respectively. Conclusions: Based on the anchor of 1 European Heart Rhythm Association class change, changes in AFEQT score of + or −5 points are clinically important changes in patients’ health. Clinical Trial Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT01165710.

Background Chronic kidney disease ( CKD ) is a common comorbidity in patients with atrial fibrillation. The presence of CKD complicates drug selection for stroke prevention and rhythm control. Methods and Results Patients enrolled in ORBIT AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) with baseline renal function and follow‐up data were included (N=9019). CKD was defined as an estimated creatinine clearance <60 mL /min. Patient characteristics were compared by CKD status, and Cox proportional hazards modeling was used to examine the association between oral anticoagulant ( OAC ) use and outcomes and antiarrhythmic drug use and outcomes stratified by CKD stages. At enrollment, 3490 (39%) patients had an estimated creatinine clearance <60 mL /min. Patients with CKD were older and had higher CHA 2 DS 2 VAS c and Anticoagulant and Risk Factors in Atrial Fibrillation (ATRIA) scores. A rhythm control strategy was selected less frequently in patients with CKD , while OAC use was lower among Stage IV and V CKD patients. After adjustment, no significant interaction was noted for OAC and CKD on all‐cause mortality ( P =0.5442) or cardiovascular death ( P =0.1233), although a trend for increased major bleeding ( P =0.0608) and stroke, systemic embolism or transient ischemic attack ( P =0.0671) was observed. No interaction was noted for antiarrhythmic drug use and CKD status on all‐cause mortality ( P =0.9706), or stroke, systemic embolism or transient ischemic attack ( P =0.4218). Conclusions Patients with atrial fibrillation and CKD are less likely to be treated with rhythm control. Patients with advanced CKD are less likely to receive OAC . Finally, outcomes with OAC in patients with advanced CKD may be materially different with higher rates of both bleeding and stroke.