Anticoagulation is highly effective for the prevention of stroke in patients with atrial fibrillation (AF) but it is dependent on patients continuing therapy. While studies have demonstrated suboptimal therapeutic persistence on warfarin, few have studied persistence rates with non vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran. We examined rates of continued use of dabigatran versus warfarin over 1 year among AF patients in the ORBIT-AF registry between June 29, 2010 and August 09, 2011. Multivariable logistic regression analysis was used to identify characteristics associated with 1-year persistent use of dabigatran therapy or warfarin. At baseline, 6.4 and 93.6% of 7150 AF patients were on dabigatran and warfarin, respectively. At 12 months, dabigatran-treated patients were less likely to have continued their therapy than warfarin-treated patients [Adjusted persistence rates: 66% (95% CI 60-72) vs. 82% (95% CI 80-84), p < .0001]. Predictors of dabigatran persistence included: CHA₂DS₂-VASc risk scores ≥ 2 OR 5.69, (95% CI 1.50-21.6) and BMI greater than 25 mg/m² but less than 38 kg/m² 1.05 (1.01-1.09). Predictors of persistence on warfarin included: African American race (vs. White) 1.53 (1.07-2.19), Hispanic ethnicity (vs. White) 1.66 (1.06-2.60), paroxysmal and persistent AF (vs. new-onset) 1.68 (1.21-2.33) and 1.91 (1.35-2.69) respectively, LVH 1.40 (1.08-1.81), and CHA₂DS₂-VASc risk scores ≥ 2 1.94 (1.18-3.19). While 1-year persistence rates for dabigatran were lower than warfarin, persistence rates for both agents were not ideal. Future studies evaluating contemporary persistence are needed in order to assist in better targeting interventions aimed to improve anticoagulation persistence.

Mineralocorticoid receptor antagonist (MRA) therapy may be beneficial to patients with atrial fibrillation (AF), but little is known about their use in patients with AF and subsequent outcomes. In order to better understand MRA use and subsequent outcomes, we performed a retrospective cohort study of the contemporary ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registry. AF progression and cardiovascular outcomes were compared using propensity-matched Cox proportional hazards modeling according to MRA use at baseline and new MRA use at follow-up versus patients with no MRA use. Among 7012 patients with nonpermanent AF, 320 patients were taking MRA at enrollment, and 416 patients initiated MRA use during follow-up. The mean patient age was 72.5 years, 56.3% were men, and 70.4% had paroxysmal AF. Among all patients taking MRAs, 434 (59.0%) had heart failure, 655 (89.0%) had hypertension, and 380 (51.6%) had both. After adjustment, new MRA use was not associated with reduced AF progression (hazard ratio, 1.18; 95% confidence interval, 0.88-1.58; P=0.27) but showed a trend towards lower risk of stroke, transient ischemic attack, or systemic embolism (hazard ratio, 0.17; 95% confidence interval, 0.02-1.23; P=0.08). Results were similar for a comparison of new MRA users and baseline MRA users compared with nonusers. In community-based outpatients with AF, the majority of MRA use was for heart failure and hypertension. MRA use also trended towards lower adjusted stroke risk. Future studies should test the hypothesis that MRA use may decrease the risk of stroke in patients with AF.

Background

Recent clinical trials have demonstrated the safety and efficacy of several non-vitamin K oral anticoagulants (NOACs) for the treatment of atrial fibrillation (AF). However, there are limited data on their use and outcomes in routine clinical practice, particularly among patients newly diagnosed as having AF and patients with AF recently transitioned to a NOAC.

Methods/design

ORBIT-AF II is a multicenter, national registry of patients with AF that is enrolling up to 15,000 newly diagnosed patients with AF and/or those with AF recently transitioned to a NOAC from 300 US outpatient practices. These patients will be followed for up to 2 years, including clinical status, outcomes (major adverse cardiovascular events, bleeding), and management of anticoagulation surrounding bleeding events. In addition, detailed data regarding the use of these agents in and around cardiac procedures, their complications, and management of such complications will be collected.

Conclusions

The ORBIT-AF II registry will provide valuable insights into the safety and effectiveness of NOACs used in AF in community practice settings.

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.

Background Current American College of Cardiology/American Heart Association guidelines suggest that for patients with atrial fibrillation who are at low risk for stroke (CHA₂DS₂VASc=1) (or women with CHA₂DS₂VASc=2) a variety of treatment strategies may be considered. However, in clinical practice, patterns of treatment in these "low-risk" patients are not well described. The objective of this analysis is to define thromboembolic event rates and to describe treatment patterns in patients with low-risk CHA₂DS₂VASc scores. Methods and Results We compared characteristics, treatment strategies, and outcomes among patients with a CHA₂DS₂VASc=0, CHA₂DS₂VASc=1, females with a CHA₂DS₂VASc=2, and CHA₂DS₂VASc ≥2 in ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) I & II. Compared with CHA₂DS₂VASc ≥2 patients (84.2%), those with a CHA₂DS₂VASc=0 (60.3%), 1 (69.9%), and females with a CHA₂DS₂VASc score=2 (72.4%) were significantly less often treated with oral anticoagulation ( P<0.0001). Stroke rates were low overall and ranged from 0 per 100 patient-years in those with CHA₂DS₂VASc=0, 0.8 (95% confidence interval [CI] [0.5-1.2]) in those with CHA₂DS₂VASc=1, 0.8 (95% CI [0.4-1.6]) in females with a CHA₂DS₂VASc score=2, and 1.7 (95% CI [1.6-1.9]) in CHA₂DS₂VASc ≥2. All-cause mortality (per 100 patient-years) was highest in females with a CHA₂DS₂VASc score=2 (1.4) (95% CI [0.8-2.3]), compared with patients with a CHA₂DS₂VASc=0 (0.2) (95% CI [0.1-1.0]), and CHA₂DS₂VASc=1 (1.0) (95% CI [0.7-1.4]), but lower than patients with a CHA₂DS₂VASc ≥2 (5.7) (95% CI [5.4-6.0]). Conclusion The majority of CHA₂DS₂VASc=0-1 patients are treated with oral anticoagulation. In addition, the absolute risks of death and stroke/transient ischemic attack were low among both male and females CHA₂DS₂VASc=0-1 as well as among females with a CHA₂DS₂VASc score=2. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01701817.

Background

Comorbidities are common in patients with atrial fibrillation (AF) and affect prognosis, yet are often undertreated. However, contemporary rates of use of guideline-directed therapies (GDT) for non-AF comorbidities and their association with outcomes are not well described.

Methods

We used the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF) to test the association between GDT for non-AF comorbidities and major adverse cardiac or neurovascular events (MACNE; cardiovascular death, myocardial infarction, stroke/thromboembolism, or new-onset heart failure), all-cause mortality, new-onset heart failure, and AF progression. Adjustment was performed using Cox proportional hazards models and logistic regression.

Results

Only 6,782 (33%) of the 20,434 patients eligible for 1 or more GDT for non-AF comorbidities received all indicated therapies. Use of all comorbidity-specific GDT was highest for patients with hyperlipidemia (75.6%) and lowest for those with diabetes mellitus (43.1%). Use of "all eligible" GDT was associated with a nonsignificant trend toward lower rates of MACNE (HR 0.90 [0.79-1.02]) and all-cause mortality (HR 0.90 [0.80-1.01]). Use of GDT for heart failure was associated with a lower risk of all-cause mortality (HR 0.77 [0.67-0.89]), and treatment of obstructive sleep apnea was associated with a lower risk of AF progression (OR 0.75 [0.62-0.90]).

Conclusions

In AF patients, there is underuse of GDT for non-AF comorbidities. The association between GDT use and outcomes was strongest in heart failure and obstructive sleep apnea patients where use of GDT was associated with lower mortality and less AF progression.