Chang, Paul

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.

Background: The use of evidence-based therapies to treat cardiovascular comorbidities and risk factors in patients with AF in outpatient clinical practice has not been well characterized. Methods: Using a large, community-based registry of patients with AF in the United States, the prevalence of cardiovascular comorbidities and corresponding use of evidence-based therapies were determined. Results: Among 9,589 enrolled patients with AF, the median age was 75 years; 57.8% were male; 10.7% were non-white; 69.9% had Medicare or Medicaid; 31.8% had coronary heart disease, 32.2% had heart failure, 13.0% had peripheral vascular disease, and 29.5% had diabetes mellitus. Among eligible patients, 62.8% of 3,612 were prescribed an antiplatelet agent, 72.1% of 4,674 were prescribed a β-blocker, 59.7% of 5,121 were prescribed an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, 15.7% of 624 were prescribed an aldosterone antagonist, 70.1% of 6,914 were prescribed a statin, 94.7% of 8,329 were prescribed an antihypertensive, 58.3% of 504 had an ICD, and 44.5% of 9,589 received all indicated evidence-based therapies ( Table ). Conclusion: Cardiovascular comorbidities and risk factors in patients with AF are often inadequately treated with evidence-based therapies in the outpatient practice setting, underscoring opportunities to improve care for patients with AF.

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: Patients with sinus node dysfunction (SND) are at increased risk of atrial tachyarrhythmias, including atrial fibrillation (AF). Whether the presence of SND is also associated with worse outcomes among those with AF has not been well described. Methods: The ORBIT-AF registry enrolled patients with AF from a range of clinical practices across the US. SND was defined clinically, based on the presence of sinus bradycardia, severe sinus bradycardia, sinus arrest, sinoatrial exit block, or features of tachycardia-bradycardia syndrome. Descriptive statistics and multivariable logistic regression analysis were used to describe treatment patterns and outcomes for patients with and without SND and AF. Results: Overall, 1,710 (17.7%) patients had SND at enrollment. Patients with SND had lower left-ventricular ejection fractions, higher CHA 2 DS 2 -VASc risk scores, and more prior cerebrovascular events. Patients with SND had more severe symptoms (EHRA class IV: 17.5% vs. 13.9%; p=0.007) and poorer quality of life (median AFEQT 77.5 vs. 81.1; p=0.008) as compared to those without. SND patients were more frequently treated with oral anticoagulants (79.2% vs. 75.9%, p=0.004) and had more often received interventional therapy for AF (16.1% vs. 10.5%, p<0.0001). There were no differences in the current AF management strategy between patients with SND and those without [rate control (69.7% vs. 67.7%), rhythm control (30.0% vs. 32.0%); P=0.11]. After adjustment, significantly more patients with SND had progressed from paroxysmal AF at baseline to persistent or permanent AF at any follow-up or persistent AF at baseline to permanent AF at any follow-up than those without (OR 1.23, 95% CI 1.01-1.49, p=0.035). Conclusion: Sinus node dysfunction is associated worse symptoms, lower quality of life, and higher risk of progression to permanent AF. However, SND is not associated with increased risk of all-cause hospitalization, incident stroke, or all-cause death.

ABSTRACTBackgroundPatients with sinus node dysfunction (SND) have increased risk of atrial tachyarrhythmias, including atrial fibrillation (AF). To date, treatment patterns and outcomes of patients with SND and AF have not been well described.HypothesisPatients with SND and AF have higher risk of adverse cardiovascular outcomes.MethodsSinus node dysfunction was defined clinically, based on treating physician. Treatment patterns were described and logistic regression analysis performed to assess outcomes.ResultsOverall, 1710 (17.7%) out of 9631 patients had SND at enrollment. Patients with SND and AF had increased comorbid medical illnesses, more severe symptoms (European Heart Rhythm Association class IV: 17.5% vs 13.9%; P = 0.0007), and poorer quality of life (median 12‐month Atrial Fibrillation Effect on Quality of Life score: 79.6 vs 85.2; P = 0.0008). There were no differences in AF management strategy between patients with SND and those without (rate control, 69.7% vs 67.7%; rhythm control, 30.0% vs 32.0%; P = 0.11). After adjustment, patients with SND were more likely than those without SND to progress from paroxysmal AF at baseline to persistent or permanent AF at any follow‐up, or persistent AF at baseline to permanent AF at any follow‐up (odds ratio: 1.23, 95% confidence interval: 1.01‐1.49, P = 0.035). However, there was no association between SND and major risk‐adjusted outcomes.ConclusionsSinus node dysfunction is present in 1 of 6 patients with AF and is associated with increased comorbidities and higher symptom burden. However, SND is not associated with an increase in major risk‐adjusted outcomes.

Background Most patients with atrial fibrillation ( AF ) require rate control; however, the optimal target heart rate remains under debate. We aimed to assess rate control and subsequent outcomes among patients with permanent AF . Methods and Results We studied 2812 US outpatients with permanent AF in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation. Resting heart rate was measured longitudinally and used as a time‐dependent covariate in multivariable Cox models of all‐cause and cause‐specific mortality during a median follow‐up of 24 months. At baseline, 7.4% (n=207) had resting heart rate <60 beats per minute (bpm), 62% (n=1755) 60 to 79 bpm, 29% (n=817) 80 to 109 bpm, and 1.2% (n=33) ≥110 bpm. Groups did not differ by age, previous cerebrovascular disease, heart failure status, CHA 2 DS 2 ‐ VAS c scores, renal function, or left ventricular function. There were significant differences in race ( P =0.001), sinus node dysfunction ( P =0.004), and treatment with calcium‐channel blockers ( P =0.006) and anticoagulation ( P =0.009). In analyses of continuous heart rates, lower heart rate ≤65 bpm was associated with higher all‐cause mortality (adjusted hazard ratio [ HR ], 1.15 per 5‐bpm decrease; 95% CI , 1.01 to 1.32; P =0.04). Similarly, increasing heart rate >65 bpm was associated with higher all‐cause mortality (adjusted HR , 1.10 per 5‐bpm increase; 95% CI , 1.05 to 1.15; P <0.0001). This relationship was consistent across endpoints and in a broader sensitivity analysis of permanent and nonpermanent AF patients. Conclusions Among patients with permanent AF , there is a J‐shaped relationship between heart rate and mortality. These data support current guideline recommendations, and clinical trials are warranted to determine optimal rate control. Clinical Trial Registration URL : http://clinicaltrials.gov/ . Unique identifier: NCT01165710.

Background— Instruments to assess symptom burden and quality of life among patients with atrial fibrillation (AF) have not been well evaluated in community practice or associated with patient outcomes. Methods and Results— Using data from 10 087 AF patients in the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF), symptom severity was evaluated using the European Heart Rhythm Association (EHRA) classification system, and quality of life was assessed using the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire. The association between AF-related symptoms, quality of life, and outcomes was assessed using Cox regression. The majority of AF patients (61.8%) were symptomatic (EHRA >2) and 16.5% had severe or disabling symptoms (EHRA 3–4). EHRA symptom class was well correlated with the AFEQT score (Spearman correlation coefficient −0.39). Over 1.8 years of follow-up, AF symptoms were associated with a higher risk of hospitalization (adjusted hazard ratio for EHRA ≥2 versus EHRA 1 1.23, 95% confidence interval, 1.15–1.31) and a borderline higher risk of major bleeding. Lower quality of life was associated with a higher risk of hospitalization (adjusted hazard ratio for lowest quartile of AFEQT versus highest 1.49, 95% confidence interval, 1.2–1.84), but not other major adverse events, including death. Conclusions— In a community-based study, most patients with AF were symptomatic and had impaired quality of life. Quality of life measured by the AFEQT correlated closely with symptom severity measured by the EHRA class. AF symptoms and lower quality of life were associated with higher risk of hospitalization but not mortality during follow-up.

Background The characteristics of patients undergoing atrial fibrillation ( AF ) ablation and subsequent outcomes in community practice are not well described. Methods and Results Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation ( ORBIT ‐ AF ), we investigated the prevalence and impact of catheter ablation of AF . Among 9935 patients enrolled, 5.3% had previous AF ablation. Patients with AF ablation were significantly younger, more frequently male, and had less anemia, chronic obstructive pulmonary disease, and previous myocardial infarction (P<0.05 for all analyses) than those without previous catheter ablation of AF . Ablated patients were more likely to have a family history of AF , obstructive sleep apnea, paroxysmal AF , and moderate‐to‐severe symptoms (P<0.0001 for all analyses). Patients with previous ablation were more often in sinus rhythm on entry into the registry (52% vs. 32%; P<0.0001). Despite previous ablation, 46% in the ablation group were still on antiarrhythmic therapy. Oral anticoagulation was prescribed in 75% of those with previous ablation versus 76% in those without previous ablation (P=0.5). The adjusted risk of death (hazard ratio [ HR ], 0.78; 95% confidence interval [ CI ], 0.52 to 1.18; P=0.2) and cardiovascular ( CV ) hospitalization ( HR , 1.06; 95% CI , 0.90 to 1.26; P=0.5) were similar in both groups. Patients with incident AF ablation had higher risk of subsequent CV hospitalization than matched patients without incident ablation ( HR , 1.67; 95% CI , 1.24 to 2.26; P=0.0008). Conclusions In U.S. clinical practice, a minority of patients with AF are managed with catheter ablation. Subsequent to ablation, there were no significant differences in oral anticoagulation use or outcomes, including stroke/non–central nervous system embolism/transient ischemic attack or death. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01165710.