Dronedarone Versus Sotalol in Antiarrhythmic Drug-Naive Veterans With Atrial Fibrillation

BACKGROUND

Sotalol and dronedarone are both used for maintenance of sinus rhythm for patients with atrial fibrillation. However, while sotalol requires initial monitoring for QT prolongation and proarrhythmia, dronedarone does not. These treatments can be used in comparable patients, but their safety and effectiveness have not been compared head to head. Therefore, we retrospectively evaluated the effectiveness and safety using data from a large health care system.

METHODS

Using Veterans Health Administration data, we identified 11 296 antiarrhythmic drug-naive patients with atrial fibrillation prescribed dronedarone or sotalol in 2012 or later. We excluded patients with prior conduction disease, pacemakers or implantable cardioverter-defibrillators, ventricular arrhythmia, cancer, renal failure, liver disease, or heart failure. We used natural language processing to identify and compare baseline left ventricular ejection fraction between treatment arms. We used 1:1 propensity score matching, based on patient demographics, comorbidities, and medications, and Cox regression to compare strategies. To evaluate residual confounding, we performed falsification analysis with nonplausible outcomes.

RESULTS

The matched cohort comprised 6212 patients (3106 dronedarone and 3106 sotalol; mean [±SD] age, 71±10 years; 2.5% female; mean [±SD] CHA2DS2-VASC, 2±1.3). The mean (±SD) left ventricular ejection fraction was 55±11 and 58±10 for dronedarone and sotalol users, correspondingly. Dronedarone, compared with sotalol, did not demonstrate a significant association with risk of cardiovascular hospitalization (hazard ratio, 1.03 [95% CI, 0.88-1.21]) or all-cause mortality (hazard ratio, 0.89 [95% CI, 0.68-1.16]). However, dronedarone was associated with significantly lower risk of ventricular proarrhythmic events (hazard ratio, 0.53 [95% CI, 0.38-0.74]) and symptomatic bradycardia (hazard ratio, 0.56 [95% CI, 0.37-0.87]). The primary findings were stable across sensitivity analyses. Falsification analyses were not significant.

CONCLUSIONS

Dronedarone, compared with sotalol, was associated with a lower risk of ventricular proarrhythmic events and conduction disorders while having no difference in risk of incident cardiovascular hospitalization and mortality. These observational data provide the basis for prospective efficacy and safety trials.

The development of a mobile app-focused deduplication strategy for the Apple Heart Study that informs recommendations for future digital trials

An app-based clinical trial enrolment process can contribute to duplicated records, carrying data management implications. Our objective was to identify duplicated records in real time in the Apple Heart Study (AHS). We leveraged personal identifiable information (PII) to develop a dissimilarity score (DS) using the Damerau-Levenshtein distance. For computational efficiency, we focused on four types of records at the highest risk of duplication. We used the receiver operating curve (ROC) and resampling methods to derive and validate a decision rule to classify duplicated records. We identified 16,398 (4%) duplicated participants, resulting in 419,297 unique participants out of a total of 438,435 possible. Our decision rule yielded a high positive predictive value (96%) with negligible impact on the trial's original findings. Our findings provide principled solutions for future digital trials. When establishing deduplication procedures for digital trials, we recommend collecting device identifiers in addition to participant identifiers; collecting and ensuring secure access to PII; conducting a pilot study to identify reasons for duplicated records; establishing an initial deduplication algorithm that can be refined; creating a data quality plan that informs refinement; and embedding the initial deduplication algorithm in the enrolment platform to ensure unique enrolment and linkage to previous records.

Alleviation of AF related symptoms following acute conversion of recent-onset, symptomatic atrial fibrillation to sinus rhythm with flecainide acetate oral inhalation solution

Introduction

Pharmacological restoration of sinus rhythm (SR) in patients with symptomatic atrial fibrillation (AF) is expected to be accompanied by prompt alleviation of symptoms to avoid the need for electrical cardioversion (ECV) and/or hospitalization. The feasibility and safety of acute cardioversion of recent-onset (≤48 hours) symptomatic AF to SR with flecainide acetate oral inhalation (FlecIH) solution was shown in the Phase 2, open-label INSTANT trial. We examined symptoms, heart rate, time to discharge and need for ECV reported among patients in the INSTANT trial whose AF was successfully converted to SR (“conversion group”; N=25) versus those whose AF did not convert to SR (“no conversion group”; N=29).

Methods

Conversion success was determined using 12-lead Holter monitoring during a 90-minute observation period. Patients in the no conversion group were offered alternative treatment per the investigator discretion. Symptoms, vital signs, time to discharge, and the need for ECV were evaluated through Day 5.

Results

Data from 54 patients (33.3% female) with a mean age of 62.1 years and a mean BMI of 26.8 kg/m2 were analyzed. All patients reported at least one AF-related symptoms at baseline (palpitations=85%; dizziness=35%; shortness of breath=37%; chest discomfort=39%) and 83.3% presented with AF symptoms ≤24 hours in duration. At 90 minutes, 80.0% of the conversion group were asymptomatic compared to 37.9% of the no conversion group (p<0.001). Mean (SD) ventricular rate at 90 minutes was 70.6 (12.5) bpm in the conversion group compared to 100.4 (29.4) bpm in the no conversion group (p<0.001). Median time to discharge was 2.3 (IQR: 0.75) hours for the conversion group compared to 3.6 (IQR: 1.02) hours for the no conversion group (p=0.001). By Day 5, 23 (79.3%) patients in the no conversion group had undergone ECV; no patients in the conversion group experienced AF recurrence by Day 5 (0% required ECV; p<0.001).

Conclusions

Conversion of recent onset AF to SR with inhaled flecainide was associated with a reduction in symptoms, normalization of heart rate, rapid hospital discharge and avoidance of ECV during a 5-day follow-up period.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): InCarda Therapeutics

Predictors of successful cardioversion of recent-onset atrial fibrillation to sinus rhythm with orally inhaled flecainide

Background

Height, weight, and body mass index (BMI) are well established risk factors for atrial fibrillation (AF) but whether they are also predictors of successful pharmacological cardioversion of AF is unknown. Data from the open-label INSTANT study of flecainide acetate oral inhalation solution (FlecIH) for acute cardioversion of recent-onset symptomatic AF were examined to determine if these anthropometric measures are predictors of successful cardioversion of AF to sinus rhythm (SR) with FlecIH.

Methods

Logistic regression was performed on a broad array of patient and disease characteristics to identify predictors of cardioversion success at 90 minutes post-dose, and potential interactions were examined by boundary restriction analysis. Data are presented for patients receiving 120 mg FlecIH.

Results

Data from 81 patients (32.1% female) with a mean age of 59.8 years (range: 26.0, 84.0) were included in the analysis. This cohort had a mean weight of 87 kg (range: 57, 150), a mean height of 180 cm (range: 156, 199), and a mean BMI of 26.8 kg/m2 (range: 17.2, 37.9). A logistic regression model identified height, weight, and BMI as significant predictors of cardioversion success (p<0.01) and a boundary restriction analysis revealed a negative correlation between BMI and conversion rate across the entire dataset (see Figure 1). Clinically significant conversion rates were observed for patients with BMI values that were considered normal (BMI <25 kg/m2 = 53%; 95% CI: 36, 70), overweight (BMI ≥25 and <30 kg/m2 = 47%; 95% CI: 29, 64), and obese (BMI ≥30 and <35 kg/m2 = 43%; 95% CI: 17, 69); however, none of the severely obese patients (BMI ≥35 mg/m2) had their AF successfully converted to sinus rhythm (see Figure 2).

Conclusions

Successful cardioversion of recent onset AF with 120 mg FlecIH was observed in normal, overweight, and obese patients with BMI values <35 kg/m2; however, conversion rate decreases with increasing BMI. Further evaluation of FlecIH dosing in severely obese patients is warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): InCarda Therapeutics

Lessons learned in the Apple Heart Study and implications for the data management of future digital clinical trials

The digital clinical trial is fast emerging as a pragmatic trial that can improve a trial's design including recruitment and retention, data collection and analytics. To that end, digital platforms such as electronic health records or wearable technologies that enable passive data collection can be leveraged, alleviating burden from the participant and study coordinator. However, there are challenges. For example, many of these data sources not originally intended for research may be noisier than traditionally obtained measures. Further, the secure flow of passively collected data and their integration for analysis is non-trivial. The Apple Heart Study was a prospective, single-arm, site-less digital trial designed to evaluate the ability of an app to detect atrial fibrillation. The study was designed with pragmatic features, such as an app for enrollment, a wearable device (the Apple Watch) for data collection, and electronic surveys for participant-reported outcomes that enabled a high volume of patient enrollment and accompanying data. These elements led to challenges including identifying the number of unique participants, maintaining participant-level linkage of multiple complex data streams, and participant adherence and engagement. Novel solutions were derived that inform future designs with an emphasis on data management. We build upon the excellent framework of the Clinical Trials Transformation Initiative to provide a comprehensive set of guidelines for data management of the digital clinical trial that include an increased role of collaborative data scientists in the design and conduct of the modern digital trial.

Efficacy and safety of dronedarone versus placebo in patients with atrial fibrillation stratified according to renal function: Post hoc analyses of the EURIDIS-ADONIS trials

BACKGROUND

The use of antiarrhythmic drugs (AADs) in patients with chronic kidney disease (CKD) is complex because impaired renal clearance can cause increased drug levels, and risk of intolerance or adverse events. Due to the propensity for CKD to occur alongside atrial fibrillation/atrial flutter (AF/AFL), it is essential that AAD safety and efficacy are assessed for patients with CKD.

HYPOTHESIS

Dronedarone, an approved AAD, may present a suitable therapeutic option for patients with AF/AFL and concomitant CKD.

METHODS

EURIDIS-ADONIS (EURIDIS, NCT00259428; ADONIS, NCT00259376) were identically designed, multicenter, double-blind, parallel-group trials investigating AF/AFL control with dronedarone 400 mg twice daily versus placebo (randomized 2:1). In this post hoc analysis, the primary endpoint was time to first AF/AFL. Patients were stratified according to renal function using the CKD-Epidemiology Collaboration equation and divided into estimated glomerular filtration rate (eGFR) subgroups of 30-44, 45-59, 60-89, and ≥90 ml/min. Time-to-events between treatment groups were compared using log-rank testing and Cox regression.

RESULTS

At baseline, most (86%) patients demonstrated a mild or mild-to-moderate eGFR decrease. Median time to first AF/AFL recurrence was significantly longer with dronedarone versus placebo for all eGFR subgroups except the 30 to 44 ml/min group, where the trend was similar but statistical power may have been limited by the small population. eGFR stratification had no significant effect on serious adverse events, deaths, or treatment discontinuations.

CONCLUSIONS

This analysis suggests that dronedarone could be an effective therapeutic option for AF with an acceptable safety profile in patients with impaired renal function.

Cardiovascular benefits outweigh risks in patients with atrial fibrillation in REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial)

Background/Introduction

REDUCE-IT, a multinational, double-blind trial, randomized 8179 statin-treated patients with controlled low density lipoprotein cholesterol, elevated triglycerides, and cardiovascular (CV) risk, to icosapent ethyl (IPE) 4 grams/day or placebo. IPE reduced the primary (CV death, myocardial infarction [MI], stroke, coronary revascularization, hospitalization for unstable angina) and key secondary (CV death, MI, stroke) endpoints 25% and 26%, respectively (each p<0.0001), and individual components including stroke (28%), MI (31%), cardiac arrest (48%), and sudden cardiac death (31%) (all p≤0.01). With IPE, bleeding was greater (11.8% vs 9.9%; p=0.006), serious bleeding trended higher (2.7% vs 2.1%; p=0.06), and atrial fibrillation/flutter (AF/F) hospitalization endpoints increased (3.1% vs 2.1%; p=0.004).

Purpose

To evaluate the effects of IPE on the risk of CV events and safety measures in patients by either history of AF/F or in-study occurrence of positively adjudicated AF/F hospitalization.

Methods

Conduct post hoc efficacy and safety subgroup analyses of patients with or without either baseline history of AF/F or in-study adjudicated AF/F hospitalization, including hospitalization for ≥24 hours; AF/F not meeting endpoint criteria were reported as adverse events.

Results

Patients with (n=751; 9.2%) AF/F history at baseline (vs without; n=7428; 90.8%) (Figure 1), or those with (n=211; 2.6%) positively adjudicated in-study AF/F hospitalization endpoints (vs without; n=7968; 97.4%) (Figure 2), had higher event rates of primary, key secondary, and fatal or nonfatal stroke endpoints, but relative risk reductions with IPE were not significantly different (all interaction p-values [pint]=ns). Similar reductions were observed with IPE across the prespecified endpoint testing hierarchy in patients with or without AF/F history or in-study hospitalization endpoints. Patients with baseline AF/F history had similar relative risk for in-study occurrence of AF/F hospitalization with IPE versus placebo (pint=0.21) but had greater absolute risk (12.5% vs 6.3%, IPE vs placebo) vs patients without baseline AF/F history (2.2% vs 1.6%, IPE vs placebo); i.e., recurrent AF/F in those with a prior history of AF/F was more prevalent than de novo AF/F. Serious bleeding trended higher regardless of AF/F history or in-study AF/F hospitalization endpoints (all pint=ns); absolute risk of serious bleeding was greater in patients with AF/F history at baseline (7.3% vs 6.0%) vs those without a baseline history of AF/F (2.3% vs 1.7%), and serious bleeding also trended higher in patients with in-study AF/F hospitalization (8.7% vs 6.0%) vs without (2.5% vs 2.0%) [all IPE vs placebo].

Conclusion

REDUCE-IT patients with AF/F history or in-study AF/F hospitalization endpoints had greater CV risk, but similar relative risk reduction in primary, key secondary, and fatal or nonfatal stroke endpoints with IPE.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amarin Pharma, Inc.

Arrhythmias Other Than Atrial Fibrillation in Those With an Irregular Pulse Detected With a Smartwatch: Findings From the Apple Heart Study

[Figure: see text].

Reexamination of the Embolic Stroke of Undetermined Source Concept

Occult atrial fibrillation (AF) is a leading cause of stroke of unclear cause. The optimal approach to secondary stroke prevention for these patients remains elusive. The term embolic stroke of undetermined source (ESUS) was coined to describe ischemic strokes in which the radiographic features demonstrate territorial infarcts resembling those seen in patients with confirmed sources of embolism but without a clear source of embolism detected. It was assumed that patients with ESUS had a high rate of occult AF and would benefit from treatment with direct oral anticoagulants, which are at least as effective as vitamin K antagonists for secondary stroke prevention in patients with AF, but with a much lower risk of intracerebral hemorrhage. Two recent large randomized trials failed to show superiority of direct oral anticoagulants over aspirin in ESUS patients. These findings prompt a reexamination of the ESUS concept, with the goal of improving specificity for detecting patients with a cardioembolic cause. Based on the negative trial results, there is renewed interest in the role of long-term cardiac monitoring for AF in patients who fit the current ESUS definition, as well as the clinical implication of detecting AF. Ongoing trials are exploring these questions. Current ESUS definitions do not accurately detect the patients who should be prescribed direct oral anticoagulants, potentially because occult AF is less common than expected in these patients and/or anticoagulants may be less beneficial in patients with ESUS but no AF than they are for patients with stroke with established AF. More specific criteria to identify patients who may be at higher risk for occult AF and reduce their risk of subsequent stroke have been developed and are being tested in ongoing clinical trials.

Efficacy and safety of dronedarone vs placebo in patients with atrial fibrillation or atrial flutter across a spectrum of renal function: post hoc analyses of the EURIDIS-ADONIS trials

Background/Introduction

The use of antiarrhythmic drugs in patients with chronic kidney disease (CKD) is complex because impaired renal clearance can cause increased drug levels, and risk of intolerance or adverse events. Since CKD commonly co-occurs with atrial fibrillation/atrial flutter (AF/AFL), it is important to establish efficacy and safety for such drugs when used in AF/AFL patients with CKD.

Purpose

To evaluate the efficacy and safety of dronedarone in patients with AF or AFL across different levels of renal function.

Methods

This post hoc analysis evaluated pooled data from two multicentre, double-blind, randomised (2:1) trials of rhythm control with dronedarone 400 mg twice daily vs placebo. Primary endpoint was time to first recurrence of AF or AFL. Renal function (estimated glomerular filtration rate [eGFR]) was assessed with the CKD-Epidemiology Collaboration equation. Patients were grouped by eGFR strata. Log-rank testing and Cox regression were used to compare time to events between treatment groups.

Results

Most (85%) patients had mild or mild-to-moderate decrease in eGFR (Table 1). Median time to first AF recurrence was significantly longer in the dronedarone vs placebo group for all eGFR subgroups except the 30–44 mL/min group (Figure 1), where the trend was consistent; however, the small population size may have precluded meaningful analyses in this subgroup. Serious adverse events, deaths, and treatment discontinuations did not differ notably between each group irrespective of eGFR strata.

Conclusions

This analysis confirms the efficacy and safety of dronedarone in patients with AF across a wide spectrum of renal function.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Sanofi

Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation

BACKGROUND

Optical sensors on wearable devices can detect irregular pulses. The ability of a smartwatch application (app) to identify atrial fibrillation during typical use is unknown.

METHODS

Participants without atrial fibrillation (as reported by the participants themselves) used a smartphone (Apple iPhone) app to consent to monitoring. If a smartwatch-based irregular pulse notification algorithm identified possible atrial fibrillation, a telemedicine visit was initiated and an electrocardiography (ECG) patch was mailed to the participant, to be worn for up to 7 days. Surveys were administered 90 days after notification of the irregular pulse and at the end of the study. The main objectives were to estimate the proportion of notified participants with atrial fibrillation shown on an ECG patch and the positive predictive value of irregular pulse intervals with a targeted confidence interval width of 0.10.

RESULTS

We recruited 419,297 participants over 8 months. Over a median of 117 days of monitoring, 2161 participants (0.52%) received notifications of irregular pulse. Among the 450 participants who returned ECG patches containing data that could be analyzed - which had been applied, on average, 13 days after notification - atrial fibrillation was present in 34% (97.5% confidence interval [CI], 29 to 39) overall and in 35% (97.5% CI, 27 to 43) of participants 65 years of age or older. Among participants who were notified of an irregular pulse, the positive predictive value was 0.84 (95% CI, 0.76 to 0.92) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular pulse notification and 0.71 (97.5% CI, 0.69 to 0.74) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular tachogram. Of 1376 notified participants who returned a 90-day survey, 57% contacted health care providers outside the study. There were no reports of serious app-related adverse events.

CONCLUSIONS

The probability of receiving an irregular pulse notification was low. Among participants who received notification of an irregular pulse, 34% had atrial fibrillation on subsequent ECG patch readings and 84% of notifications were concordant with atrial fibrillation. This siteless (no on-site visits were required for the participants), pragmatic study design provides a foundation for large-scale pragmatic studies in which outcomes or adherence can be reliably assessed with user-owned devices. (Funded by Apple; Apple Heart Study ClinicalTrials.gov number, NCT03335800.).

Rationale and design of a large-scale, app-based study to identify cardiac arrhythmias using a smartwatch: The Apple Heart Study

Background

Smartwatch and fitness band wearable consumer electronics can passively measure pulse rate from the wrist using photoplethysmography (PPG). Identification of pulse irregularity or variability from these data has the potential to identify atrial fibrillation or atrial flutter (AF, collectively). The rapidly expanding consumer base of these devices allows for detection of undiagnosed AF at scale.

Methods

The Apple Heart Study is a prospective, single arm pragmatic study that has enrolled 419,093 participants (NCT03335800). The primary objective is to measure the proportion of participants with an irregular pulse detected by the Apple Watch (Apple Inc, Cupertino, CA) with AF on subsequent ambulatory ECG patch monitoring. The secondary objectives are to: 1) characterize the concordance of pulse irregularity notification episodes from the Apple Watch with simultaneously recorded ambulatory ECGs; 2) estimate the rate of initial contact with a health care provider within 3 months after notification of pulse irregularity. The study is conducted virtually, with screening, consent and data collection performed electronically from within an accompanying smartphone app. Study visits are performed by telehealth study physicians via video chat through the app, and ambulatory ECG patches are mailed to the participants.

Conclusions

The results of this trial will provide initial evidence for the ability of a smartwatch algorithm to identify pulse irregularity and variability which may reflect previously unknown AF. The Apple Heart Study will help provide a foundation for how wearable technology can inform the clinical approach to AF identification and screening. (Am Heart J 2019;207:66–75.)

The Second Annual Think Tank on Prevention of Sudden Cardiac Death in the Young: Developing a rational, reliable, and sustainable national health care resource. A report from the Cardiac Safety Research Consortium

Sudden cardiac death in the young (SCDY) spans gender, race, ethnicity, and socioeconomic class. The loss of any pediatric patient is a matter of national and international public health concern, and focused efforts should be aimed at preventing these burdensome tragedies. Prepared by members of the Cardiac Safety Research Consortium, this White Paper summarizes and reports the dialogue at the second Think Tank related to the issues and the proposed solutions for the development of a national resource for screening and prevention of SCDY. This Think Tank, sponsored by the Cardiac Safety Research Consortium and the United States Food and Drug Administration, convened on February 18, 2016, in Miami, FL, to identify and resolve the barriers that prevent early identification of patients at risk for SCDY. All potential stakeholders including national and international experts from industry, medicine, academics, engineering, and community advocacy leaders had an opportunity to share ideas and collaborate.

Pharmacological Therapy for Rate and Rhythm Control for Atrial Fibrillation in 2017

In spite of the emergence of non-pharmacological approaches, medical therapy remains the primary modality of treatment for most patients with atrial fibrillation (AF). This review will look at evidence for rate and rhythm control approaches, and at factors that would help in choosing the appropriate treatment strategy for individual patients.

Cardiovascular Safety of the Selective μ-Opioid Receptor Antagonist Naloxegol: A Novel Therapy for Opioid-Induced Constipation

Background:

Naloxegol is a novel selective, peripherally acting μ-opioid receptor antagonist for treating opioid-induced constipation (OIC) in patients with chronic pain syndromes. We analyzed the cardiovascular (CV) safety of naloxegol based on data from its development program prior to approval by the US Food and Drug Administration in 2015.

Methods:

Comprehensive CV safety analyses were performed in 4 clinical studies of naloxegol (12.5 and/or 25 mg) in patients with noncancer pain and OIC: two 12-week, double-blind, randomized studies; a 12-week, double-blind, extension study; and a 52-week, randomized, open-label study versus usual care. Evaluations of baseline CV risk were obtained from medical histories and clinical findings at the time of study initiation.

Results:

Across the 4 studies (N = 2135), 68% of patients had ≥1 CV risk factor and 41% had a history of CV disease, diabetes, or ≥2 other CV risk factors. There were no increases in blood pressure, heart rate, or the rate-pressure product with naloxegol versus placebo. The rates of major adverse cardiovascular events (MACE) per 100 patient-years of exposure were 1.13 (95% confidence interval [CI], 0.31-2.89) for placebo/usual care and 0.75 (95% CI, 0.24-1.75) for naloxegol. The relative risk of MACE for all doses of naloxegol versus placebo was 0.67 (95% CI, 0.14-3.36).

Conclusion:

These data demonstrate that naloxegol has a CV safety profile comparable to placebo/usual care in patients with OIC. Although the observed number of events was low, the data show no CV signal in patients with OIC treated with naloxegol.

Abstract 127: Differences in Care Patterns, Health Status, and Outcomes of Atrial Fibrillation in Patients With and Without Diabetes: Findings From the ORBIT-AF Registry

Objective: Diabetes is a common among patients with atrial fibrillation (AF). However, little is known on the impact of diabetes on symptoms, health status, care and outcomes among AF patients. We assessed whether symptoms, health status, care and outcomes differ between AF patients with and without diabetes.

Methods: This observational cohort study included 9,749 patients with AF from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation registry, a prospective, nationwide, multicenter outpatient registry of patients with incident and prevalent AF enrolled at 174 sites between June 2010 and August 2011. The outcomes were symptoms, health status, and AF treatment, as well as 2-year risks of death, readmission, thrombomebolic events, heart failure (HF) and AF progression.

Results: Among AF patients; those with diabetes (29.5%) were younger and more likely to have hypertension, chronic kidney disease, HF, coronary heart disease, and stroke. Patients with diabetes had a lower Atrial Fibrillation Effects on Quality of Life score (80.6 [IQR: 62.5 - 92.6] vs. 82.4 [IQR: 67.6 -93.5]; P = 0.025), but a higher CHA 2 DS 2 -VASc score (5 [IQR: 4 - 6] vs. 4 [2 - 5]; P <0.0001) and were more likely to receive anticoagulation ( P <0.001). Diabetes was associated with higher mortality, with a greater overall (adjusted hazard ratio [aHR]: 1.63 [95% CI: 1.04-2.56] for age<70 vs. 1.25 [1.09-1.44] for age ≥70) and cardiovascular (2.20 [1.22-3.98] for age<70 vs. 1.24 [1.02-1.51] for age ≥70) mortality risks before age 70 years. Diabetes conferred a higher risk of non-cardiovascular (CV) death (1.29 [1.06-1.56]), sudden cardiac death (1.53 [1.04-2.26]), hospitalization (1.15 [1.09-1.22]), CV hospitalization (1.13 [1.05-1.22]) and non-CV and non-bleeding-related hospitalization (1.19 [1.10-1.30]); but no increase in risks of thromboembolic events, bleeding related hospitalization, new-onset HF, and AF progression. The use of oral anticoagulants (OAC) modifies the relation of diabetes and all-cause hospitalization, with a higher risk among those on OAC (1.21 [1.12-1.29]).

Conclusions: Among patients with AF, diabetes was associated with worse AF symptoms and lower quality of life, as well an increased risk of death and hospitalizations, but not with the risk of thromboembolic or bleeding events.

Triple vs Dual Antithrombotic Therapy in Patients with Atrial Fibrillation and Coronary Artery Disease

BACKGROUND

The role of triple antithrombotic therapy vs dual antithrombotic therapy in patients with both atrial fibrillation and coronary artery disease remains unclear. This study explores the differences in treatment practices and outcomes between triple antithrombotic therapy and dual antithrombotic therapy in patients with atrial fibrillation and coronary artery disease.

METHODS

Using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (n = 10,135), we analyzed outcomes in patients with coronary artery disease (n = 1827) according to treatment with triple antithrombotic therapy (defined as concurrent therapy with an oral anticoagulant, a thienopyridine, and aspirin) or dual antithrombotic therapy (comprising either an oral anticoagulant and one antiplatelet agent [OAC plus AA] or 2 antiplatelet drugs and no anticoagulant [DAP]).

RESULTS

The use of triple antithrombotic therapy, OAC plus AA, and DAP at baseline was 8.5% (n = 155), 80.4% (n = 1468), and 11.2% (n = 204), respectively. Among patients treated with OAC plus AA, aspirin was the most common antiplatelet agent used (90%), followed by clopidogrel (10%) and prasugrel (0.1%). The use of triple antithrombotic therapy was not affected by patient risk of either stroke or bleeding. Patients treated with triple antithrombotic therapy at baseline were hospitalized for all causes (including cardiovascular) more often than patients on OAC plus AA (adjusted hazard ratio 1.75; 95% confidence interval, 1.35-2.26; P <.0001) or DAP (hazard ratio 1.82; 95% confidence interval, 1.25-2.65; P = .0018). Rates of major bleeding or a combined cardiovascular outcome were not significantly different by treatment group.

CONCLUSIONS

Choice of antithrombotic therapy in patients with atrial fibrillation and coronary artery disease was not affected by patient stroke or bleeding risks. Triple antithrombotic therapy-treated patients were more likely to be hospitalized for all causes than those on OAC plus AA or on DAP.

The HARMONY Trial: Combined Ranolazine and Dronedarone in the Management of Paroxysmal Atrial Fibrillation: Mechanistic and Therapeutic Synergism

BACKGROUND

Atrial fibrillation (AF) requires arrhythmogenic changes in atrial ion channels/receptors and usually altered atrial structure. AF is commonly treated with antiarrhythmic drugs; the most effective block many ion channels/receptors. Modest efficacy, intolerance, and safety concerns limit current antiarrhythmic drugs. We hypothesized that combining agents with multiple anti-AF mechanisms at reduced individual drug doses might produce synergistic efficacy plus better tolerance/safety.

METHODS AND RESULTS

HARMONY tested midrange ranolazine (750 mg BID) combined with 2 reduced dronedarone doses (150 mg BID and 225 mg BID; chosen to reduce dronedarone's negative inotropic effect-see text below) over 12 weeks in 134 patients with paroxysmal AF and implanted pacemakers where AF burden (AFB) could be continuously assessed. Patients were randomized double-blind to placebo, ranolazine alone (750 mg BID), dronedarone alone (225 mg BID), or one of the combinations. Neither placebo nor either drugs alone significantly reduced AFB. Conversely, ranolazine 750 mg BID/dronedarone 225 mg BID reduced AFB by 59% versus placebo (P=0.008), whereas ranolazine 750 mg BID/dronedarone 150 mg BID reduced AFB by 43% (P=0.072). Both combinations were well tolerated.

CONCLUSIONS

HARMONY showed synergistic AFB reduction by moderate dose ranolazine plus reduced dose dronedarone, with good tolerance/safety, in the population enrolled.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; Unique identifier: NCT01522651.

Abstract 152: Persistence of Warfarin versus Dabigatran Therapy in Patients with Atrial Fibrillation: Results from the ORBIT AF Registry

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.

Cardiovascular Safety Outcome Trials: A meeting report from the Cardiac Safety Research Consortium

This White Paper provides a summary of presentations and discussions at a Cardiovascular Safety Outcome Trials Think Tank cosponsored by the Cardiac Safety Research Consortium, the US Food and Drug Administration, and the American College of Cardiology, held at American College of Cardiology's Heart House, Washington, DC, on February 19, 2014. Studies to assess cardiovascular (CV) risk of a new drug are sometimes requested by regulators to resolve ambiguous safety signals seen during its development or among other members of its class. Think Tank participants thought that important considerations in undertaking such studies were as follows: (1) plausibility-how likely it is that a possible signal indicating risk is real, based on strength of evidence, and/or whether a plausible mechanism of action for potential CV harm has been identified; (2) relevance-what relative and absolute CV risk would need to be excluded to determine that the drug had an acceptable benefit-to-risk balance for its use in the intended patient population; and (3) how plausibility and relevance influence the timing and approach to further safety assessment.

Lack of concordance between empirical scores and physician assessments of stroke and bleeding risk in atrial fibrillation: results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry

BACKGROUND

Physicians treating patients with atrial fibrillation (AF) must weigh the benefits of anticoagulation in preventing stroke versus the risk of bleeding. Although empirical models have been developed to predict such risks, the degree to which these coincide with clinicians' estimates is unclear.

METHODS AND RESULTS

We examined 10 094 AF patients enrolled in the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF) registry between June 2010 and August 2011. Empirical stroke and bleeding risks were assessed by using the congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and previous stroke or transient ischemic attack (CHADS2) and Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) scores, respectively. Separately, physicians were asked to categorize their patients' stroke and bleeding risks: low risk (<3%); intermediate risk (3%-6%); and high risk (>6%). Overall, 72% (n=7251) in ORBIT-AF had high-risk CHADS2 scores (≥2). However, only 16% were assessed as high stroke risk by physicians. Although 17% (n=1749) had high ATRIA bleeding risk (score ≥5), only 7% (n=719) were considered so by physicians. The associations between empirical and physician-estimated stroke and bleeding risks were low (weighted Kappa 0.1 and 0.11, respectively). Physicians weighed hypertension, heart failure, and diabetes mellitus less significantly than empirical models in estimating stroke risk; physicians weighted anemia and dialysis less significantly than empirical models when estimating bleeding risks. Anticoagulation use was highest among patients with high stroke risk, assessed by either empirical model or physician estimates. In contrast, physician and empirical estimates of bleeding had limited impact on treatment choice.

CONCLUSIONS

There is little agreement between provider-assessed risk and empirical scores in AF. These differences may explain, in part, the current divergence of anticoagulation treatment decisions from guideline recommendations.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01165710.

Provider specialty and atrial fibrillation treatment strategies in United States community practice: findings from the ORBIT-AF registry

Background

The prevalence of atrial fibrillation (AF) continues to increase; however, there are limited data describing the division of care among practitioners in the community and whether care differs depending on provider specialty.

Methods and Results

Using the Outcomes Registry for Better Informed Treatment of AF (ORBIT‐AF) Registry, we described patient characteristics and AF management strategies in ambulatory clinic practice settings, including electrophysiology (EP), general cardiology, and primary care. A total of 10 097 patients were included; of these, 1544 (15.3%) were cared for by an EP provider, 6584 (65.2%) by a cardiology provider, and 1969 (19.5%) by an internal medicine/primary care provider. Compared with those patients who were cared for by cardiologists or internal medicine/primary care providers, patients cared for by EP providers were younger (median age, 73 years [interquartile range, IQR, 64, 80 years, Q1, Q3] versus 75 years [IQR, 67, 82 years] for cardiology and versus 76 years [IQR, 68, 82 years] for primary care). Compared with cardiology and internal medicine/primary care providers, EP providers used rhythm control (versus rate control) management more often (44.2% versus 29.7% and 28.8%, respectively, P<0.0001; adjusted odds ratio [OR] EP versus cardiology, 1.66 [95% confidence interval, CI, 1.05 to 2.61]; adjusted OR for internal medicine/primary care versus cardiology, 0.91 [95% CI, 0.65 to 1.26]). Use of oral anticoagulant therapy was high across all providers, although it was higher for cardiology and EP providers (overall, 76.1%; P=0.02 for difference between groups).

Conclusions

Our data demonstrate important differences between provider specialties, the demographics of the AF patient population treated, and treatment strategies—particularly for rhythm control and anticoagulation therapy.

Use and associated risks of concomitant aspirin therapy with oral anticoagulation in patients with atrial fibrillation: insights from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) Registry

BACKGROUND

The role of concomitant aspirin (ASA) therapy in patients with atrial fibrillation (AF) receiving oral anticoagulation (OAC) is unclear. We assessed concomitant ASA use and its association with clinical outcomes among AF patients treated with OAC.

METHODS AND RESULTS

The Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry enrolled 10 126 AF patients from 176 US practices from June 2010 through August 2011. The study population was limited to those on OAC (n=7347). Hierarchical multivariable logistic regression models were used to assess factors associated with concomitant ASA therapy. Primary outcomes were 6-month bleeding, hospitalization, ischemic events, and mortality. Overall, 35% of AF patients (n=2543) on OAC also received ASA (OAC+ASA). Patients receiving OAC+ASA were more likely to be male (66% versus 53%; P<0.0001) and had more comorbid illness than those on OAC alone. More than one third of patients (39%) receiving OAC+ASA did not have a history of atherosclerotic disease, yet 17% had elevated Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) bleeding risk scores (≥5). Major bleeding (adjusted hazard ratio, 1.53; 95% confidence interval, 1.20-1.96) and bleeding hospitalizations (adjusted hazard ratio, 1.52; 95% confidence interval, 1.17-1.97) were significantly higher in those on OAC+ASA compared with those on OAC alone. Rates of ischemic events were low.

CONCLUSIONS

Patients with AF receiving OAC are often treated with concomitant ASA, even when they do not have cardiovascular disease. Use of OAC+ASA was associated with significantly increased risk for bleeding, emphasizing the need to carefully determine if and when the benefits of concomitant ASA outweigh the risks in AF patients already on OAC.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. UNIQUE IDENTIFIER: NCT01165710.

Predictors of progression of recently diagnosed atrial fibrillation in REgistry on Cardiac Rhythm DisORDers Assessing the Control of Atrial Fibrillation (RecordAF)-United States cohort

The progression of atrial fibrillation (AF) to a more sustained form is associated with increased symptoms and morbidity. The aims of the REgistry on Cardiac Rhythm DisORDers Assessing the Control of Atrial Fibrillation (RecordAF)-United States (US) cohort study were to identify the risk factors of AF progression and the effects of management approaches. RecordAF is the first worldwide, 1-year observational study of the treatment of community-based patients with recent-onset AF. We assessed AF progression at 12 months in the US cohort. AF progression was defined as a change of AF to a more sustained form (either paroxysmal becoming persistent or permanent, or persistent becoming permanent). The US cohort included 955 patients, with mean age of 68.9 years; 56.8% were men and 88.8% were white. At entry, 59.6% of patients were selected for rate-control and 40.4% for rhythm-control therapy. At 12 months, the management strategy was unchanged for 68.2% of the patients in the rate- and 77.7% of the patients in the rhythm-control groups. Overall, AF progression had occurred in 18.6% of patients at 12 months. The progression rate was significantly greater in the rate-control (27.6%) than in the rhythm-control (5.8%) group (p <0.001). Progression to permanent AF occurred in 16.4% of patients. In addition to a rate-control strategy, older age, AF rhythm at entry, persistent AF at baseline, and a history of stroke or transient ischemic attack independently predicted AF progression. Rate control was associated with AF progression, with a propensity score adjusted odds ratio of 2.67 (p <0.001). In conclusion, rate control was the preferred treatment of recent-onset AF in the US but was associated with more AF progression than rhythm control.

Abstract 303: Adoption of the Novel Oral Anticoagulant Dabigatran in Patients with Atrial Fibrillation Receiving Warfarin in Community Practice: Findings from ORBIT AF

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.

Abstract 10: Contraindications to Oral Anticoagulation in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF)

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.

Abstract 79: Reasons for Warfarin Discontinuation in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF)

Background. Warfarin reduces the risk of thromboembolic events associated with atrial fibrillation (AF), but therapeutic persistence is suboptimal. Few studies have investigated the reasons for warfarin discontinuation in community practice.

Methods. We used data from ORBIT-AF, the nation’s largest AF database, to examine patterns of warfarin discontinuation over a one-year period. Patients transitioned to non-warfarin oral anticoagulation therapy were excluded. We compared patient and provider characteristics between individuals who discontinued warfarin and those who persisted.

Results. From June 2010 to August 2011, 10,126 AF patients 18 years or older were enrolled at 176 ORBIT-AF practices. Of these, 6,559 (64.8%) were taking warfarin at baseline and have follow-up data; 514 (7.8%) of these switched to dabigatran and were excluded from the analysis. Additionally, two patients without follow-up warfarin data were excluded from the analysis. Over one year, 587 patients (9.7%) discontinued warfarin therapy. Compared to persistent users, patients who discontinued warfarin were younger, less likely to be white, had lower stroke risk (CHADS 2 <2), were more likely to follow a rhythm control strategy, and were less likely to be managed in an anticoagulation clinic (Table 1). The most commonly reported reasons for warfarin discontinuation were physician preference (31.0%), other (18.7%), patient refusal/preference (13.6%), bleeding event (13.3%), frequent falls/frailty (7.3%), high bleeding risk (6.6%), and patient inability to adhere to/monitor therapy (2.9%).

Conclusions. Discontinuation of warfarin is common among patients with atrial fibrillation. Patient and physician preference are major contributors to persistence on warfarin therapy.