Dingxin Qin

Gender differences in management and clinical outcomes of atrial fibrillation patients

BACKGROUND Prior research has identified gender differences in the epidemiology and clinical management of atrial fibrillation (AF). The primary aim of this study is to systematically analyze a cohort of AF men and women and evaluate their baseline demographics, treatment, and clinical outcomes by gender. METHODS We examined the records of 5976 (42% women) consecutive AF patients who were prescribed at least one anti-arrhythmic drug between 2006 and 2013. From this cohort, 4311 (72%) patients had anticoagulation data available and were included in the final analysis. Time to clinical events was assessed using survival analysis and adjusted for covariates using Cox regression. RESULTS Compared to men, women were older (73 years vs. 67 years, p<0.001), had higher CHADS2 scores (1.9 vs. 1.5, p<0.001), and fewer cardiac comorbidities. Compared to men, women were more often prescribed sotalol and less often dofetilide (p<0.001). Women were also less likely to be anticoagulated (76.8% vs. 82.5%, p<0.001). Over a mean follow-up of 40 months, women were more likely to die (HR 1.21, p=0.037) or to have an ischemic stroke (HR 1.35, p=0.058). Women also had higher rates of atrioventricular-nodal ablation (adjusted HR 2.11, p<0.001) and pacemaker implantation (adjusted HR 1.69, p<0.001) procedures, but lower rates of electrical cardioversions, AF ablations, and maze surgeries. CONCLUSIONS There are significant gender differences in baseline demographics and clinical outcomes of AF patients. Women have higher mortality and ischemic strokes and are less often prescribed anticoagulation therapy despite higher CHADS2 scores. These data have important clinical implications.

Comparative effectiveness of antiarrhythmic drugs for rhythm control of atrial fibrillation

INTRODUCTION Although there are many different antiarrhythmic drugs (AADs) approved for rhythm management of atrial fibrillation (AF), little comparative effectiveness data exist to guide drug selection. METHODS We followed 5952 consecutive AF patients who were prescribed amiodarone (N=2266), dronedarone (N=488), dofetilide (N=539), sotalol (N=1718), or class 1C agents (N=941) to the primary end point of AF recurrence. RESULTS Median follow-up time was 18.2 months (range 0.1-101.6 months). Patients who were prescribed amiodarone had the highest, while patients on class 1C agents had the lowest baseline CHA2DS2-VASc score, Charlson comorbidity index, and burden of comorbid illnesses including coronary artery disease, congestive heart failure, diabetes mellitus, hyperlipidemia, chronic obstructive lung disease, chronic kidney disease, or cancer (p<0.05 for all comparisons). After adjusting for baseline characteristics, using dronedarone as benchmark, amiodarone [hazard ratio (HR) 0.58, p<0.001], class 1C agents (HR 0.70, p<0.001), and sotalol (HR 0.79, p=0.008), but not dofetilide (HR 0.87, p=0.178) were associated with less AF recurrence. In addition, compared to dronedarone, amiodarone and class 1C agents were associated with lower rates of admissions for AF (HR 0.55, p<0.001 for amiodarone; HR 0.71, p=0.021 for class 1C agents) and all-cause mortality was lowest in patients treated with class 1C agents (HR 0.42, p=0.018). The risk of stroke was similar among all groups. CONCLUSION Compared with dronedarone, amiodarone, class 1C agents, and sotalol are more effective for rhythm control, while dofetilide had similar efficacy. These findings have important implications for clinical practice.

Risk of Stroke and Death in Atrial Fibrillation by Type of Anticoagulation: A Propensity‐Matched Analysis

We examined the effect of novel oral anticoagulants (NOACs) compared to warfarin on the risk of death or stroke in atrial fibrillation (AF) patients in every day clinical practice.

Patient Outcomes According to Adherence to Treatment Guidelines for Rhythm Control of Atrial Fibrillation

Background Although guidelines for antiarrhythmic drug therapy in atrial fibrillation (AF) were published in 2006, it remains uncertain whether adherence to these guidelines affects patient outcomes. Methods and Results We retrospectively evaluated the records of 5976 consecutive AF patients who were prescribed at least 1 antiarrhythmic drug between 2006 and 2013. Patients with 1 or more prescribed antiarrhythmic drugs that did not comply with guideline recommendations comprised the non–guideline‐directed group (=2920); the remainder constituted the guideline‐directed group (=3056). Time to events was assessed using the survival analysis method and adjusted for covariates using Cox regression. Rates of adherence to the guidelines increased significantly with a higher degree of prescriber specialization in arrhythmias (49%, 55%, and 60% for primary care physicians, general cardiologists, and cardiac electrophysiologists, respectively, P=0.001) for the first prescribed antiarrhythmic drug. Compared to the non–guideline‐directed group, the guideline‐directed group had higher rates of heart failure, but lower baseline CHADS2‐VASc scores (P<0.001) and lower rates of coronary artery disease, valvular disease, hypertension, hyperlipidemia, pulmonary disease, and renal insufficiency (P<0.05 for all). During 45±26 months follow‐up, the guideline‐directed group had a lower risk of AF recurrence (hazard ratio=0.86, 95% CI=0.80 to 0.93), fewer hospital admissions for AF (hazard ratio=0.87, 95% CI=0.79 to 0.97), and fewer procedures for recurrent AF, including electrical cardioversion, pacemaker implantation, and atrioventricular nodal ablation (P<0.01 for all). The mortality and stroke risks were similar between the groups. Conclusions Adherence to published guidelines in the antiarrhythmic management of AF is associated with improved patient outcomes.

Implantable Defibrillator Therapy in Cardiac Arrest Survivors With a Reversible Cause

Background: Current guidelines recommend implantable cardioverter-defibrillator (ICD) therapy in survivors of sudden cardiac arrest (SCA), except in those with completely reversible causes. We sought to examine the impact of ICD therapy on mortality in survivors of SCA associated with reversible causes. Methods and Results: We evaluated the records of 1433 patients managed at our institution between 2000 and 2012 who were discharged alive after SCA. A reversible and correctable cause was identified in 792 (55%) patients. Reversible SCA cause was defined as significant electrolyte or metabolic abnormality, evidence of acute myocardial infarction or ischemia, recent initiation of antiarrhythmic drug or illicit drug use, or other reversible circumstances. Of the 792 SCA survivors because of a reversible and correctable cause (age 61±15 years, 40% women), 207 (26%) patients received an ICD after their index SCA. During a mean follow-up of 3.8±3.1 years, 319 (40%) patients died. ICD implantation was highly associated with lower all-cause mortality (P<0.001) even after correcting for unbalanced baseline characteristics (P<0.001). In subgroup analyses, only patients whose SCA was not associated with myocardial infarction extracted benefit from ICD (P<0.001). Conclusions: In survivors of SCA because of a reversible and correctable cause, ICD therapy is associated with lower all-cause mortality except if the SCA was because of myocardial infarction. These data deserve further investigation in a prospective multicenter randomized controlled trial, as they may have important and immediate clinical implications.

Mortality risk of long-term amiodarone therapy for atrial fibrillation patients without structural heart disease.

BACKGROUND Amiodarone is often prescribed in the management of atrial fibrillation (AF) but is known to cause significant end-organ toxicities. In this study, we examined the impact of amiodarone on all-cause mortality in AF patients with structurally normal hearts. METHODS We performed a retrospective cohort analysis of all AF patients with structurally normal hearts who were prescribed antiarrhythmic drugs (AAD) for rhythm control of AF at our institution from 2006 to 2013 (n = 2,077). Baseline differences between the amiodarone (AMIO: n = 403) and other AADs (NON-AMIO: n = 1,674) groups were corrected for using propensity score matching. RESULTS Amiodarone use as first-line therapy decreased significantly with a higher degree of prescriber specialization in arrhythmia management (31%, 22%, and 9% for primary care physicians, general cardiologists and cardiac electrophysiologists, respectively, p < 0.001). After propensity score matching, baseline comorbidities were balanced between the AMIO and NON-AMIO groups. Over a median follow-up of 28.2 months (range 6.0-100.9 months), amiodarone was associated with increased all-cause (HR 2.41, p = 0.012) and non-cardiac (HR 3.55, p = 0.008) mortality, but not cardiac mortality. AF recurrence and cardiac hospitalizations were similar between the two study groups. CONCLUSIONS Amiodarone treatment of AF is associated with increased mortality in patients without structural heart disease and therefore should be avoided or only used as a second-line therapy, when other AF therapies fail. Adherence to guideline recommendations in the management of AF patients impacts clinical outcome.

ADHERENCE TO PUBLISHED GUIDELINES IN PRESCRIBING ANTI-ARRHYTHMIC MEDICATIONS AND ITS IMPACT ON CLINICAL OUTCOMES OF ATRIAL FIBRILLATION

Although guidelines for antiarrhythmic drug (AAD) therapy in atrial fibrillation (AF) were published in 2006, it remains uncertain whether adherence to these guidelines affects patient outcome. We evaluated the records of 5,976 AF patients who were prescribed at least one AAD between 2006 and 2013