Influence of the randomized trials, AFFIRM and RACE, on the management of atrial fibrillation in two University Medical Centers

Rhythm- or rate-control strategies according to 4S-AF characterization scheme and long-term outcomes in atrial fibrillation patients: the FAMo (Fibrillazione Atriale in Modena) cohort

The 4S-AF scheme [Stroke risk, Symptom severity, Severity of atrial fibrillation (AF) burden, Substrate severity] was recently proposed to characterize AF patients. In this post hoc analysis we evaluated the agreement between the therapeutic strategy (rate or rhythm control, respectively), as suggested by the 4S-AF scheme, and the actual strategy followed in a patients cohort. Outcomes of interest were as follows: all-cause death, a composite of all-cause death/any thromboembolism/acute coronary syndrome, and a composite of all-cause death, any thrombotic/ischemic event, and major bleeding (net clinical outcome). We enrolled 615 patients: 60.5% male, median age 74 [interquartile range (IQR) 67-80] years; median CHA₂DS₂VASc 4 and median HAS-BLED 2. The 4S-AF score would have suggested a rhythm-control strategy in 351 (57.1%) patients while a rate control in 264 (42.9%). The strategy adopted was concordant with the 4S-AF suggestions in 342 (55.6%) cases, and non-concordant in 273 (44.4%). After a median follow-up of 941 days (IQR 365-1282), 113 (18.4%) patients died, 158 (25.7%) had an event of the composite endpoint. On adjusted Cox regression analysis, when 4S-AF score suggested rate control, disagreement with that suggestion was not associated with a worse outcome. When 4S-AF indicated rhythm control, disagreement was associated with a higher risk of all-cause death (HR 7.59; 95% CI 1.65-35.01), and of the composite outcome (HR 2.69; 95% CI 1.19-6.06). The 4S-AF scheme is a useful tool to comprehensively evaluate AF patients and aid the decision-making process. Disagreement with the rhythm control suggestion of the 4S-AF scheme was associated with adverse clinical outcomes.

Gender Differences in Patients with Atrial Fibrillation Undergoing Electrical Cardioversion

BACKGROUND

Current recommendations on the rhythm control strategy for treatment of atrial fibrillation (AF) are more restrictive than a decade ago. Gender may play a role in decisions on the management of AF, including application of electrical cardioversion.

METHODS

We analyzed clinical characteristics by gender in patients participating in the observational survey about stable patients underlying cardioversion in Spain (CARDIOVERSE) study (n=915), a survey of the practice of electrical cardioversion in 67 Spanish hospitals. We compared these data with those from a previous survey of electrical cardioversion in Spain (REVERSE study) performed 8 years previously.

RESULTS

Patients undergoing electrical cardioversion were mainly men (76%). This finding was observed in all age groups, independently of symptoms. Men were younger (62±10 years vs. 69±9 years; p<0.001), more frequently asymptomatic and had a lower prevalence of hypertension and a lower stroke risk. Among asymptomatic patients, the predominance of men was especially evident in older age groups (<65 years, men 76%, women 24%; ≥65 years, men 92%, women 8% (p<0.001). Compared with the REVERSE study, we observed a decrease in the percentage of women among patients undergoing electrical cardioversion (37% REVERSE vs. 24% CARDIOVERSE; p<0.001), mainly in older than 65 years.

CONCLUSIONS

Our results support the hypothesis that gender is a determinant in decisions on the most appropriate strategy for managing AF. We observed a decrease in the percentage of women undergoing electrical cardioversion during the last decade, especially in older asymptomatic patients.

Trends in the pharmacologic management of atrial fibrillation: Data from the Veterans Affairs health system

BACKGROUND

Prescribing rate control medications with or without antiarrhythmic drugs is often the first course treatment for atrial fibrillation (AF). Clinical trial data suggest that antiarrhythmic drugs are only marginally effective and have multiple drawbacks, whereas rate control alone is sufficient for most patients with minimally symptomatic AF. This study investigates changes in the use of oral rate and rhythm control therapy for AF during fiscal years 2002 through 2011 in the US Veterans Affairs (VA) health system.

METHODS

Patients with new AF episodes were identified in Veterans Health Administration administrative data files, and receipt of oral rate- and rhythm-controlling drugs within 90 days of new AF episodes was determined for each patient.

RESULTS

The percentage of patients receiving an oral rate-controlling medication decreased from 74.9% in 2002 through 2003 to 70.9% in 2010 through 2011. The use of digoxin decreased by >50%, whereas the use of β-blockers metoprolol and carvedilol increased. The proportion of patients receiving any oral antiarrhythmic medication decreased from 13.5% in 2002 through 2003 to 11.6% in 2010 through 2011, and use of the most frequently prescribed oral antiarrhythmic, amiodarone, decreased by 17%.

CONCLUSIONS

Rate control remains the dominant strategy for treating new AF. The decrease in the use of oral antiarrhythmics may be due to lack of concrete data suggesting mortality and morbidity benefit as well as increasing use of the ablation approach.

BULLET POINTS

The proportion of patients with new AF episodes who were prescribed oral rate or rhythm control medications decreased modestly from 2002 through 2011. The use of digoxin decreased by >50%, and amiodarone decreased by 17%. Rate control remains the dominant strategy for treating new AF.

A new decline in hospitalization with atrial fibrillation among the elderly

BACKGROUND

Recent studies of atrial fibrillation within the United States showed an increase in the number and rate of hospitalization and death from 1979 to 1999. We tested the hypothesis that the trends in hospitalization and death with atrial fibrillation would be upward and similar from 1999 to 2009.

METHODS

We examined data for 1999-2009 from the US National Hospital Discharge Survey for diagnoses of atrial fibrillation (International Classification of Diseases, 9th Revision, Clinical Modification code 427.3) among up to 7 coded diagnoses and data from the National Vital Statistics System for deaths with atrial fibrillation (International Classification of Diseases 10th revision code I45). We computed all-listed diagnosis numbers and rates per 100,000 for discharges and deaths.

RESULTS

In 2009, the estimated number of all-listed diagnoses of atrial fibrillation in the United States was 2,643,000: 1,330,000 (50%) in women, 2,155,000 (82%) at ages 65+ years, and 467,000 (18%) first-listed diagnoses. At age 65+ years, the number increased from 2,049,000 in 1999 to 2,573,000 in 2005, and then decreased to 2,155,000 in 2009 (10% higher than 1999). The rate per 100,000 increased 17% from 5984 in 1999 to 6994 in 2005, and then decreased 22% to 5445 in 2009, 9% lower than 1999. The average annual percentage change was 3.12% from 1999 to 2005 compared with -5.00% from 2005 to 2009. Rates of death with atrial fibrillation increased 2% annually throughout the period.

CONCLUSIONS

In contrast to steadily increasing rates of death with atrial fibrillation, rates of diagnoses of atrial fibrillation at hospital discharge increased from 1999 to 2005, and then decreased slightly between 2005 and 2009. Further research is needed to assess explanations for these trends.

Trends in the use of electrical cardioversion for atrial fibrillation: influence of major trials and guidelines on clinical practice

BACKGROUND

The purpose of the present study was to assess the trends in the use of ECV following published studies that had compared rhythm and rate control strategies on atrial fibrillation (AF), and the recommendations included in the current clinical practice guidelines.

METHODS

The REVERCAT is a population-based assessment of the use of electrical cardioversion (ECV) in treating persistent AF in Catalonia (Spain). The initial survey was conducted in 2003 and the follow-up in 2010.

RESULTS

We observed a decrease of 9% in the absolute numbers of ECV performed (436 in 2003 vs. 397 in 2010). This is equivalent to 27% when considering population increases over this period. The patients treated with ECV in 2010 were younger, had a lower prevalence of previous embolism, a higher prevalence of diabetes, and increased body weight. Underlying heart disease factors indicated, in 2010, a higher proportion of NYHA ≥ II and left ventricular ejection fraction <30%. We observed a reduction in the number of ECV performed in 16 of the 27 (67%) participating hospitals. However, there was an increase of 14% in the number of procedures performed in tertiary hospitals, and was related to the increasing use of ECV as a bridge to AF ablation. Considering the initial number of patients treated with ECV, the rate of sinus rhythm at 3 months was almost unchanged (58% in 2003 vs. 57% in 2010; p=0.9) despite the greater use of biphasic energy in 2010 and a similar prescription of anti-arrhythmic drugs.

CONCLUSIONS

Although we observed a decrease in the number of ECVs performed over the 7 year period between the two studies, this technique remains a common option for treating patients with persistent AF. The change in the characteristics of candidate patients did not translate into better outcomes.

Trends in US hospitalization rates and rhythm control therapies following publication of the AFFIRM and RACE trials

INTRODUCTION

The impact of trials comparing rate versus rhythm control for AF on subsequent use of rhythm control therapies and hospitalizations at a national level has not been described.

METHODS AND RESULTS

We queried the Healthcare Cost & Utilization Project on the frequency of hospital admissions and performance of specific rhythm control procedures from 1998-2006. We analyzed trends in hospitalization for AF as principal diagnosis before and after the publication of key rate versus rhythm trials in 2002. We also reviewed the use of electrical cardioversion and catheter ablation as principal procedures during hospital admissions for any cause and for AF as principal diagnosis. We additionally appraised the overall outpatient utilization of antiarrhythmic drugs during this same time frame using IMS Health's National Prescription Audit.™ Admissions for AF as a principal diagnosis increased at 5%/year from 1998-2002. Following publication of the AFFIRM and RACE trials in 2002, admissions declined by 2%/year from 2002-2004, before rising again from 2004-2006. In-hospital electrical cardioversion followed a similar pattern. National prescription volumes for antiarrhythmic drugs grew at <1% per year from 2002 to 2006, with a marked decline in the use of class I-A agents, while catheter ablations during admissions for AF as the principal diagnosis increased at 30% per year.

CONCLUSION

The use of rhythm control therapies in the US declined significantly in the first few years after publication of AFFIRM and RACE. This trend reversed by 2005, at which time rapid growth in the use of catheter ablation for AF was observed.