Archive

Archive for the ‘atrial fibrillation’ Category

High Atrial Rate Episodes and Thromboembolic Risk in a Japanese Population

Kawakami et al report on the relationship between high atrial rate episodes (defined as episodes of atrial tachyarrhythmias of more than 6 minutes on atrial monitoring) in Japanese patients with pacemakers capable of continuous atrial monitoring.

Abstract

Abstract

Objective

The clinical significance of atrial high-rate
episodes (AHREs) detected by cardiac devices among
patients with implantable pacemakers has recently
emerged. However, the relationship between AHREs and
ischaemic stroke and systemic embolism (SE) is not well
understood in the Japanese population.

Methods

This study included 343 patients with
pacemakers capable of continuous atrial rhythm monitoring (167 males; mean age, 80±7 years). Atrial tachyarrhythmia detection was programmed to the nominal setting of each device, and AHRE was defined as any episode of sustained atrial tachyarrhythmia lasting for more than 6 min. Thromboembolic risk was defined based on the CHADS2 score.

Results

During the follow-up period (52±30 months),
165 (48%) patients had at least one episode of AHREs,
and 19 (6%) patients experienced stroke/SE. Among
patients who experienced stroke/SE, 14 had AHREs
before the stroke/SE. AHREs were significantly associated with stroke/SE (HR 2.87; 95% CI 1.10 to 8.90; p=0.03). Subgroup analysis conducted to investigate the impact of the CHADS2 score severity on stroke/SE revealed that AHREs were not associated with stroke/SE in patients with low or intermediate thromboembolic
risk (CHADS2 score 0–2; n=217). In contrast, among
patients with high thromboembolic risk (CHADS2
score>2; n=126), there was a significant association
between AHREs and the incidence of stroke/SE (HR 3.73;
95% CI 1.06 to 13.1; p=0.04).

Conclusion

AHREs detected by pacemaker were associated with ischaemic stroke/SE in the Japanese population. However, this association was observed only in the high thromboembolic risk group.

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AF Screening

Freedman et al present a white paper from the AF-SCREEN International Collaborative. This important paper collates evidence for AF screening and provides insights into the risk of asymptomatic atrial fibrillation and the temporal relationship between AF and ischemic stroke.

 

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Alcohol and Atrial Fibrillation

Voskoboinik et al review the relationship between alcohol and atrial fibrillation. This is an interesting and useful paper.

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AHA 2016: Initial Look

Journal Club 22 October 2014

Paper

Increased Mortality Associated With Digoxin in Contemporary Patients With Atrial Fibrillation Findings From the TREAT-AF Study

Presenter

AB

Summary

BACKGROUND

Despite endorsement of digoxin in clinical practice guidelines, there exist limited data on its safety in
atrial fibrillation/flutter (AF).

OBJECTIVES

The goal of this study was to evaluate the association of digoxin with mortality in AF.
METHODS Using complete data of the TREAT-AF (The Retrospective Evaluation and Assessment of Therapies in AF)
study from the U.S. Department of Veterans Affairs (VA) healthcare system, we identified patients with newly diagnosed,
nonvalvular AF seen within 90 days in an outpatient setting between VA fiscal years 2004 and 2008. We used multivariate
and propensity-matched Cox proportional hazards to evaluate the association of digoxin use with death. Residual
confounding was assessed by sensitivity analysis.

RESULTS

Of 122,465 patients with 353,168 person-years of follow-up (age 72.1 10.3 years, 98.4% male), 28,679
(23.4%) patients received digoxin. Cumulative mortality rates were higher for digoxin-treated patients than for untreated
patients (95 vs. 67 per 1,000 person-years; p < 0.001). Digoxin use was independently associated with mortality after
multivariate adjustment (hazard ratio [HR]: 1.26, 95% confidence interval [CI]: 1.23 to 1.29, p < 0.001) and propensity
matching (HR: 1.21, 95% CI: 1.17 to 1.25, p < 0.001), even after adjustment for drug adherence. The risk of death was not
modified by age, sex, heart failure, kidney function, or concomitant use of beta-blockers, amiodarone, or warfarin.

CONCLUSIONS

Digoxin was associated with increased risk of death in patients with newly diagnosed AF, independent
of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge
current cardiovascular society recommendations on use of digoxin in AF.

Supplementary Material

AFFIRM study
AFFIRM subset
AFFIRM subset editorial

Journal Club 23 April 2014

Paper

A Randomized Trial to Assess Catheter Ablation Versus Rate Control in the Management of Persistent Atrial Fibrillation in Heart Failure

Presenter

PM

Summary

Objectives

This study sought to compare catheter ablation with rate control for persistent atrial fibrillation (AF) in heart fail- ure (HF).
Background The optimal therapy for AF in HF is unclear. Drug-based rhythm control has not proved clinically beneficial. Cath-
eter ablation improves cardiac function in patients with HF, but impact on physiological performance has not been formally evaluated in a randomized trial.

Methods

In a randomized, open-label, blinded-endpoint clinical trial, adults with symptomatic HF, radionuclide left ventric- ular ejection fraction (EF) Յ35%, and persistent AF were assigned to undergo catheter ablation or rate control. Primary outcome was 12-month change in peak oxygen consumption. Secondary endpoints were quality of life, B-type natriuretic peptide, 6-min walk distance, and EF. Results were analyzed by intention-to-treat.

Results

Fifty-two patients (age 63 Ϯ 9 years, EF 24 Ϯ 8%) were randomized, 26 each to ablation and rate control. At 12 months, 88% of ablation patients maintained sinus rhythm (single-procedure success 68%). Under rate control, rate criteria were achieved in 96%. The primary endpoint, peak oxygen consumption, significantly increased in the ablation arm compared with rate control (difference ϩ3.07 ml/kg/min, 95% confidence interval: 0.56 to 5.59, p ϭ 0.018). The change was not evident at 3 months (ϩ0.79 ml/kg/min, 95% confidence interval: Ϫ1.01 to 2.60, p ϭ 0.38). Ablation improved Minnesota score (p ϭ 0.019) and B-type natriuretic peptide (p ϭ 0.045) and showed nonsignificant trends toward improved 6-min walk distance (p ϭ 0.095) and EF (p ϭ 0.055).

Conclusions

This first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF
shows significant benefit from ablation, a strategy that also improves symptoms and neurohormonal status. The ef- fects develop over 12 months, consistent with progressive amelioration of the HF syndrome.

Supplementary Material

The editorial is here.

European Practical Guide to New Oral Anticoagulants for Nonvalvular Atrial Fibrillation

The full European Society of Cardiology practical guideline for use of new (novel) oral anticoagulants in nonvalvular atrial fibrillation is available here.