Defining Clinically Important Difference in the Atrial Fibrillation Effect on Quality-of-Life Score.

Background The Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire has recently been validated to measure the impact of atrial fibrillation on quality of life, but a clinically important difference in AFEQT score has not been well defined. Methods and Results To determine the clinically important difference in overall AFEQT (score range= 0 [worst] to 100 [best]) and selected subscales, we analyzed data in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry, a United States-based outpatient atrial fibrillation registry. AFEQT was assessed at baseline and 1 year in a subset of 1347 ORBIT-AF patients from 80 US sites participating in ORBIT-AF from June 2010 to August 2011. The mean change method was used to relate changes in 1-year AFEQT scores to clinically important changes in the physician assessment of European Heart Rhythm Association functional status (1 class improvement and separately 1 class deterioration). Clinically important differences and 95% CI corresponding to either a 1 European Heart Rhythm Association class improvement or deterioration were 5.4 (3.6-7.2) and -4.2 (-6.9 to -1.5) AFEQT points, respectively. Similarly, clinically important difference values were seen for a 1 European Heart Rhythm Association class improvement for the AFEQT subscales Activities of Daily Living and Symptoms: 5.1 (2.5-7.6) and 7.1 (5.3-9.0) AFEQT points, respectively. Conclusions Based on the anchor of 1 European Heart Rhythm Association class change, changes in AFEQT score of + or -5 points are clinically important changes in patients' health. Clinical Trial Registration URL: https://clinicaltrials.gov . Unique identifier: NCT01165710.

Optimum Risk Assessment for Stroke in Atrial Fibrillation: Should We Hold the Status Quo or Consider Magnitude Synergism and Left Atrial Appendage Anatomy?

Thromboembolic stroke and systemic embolism are generally agreed to be the major morbidity/mortality concerns for patients with AF. However, the risk of thromboembolism is not the same for all AF patients. Both AF and comorbidities must interact synergistically to create the risk for thromboembolism. But, is the synergism dichotomous - AF present or absent, comorbid disorder present or absent - or does synergism have magnitude, depending on the number and severity of the associated disorders and the amount of time one is in AF? This review discusses the current risk-score contributors and options for assessing risk of thromboembolism in AF patients, and what their combined roles might be. Also covered is the consideration of left atrial appendage anatomy in this context.

Cardioversion for atrial fibrillation: treatment options and advances.

Atrial fibrillation (AF) is associated with significant morbidity and mortality. There are two basic approaches to managing AF: slowing the ventricular rate, while allowing the arrhythmia to continue (the rate-control approach), and restoring and maintaining sinus rhythm (the rhythm-control approach) with antiarrhythmic drugs (AADs) and/or ablation, electrical cardioversion (CV), if needed, or both. Strategy trials comparing rate and rhythm control have found no survival advantage of one approach over the other, but other considerations, such as symptom reduction, often necessitate pursuit of rhythm control. Electrical, or direct current, CV is a widely used and effective method for termination of nonparoxysmal AF, although its success can be affected by patient- and technique-related variables. Pharmacological CV options also exist and are preferable in specific circumstances. Both pharmacological and electrical CV are associated with the risk of proarrhythmia. Many AADs are under development for both CV and maintenance of sinus rhythm. Some are atrioselective, such as vernakalant, and target ion channels in the atria, with little or no effects in the ventricle. Vernakalant, currently under Food and Drug Administration review, appears to offer a safer profile than current CV agents and is likely to expand the role of pharmacological CV. Other new AADs that provide increased efficacy or safety while maintaining normal sinus rhythm may also be better than current drugs; if so, rate-rhythm comparisons will differ from those of previous studies. In conclusion, further trials should clarify the long-term safety profiles of new atrioselective agents and other investigational drugs and define their role in the treatment of AF.

An Improved QT Correction Method for use in Atrial Fibrillation and a Comparison with the Assessment of QT in Sinus Rhythm.

BACKGROUND: Conventional QT corrections may be inappropriate inatrial fibrillation (AF) due to RR variability and QT lag. Existing formulashave been modified by the formula RRmod to account for this lag. Wedeveloped a novel correction formula for use in AF (QTAF) based onthe slope ∆QT/∆RRmod and report its performance in AF.We also compare QTAF obtained in AF with rate-independentcorrections in NSR. MATERIALS AND METHODS: A total of 3063 RR/QT pairs from 28 patients with AFwere measured, 22 of whom also had measurements during sinus rhythm. QTc (theBazett equation), QTLC (the Framingham linear correction), and QTAFwere calculated utilizing RRmod, and the rate-independence of eachformula in AF tested. Mean QTAF values in AF were compared to QTintervals corrected with QTLC in normal sinus rhythm. RESULTS: ∆QTc/∆RRmod and∆QTLC/∆RRmod slopes were significantlynon-zero whereas ∆QTAF/∆RRmod was not. QTLCand QTc corrections were imperfect at extremes of RRmod whileQTAF was constant. QTAF corrections in AF were shorterthan QTc or QTLC corrections in NSR. CONCLUSIONS: QTAF is a novel QT correction with adefined relationship to correction in NSR that performs better than existingstrategies.

Comparison of autotriggered memory loop recorders versus standard loop recorders versus 24-hour Holter monitors for arrhythmia detection.

To determine the relative yields of Holter monitoring (HM), memory loop recording (MLR), and autotriggered MLR (AT-MLR), we retrospectively interrogated the very large database of Lifewatch (a Card Guard company and a commercial monitoring company) and compared the results obtained by each method. From among a total database of approximately 100,000 patients, records of 1,800 patients from 2003 were randomly selected and examined, 600 from each of the 3 different monitoring groups. Each session of MLR and AT-MLR was applied for 30 days. For each patient we determined the symptomatic and asymptomatic events that were documented, including those that met predefined immediate physician notification criteria and the time to first notification event. The groups were identical in age and symptoms that necessitated monitoring; fewer women had HM. Information on the type of underlying structural heart disease, if present, and medications taken, if any, was not available to us in this database. The AT-MLR approach provided a higher yield of diagnostic events (e.g., 37, 108, and 216 total patients who had events; 37, 212, and 524 total events; and 6.2%, 17%, and 36% with a diagnostic yield for HM, MLR, and AT-MLR, respectively) and an earlier diagnosis. AT-MLR was also the most effective technique for capturing asymptomatic significant events, such as atrial fibrillation (52 with AT-MLR vs 1 for standard MLR). AT-MLR detected more than half as many asymptomatic episodes of atrial fibrillation (n = 52) as the total number of symptomatic episodes detected by patient activated recording (n = 94), thus confirming the common presence of asymptomatic atrial fibrillation. AT-MLR provided electrocardiographic documentation of tachyarrhythmias (n = 392) more often than MLR (n = 47) or HM (n = 44) and bradyarrhythmias/pauses/atrioventricular block (n = 38) more often than MLR (n = 13) or HM (n = 18). Thus, MLR and AT-MLR provide a diagnosis more often than does HM, thus confirming the benefit of prolonged monitoring. Further, the higher yield of AT-MLR versus MLR demonstrates the significantly enhanced benefit of autotriggered programmable recording.

Will direct thrombin inhibitors replace warfarin for preventing embolic events in atrial fibrillation?

PURPOSE OF REVIEW: Atrial fibrillation is the most frequently encountered tachyarrhythmia requiring therapy. Treatment issues include therapy for any reversible cause; the identification and treatment of any underlying structural disorder; control of the ventricular rate, both for symptom reduction and prevention of tachycardic-induced cardiomyopathy; restoration and maintenance of sinus rhythm when symptoms persist despite rhythm control; and anticoagulation in patients with high-risk markers for systemic embolization: age over 65 years, hypertension, diabetes, ventricular failure, rheumatic valvular disease, and prior stroke or other embolic event. In such patients, anticoagulation with warfarin is currently recommended. Warfarin therapy carries significant risks (especially bleeding), inconveniences (the cost of prothrombin time monitoring, the need for rigid dietary stability, the concerns of drug and herbal interactions), and other concerns (the issue of generic formulation substitution). RECENT FINDINGS: Under development are oral thrombin inhibitors. The first to reach clinical approval will likely be ximelagatran. In clinical trials to date, ximelagatran has proven to be equal to or superior to warfarin in the prevention and treatment of thrombophlebitis. In atrial fibrillation patients, the Stroke Prevention Using Oral Thrombin Inhibitor in Atrial Fibrillation (SPORTIF) trials completed so far appear to show a similar or better efficacy for ximelagatran versus warfarin as regards both prevention of embolic events and lower risks of major bleeding, with no serious adverse effects except for apparently reversible alterations in liver function tests in approximately 6% of subjects, all occurring early in therapy to date. If the remaining SPORTIF trial (SPORTIF V) is confirmatory (results to be available in late 2003), it is expected that this exciting new product will be submitted this winter to the Food and Drug Administration for approval. Recent findings also include the observations in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) and Rate Control Versus Electrical Cardioversion (RACE) trials that anticoagulation should not be discontinued despite the restoration and maintenance of sinus rhythm. SUMMARY: Oral direct thrombin inhibitors, such as ximelagatran, appear likely to replace the use of warfarin in most patients in the near future, because of a better risk-benefit profile.