Risk Factors for Recurrence of Atrial Fibrillation in Horses After Cardioversion to Sinus Rhythm. (27th April 2015)

• Record Type: Journal Article
• Authors: Decloedt, A.; Schwarzwald, C.C.; De Clercq, D.; Van Der Vekens, N.; Pardon, B.; Reef, V.B.; van Loon, G.
• Is Part Of: Journal of veterinary internal medicine. Volume 29:Number 3(2015:May/Jun.)
• Page Start: 946
• Page End: 953
• Publication Date: 2015-04-27
• Subjects: Veterinary medicine -- Periodicals; 636.0896
• DOI: 10.1111/jvim.12606
• Languages: English
• ISSNs: 0891-6640

Abstract

<abstract abstract-type="main" id="jvim12606-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jvim12606-sec-0001" sec-type="section"> <title>Background</title> <p>Although atrial fibrillation (AF) can be successfully treated in horses, recurrence occurs frequently. In humans, atrial function after cardioversion can predict recurrence.</p> </sec> <sec id="jvim12606-sec-0002" sec-type="section"> <title>Objectives</title> <p>To examine the prognostic value of atrial mechanical function at 24 hours after cardioversion and other potential predictor variables for AF recurrence in horses.</p> </sec> <sec id="jvim12606-sec-0003" sec-type="section"> <title>Animals</title> <p>117 horses treated for AF at 4 referral centers.</p> </sec> <sec id="jvim12606-sec-0004" sec-type="section"> <title>Methods</title> <p>Retrospective study. Inclusion criteria were successful cardioversion, echocardiography at 24 hours after cardioversion and ≥4 months follow‐up. To determine factors associated with AF recurrence, a multivariable survival model was built.</p> </sec> <sec id="jvim12606-sec-0005" sec-type="section"> <title>Results</title> <p>133 AF episodes in 117 horses were included. AF recurred in 36/100 horses with a first AF episode and in 57/133 AF episodes overall. Factors associated with recurrence in horses with a first episode were previous unsuccessful treatment attempt (hazard ratio HR 2.36, 95% confidence interval CI 1.11–4.99, <italic>P</italic> = .025) and mild or moderate mitral regurgitation (HR 2.70, 95% CI 1.23–5.91, <italic>P</italic> = .013). When the last AF episode of all horses was included, previous AF (HR 2.53, 1.33–4.82, <italic>P</italic> = .005) and active left atrial fractional area change ≤9.6% (HR 3.43, 1.22–9.67, <italic>P</italic> = .020) were significant predictors.</p> </sec> <sec id="jvim12606-sec-0006" sec-type="section"> <title>Conclusions and Clinical Importance</title> <p>The only echocardiographic variable of left atrial function with significant prognostic value for recurrence was low active left atrial fractional area change. Further research is necessary to evaluate whether echocardiography at a later timepoint could provide more prognostic information.</p> </sec> </abstract>