Elsevier

Canadian Journal of Cardiology

Volume 27, Issue 6, November–December 2011, Pages 787-793
Canadian Journal of Cardiology

Clinical research
Association of Rate-Controlled Persistent Atrial Fibrillation With Clinical Outcome and Ventricular Remodelling in Recipients of Cardiac Resynchronization Therapy

https://doi.org/10.1016/j.cjca.2011.06.004Get rights and content

Abstract

Background

Whether patients with persistent atrial fibrillation (AF) obtain the same degree of benefit with cardiac resynchronization therapy (CRT) as those in sinus rhythm remains unclear.

Methods

We enrolled 93 patients undergoing CRT implantation, 20 (22%) of whom had rate-controlled persistent AF. The primary endpoint was CRT response defined as 1 class improvement in Specific Activity Scale and 15% reduction in left ventricular end-systolic volume (LVESV) during 12 months. Other endpoints included changes in 6-minute walk distance, quality of life, B-type natriuretic peptide, and survival.

Results

Baseline characteristics were similar in those with and without AF. Response to CRT was observed in 42% vs 54% of those with and without AF, respectively (P = 0.3). Both groups had significant improvements in 6-minute walk distance, quality of life, and LVESV, but the improvement in LVESV was smaller in those with AF (13.7% ± 14.9% vs 27.7% ± 23.7%; P = 0.02). During 2.8 ± 1.4 years of follow-up, AF was associated with a 2.2-fold increased risk of death or transplantation (95% confidence interval, 1.2-3.9; P = 0.01).

Conclusions

Compared with patients without rate-controlled persistent AF, those with rate-controlled persistent AF had similar rates of clinical improvement but less left ventricular reverse remodelling in the first year after CRT. AF was associated with a markedly higher risk of death or transplantation in long-term follow-up. Given these findings, randomized studies assessing CRT efficacy in those with AF are warranted.

Résumé

Introduction

Que les patients ayant une fibrillation auriculaire (FA) persistante obtiennent les mêmes avantages par la thérapie de resynchronisation cardiaque (TRC) que ceux maintenus en rythme sinusal demeure obscur.

Méthodes

Nous avons inscrit 93 patients ayant subi l'implantation d'un dispositif de TRC, dont 20 (22 %) ont eu une FA persistante contrôlée par la fréquence. Le critère d'évaluation principal a été la réponse à la TRC définie comme une amélioration de la classification dans l'échelle de l'activité spécifique et une réduction de 15 % dans le volume télésystolique (VTS) durant 12 mois. Les autres critères d'évaluation ont inclus des changements dans le test de marche de 6 minutes, la qualité de vie, le peptide natriurétique de type B et la survie.

Résultats

Les caractéristiques de base ont été similaires chez les patients présentant ou non une FA. La réponse à la TRC a été observée dans 42 % vs 54 % des patients présentant ou non une FA, respectivement (P = 0,3). Les deux groupes ont eu des améliorations importantes dans le test de marche de 6 minutes, la qualité de vie et le VTS, mais l'amélioration du VTS a été plus petite chez ceux présentant une FA (13,7 % ± 14,9 % vs 27,7 % ± 23,7 %; P = 0,02). Durant 2,8 ± 1,4 ans de suivi, la FA a été associée à 2,2 fois plus de risque de décès ou de transplantation (intervalle de confiance de 95 %, 1,2-3,9; P = 0,01).

Conclusions

Comparativement aux patients ne présentant pas de FA persistante contrôlée par la fréquence, ceux présentant une FA persistante contrôlée par la fréquence ont eu des taux d'amélioration clinique similaires, mais moins de remodelage inverse du ventricule gauche la première année après la TRC. La FA a été associée à un risque beaucoup plus marqué de décès ou de transplantation durant le suivi à long terme. En raison de ces découvertes, les études aléatoires évaluant l'efficacité de la TRC chez les patients présentant une FA sont justifiées.

Section snippets

Patient population

This report is a post hoc analysis of data from the Effect of Targeting Left Ventricular Lead Position on the Rate of Response to CRT study (INCREMENTAL; ClinicalTrials.gov identifier NCT00399594). INCREMENTAL was a pilot randomized trial comparing LV lead placement targeted to the latest-activated segment on preprocedure tissue-Doppler echocardiography with standard lead positioning. Enrollment criteria included New York Heart Association (NYHA) class 3 or 4 limitation due to heart failure, LV

Results

The study enrolled 96 patients between December 2004 and March 2007. Of these, 3 patients did not have successful CRT implantation and were excluded. A further 7 patients died (4 of heart failure and 1 of noncardiac causes) or underwent cardiac transplant (n = 2) prior to the 2-month follow-up visit and were included for survival analysis but excluded from analyses of CRT response. One of these patients had AF at baseline. The remaining 86 patients had complete follow-up, with vital status

Discussion

Using a composite of symptomatic improvement and LV reverse remodelling, we find that patients with and without rate-controlled persistent AF have a similar likelihood of responding to CRT in the first year of treatment. In fact, symptomatic benefit was sustained for 1 year in at least 70% of patients in both groups, with parallel improvements in 6MWD and health-related QOL. However, those in the persistent AF group had significantly less improvement in LVESV, despite the fact that they were a

Funding Sources

The study was funded by the Canadian Institutes of Health Research (CIHR). Additional unrestricted grants in aid were received from Medtronic of Canada and Roche Diagnostics. Dr Wilton is funded by the CIHR Randomized Controlled Trials Mentoring Program, Ottawa. Dr Exner is a Scholar of the Alberta Heritage Foundation for Medical Research.

Disclosures

Dr Yee is a consultant to and is the recipient of research grants from Medtronic Inc. Dr Exner has received honouraria and research support from Medtronic and St Jude Medical, honouraria from Boston Scientific, and research support from Sorin/ELA.

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