| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Circulation. 2006;114:1703-1712.)
© 2006 American Heart Association, Inc.
Heart Failure |
From Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, Calif.
Correspondence to Jeffrey E. Olgin, MD, University of California, San Francisco, 500 Parnassus Ave, MU East 4, Box 1354, San Francisco, CA 94143. E-mail olgin{at}medicine.ucsf.edu
Received March 2, 2006; revision received August 16, 2006; accepted August 18, 2006.
Background Atrial fibrosis is an important substrate in atrial fibrillation (AF), particularly in the setting of structural heart disease. In a canine model, congestive heart failure (CHF) produces significant atrial fibrosis and the substrate for sustained AF. This atrial remodeling is a potential therapeutic target. The objective of the present study is to evaluate the effects of the antifibrotic drug pirfenidone (PFD) on arrhythmogenic atrial remodeling in a canine CHF model.
Methods and Results We studied 15 canines, divided equally into 3 groups: control, CHF canines not treated with PFD, and CHF canines treated with PFD. CHF was induced by ventricular tachypacing (220 bpm for 3 weeks), and oral PFD was administered for the 3-week pacing period. We performed electrophysiology and AF vulnerability studies, atrial fibrosis measurements, and atrial cytokine expression studies. Only canines in the untreated CHF group developed sustained AF (>30 minutes, 4 of 5 canines; P<0.05). Treatment of CHF canines with PFD resulted in an attenuation of arrhythmogenic left atrial remodeling, with a significant reduction in left atrial conduction heterogeneity index (median [25% to 75% interquartile range] 4.96 [3.53 to 5.64] versus 2.52 [2.11 to 2.82], P<0.01; pacing cycle length 300 ms), left atrial fibrosis (16.0% [13.0% to 17.5%] versus 8.7% [5.7% to 10.6%], P<0.01), and AF duration (1800 [1020 to 1800] seconds versus 6 [5 to 22] seconds, P<0.01). Immunoblotting studies demonstrated the drugs effects on multiple cytokines, including a reduction in transforming growth factor-ß1 expression.
Conclusions Treatment of CHF canines with PFD results in significantly reduced arrhythmogenic atrial remodeling and AF vulnerability. Pharmacological therapy targeted at the fibrotic substrate itself may play an important role in the management of AF.
This article has been cited by other articles:
![]() |
I. Savelieva and J. Camm Anti-arrhythmic drug therapy for atrial fibrillation: current anti-arrhythmic drugs, investigational agents, and innovative approaches Europace, June 1, 2008; 10(6): 647 - 665. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Nattel, B. Burstein, and D. Dobrev Atrial Remodeling and Atrial Fibrillation: Mechanisms and Implications Circ Arrhythmia Electrophysiol, April 1, 2008; 1(1): 62 - 73. [Full Text] [PDF] |
||||
![]() |
B. Burstein and S. Nattel Atrial Fibrosis: Mechanisms and Clinical Relevance in Atrial Fibrillation J. Am. Coll. Cardiol., February 26, 2008; 51(8): 802 - 809. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Casaclang-Verzosa, B. J. Gersh, and T. S.M. Tsang Structural and functional remodeling of the left atrium: clinical and therapeutic implications for atrial fibrillation. J. Am. Coll. Cardiol., January 1, 2008; 51(1): 1 - 11. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2006 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |