Progression of atrial fibrillation: can we prevent it? Early catheter ablation will stop progression of atrial fibrillation pro

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1 Progression of atrial fibrillation: can we prevent it? Early catheter ablation will stop progression of atrial fibrillation pro Jerónimo Farré MD, Madrid, ES

2 AF: the kingdom of wishful thinking In AF we hold beliefs and make decisions not based on evidences, that are lacking, but on what we consider rational in spite of not being scientifically demonstrated

3 Catheter ablation (guidelines 2006) Catheter ablation is a reasonable alternative to pharmacological therapy to prevent recurrent AF in symptomatic patients with little or no LA enlargement. (class IIa, LOE C) LOE C and rather vague statements Circulation. 2006;114: For rhythm control, drugs are typically the first choice and LA ablation is a second-line choice 2. In some patients, especially young persons with very symptomatic AF who need sinus rhythm, radiofrequency ablation may be preferred over years of drug therapy 3. Catheter ablation should be considered to maintain sinus rhythm in selected patients who failed to respond to antiarrhythmic drug therapy

4 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

5 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

6 AFFIRM on treatment analysis Circulation. 2004;109: In an intention-to-treat analysis, AFFIRM showed that rhythm-control offered no survival advantage over rate-control and that there were potential advantages with rate-control (lower risk of adverse drug effects) on-treatment analysis of the relation of survival to cardiac rhythm and treatment 1. Warfarin improves survival 2. SR is a determinant of survival (HR 0.53) or a marker for other factors associated with survival 3. AADs increase mortality (HR 1.49) If an effective method for maintaining SR with fewer adverse effects were available, it might be beneficial

7 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

8 RFCA better than AAD Rx for RC J Cardiovasc Med 2010, 11: Eur Heart J 2010; 31: Circ Arrhyth Electrophysiol. 2009;2: controlled and historical studies have shown that ablation is more successful than AAD therapy in maintaining sinus rhythm

9 Meta-analysis: RFCA vs AAD Rx Jerónimo Farré MD 2010 the results of this metaanalysis [8 studies] favor ablation over AAD therapy J Cardiovasc Med 2010, 11:

10 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

11 Experimental AF results in molecular, electrophysiological, and structural changes in the atrial myocytes and interstitial matrix that facilitate perpetuation of AF It would be rational to intervene at a time the AF-induced remodeling is minimal Experimental studies on AF Circulation 1995; 91: Circulation 1997;96: Circulation 1999;100:87-95 J Am Coll Cardiol 2006; 47:

12 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

13 LA remodeling in AF MRI DE in 81 pts 41 PAF 40 persistent AF Mild LE ( 15% of the LA) 43 Moderate LE (15-35% of LA) 30 Extensive LE (>35% of LA) 8 Nassir F Marrouche Circulation. 2009;119: All patients with extensive LE had persistent AF

14 LA remodeling in AF Extensive LE and large low voltage areas Circulation. 2009;119: % 63%

15 LA remodeling and recurrence there seems to be a relation between the duration of AF, the extent of remodelling, and the risk of recurrence of AF after catheter ablation Circulation. 2009;119:

16 LA remodeling in AF: limitations Nassir F Marrouche Circulation. 2009;119: Sample size relatively small 2. Technology complex and subjected to potential inaccuracies - Software used - Investigators (selection of thresholds for the algorithm of detection) - Limited spatial resolution of 1.5T MRI scanner - Respiratory artifacts - MRI noise

17 Ongoing studies: DECAAF Delayed-Enhancement MRI (DE-MRI) Determinant of Successful Radiofrequency Catheter Ablation of Atrial Fibrillation multi-center, 1-year prospective cohort study (1 year follow-up, at 3, 6 and 12 month) recruiting 675 participants DE-MRI within 30 days prior to the AF ablation procedure to quantify atrial structural remodeling or fibrosis pre-ablation DE-MRI at 3, 6, and 12 months follow-up to detect and quantify ablation-related scar formation Study Start Date July 2010 Estimated Study Completion Date June 2012

18 What do we know? 1.Rhythm control has not been shown to be better than rate control, but 2.Ablation is more successful than AAD Rx in maintaining SR 3.AF begets AF in the experimental setting 4.Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5.Successful ablation reduces LA dimensions, does not seem to impair atrial function, and improves systolic LV function

19 Effect of ablation on LA in AF Am J Cardiol 2010;105: Meta-analysis from 17 studies (enrolling 869 patients) 1. significant decreases in LA diameter and volumes only in successful cases 2. no significant differences in LA ejection fraction and active emptying fraction in successful cases but both decreased in patients with AF recurrence

20 Limitations of studies on remodeling 1. Variations in - imaging techniques - methodologies of measurement - ablation strategies - amount of scar - follow-up durations - duration of sinus rhythm post ablation - degree of AF burden 2. LA function measured only during sinus rhythm - only in patients in sinus rhythm at the time of imaging before and after ablation days post ablation as control [?]

21 Reverse remodeling after RFCA Michel Haïssaguerre 48 patients with isolated AF studied by serial ECHOCG at baseline and at 1-, 3-, 6-, 9-, and 12-month intervals after radiofrequency ablation Circulation. 2005;112:

22 LV reverse remodeling & normal EF 30 pts isolated paroxysmal AF [AF] 30 controls [C] ECHO before and at 1-day, 1-m, 6-m, 12-m after RFCA LV systolic function: LVEF & 2-D strain Before ablation - LVEF, transverse & radial strains normal in [AF] and [C] - global longitudinal & circumferential strains lower in [AF] than [C] At 12 months - global longitudinal & circumferential strains were significantly improved in [AF] Michel Haissaguerre Am J Cardiol 2009;103: Pts with PAF and normal LVEF have systolic function abnormalities 2. These abnormalities improve after AF ablation

23 AF and HeF: candidates to RFCA? 58 consecutive patients with AF and - Hx of congestive heart failure and - LVEF <45% undergoing catheter ablation for AF 58 control patients without heart failure who underwent ablation for AF matched according to age, sex, and type AF Michel Haissaguerre N Engl J Med 2004;351: Restoration and maintenance of sinus rhythm by catheter ablation without the use of drugs in patients with congestive heart failure and AF significantly improved cardiac function, symptoms, exercise capacity, and quality of life.

24 AF and HeF: candidates to RFCA? N Engl J Med 2004;351: LVEF after Ablation in Heart Failure

25 Conclusions 1. In spite that rhythm control has not been shown to be better than rate control, SR maintenance is a marker for an improved survival 2. Ablation is more successful than AAD Rx in maintaining SR 3. AF begets AF 4. Atrial remodeling is greater in permanent than in paroxysmal AF, and the degree of atrial remodeling predicts post-ablation recurrence of AF 5. Successful ablation reduces LA dimensions without impairing atrial function, and improves systolic LV function The sooner the better delaying ablation too much may reduce its efficacy