Trends in atrial fibrillation ablation: have we maximized the current paradigms?

Abstract

Purpose: The purpose of this study was to evaluate how atrial fibrillation (AF) ablation has evolved over time with regards to patient characteristics, procedural variables, complications, and outcomes.

Methods: We evaluated trends over time from 2003 to 2010 in clinical characteristics, procedural variables, complications, and Kaplan-Meier AF-free rates after the initial and final AF ablation in 1,125 patients undergoing 1,504 ablations.

Results: Evaluating trends from 2003 to 2010, we found that patients undergoing AF ablation became older (P < 0.0001), had higher CHADS(2) scores (P < 0.0001), and more coronary artery disease (P = 0.021), persistent AF (P < 0.0001), hypertension (P < 0.0001), and previous strokes/transient ischemic attacks (P = 0.005). Procedure times decreased from 256 ± 49 to 122 ± 28 min (P < 0.0005), fluoroscopy times decreased from 134 ± 29 to 56 ± 19 min (P < 0.0005), and major (P = 0.023), minor (P = 0.023), and total complications (P = 0.001) decreased over time. The learning curve to minimize complications was 6 years. For paroxysmal AF, initial ablation AF-free rates improved over time (P = 0.015) but improvement plateaued in recent years. For persistent AF, initial ablation AF-free rates trended toward improvement over time (P = 0.062) but also plateaued in recent years. For long-standing persistent AF (P = 0.995), there was no outcome improvement after initial ablation over time. There was no trend for improved final outcomes (including repeat ablations) over time for paroxysmal, persistent, or long-standing AF (P = 0.150 to P = 0.978).

Conclusions: Despite decreased procedural and fluoroscopy times and reduced complication rates, post-ablation freedom from AF has not improved commensurately in recent years. A better understanding of AF initiation and maintenance may be required to devise personalized approaches to AF ablation and further improve outcomes.

Fig. 1

Percentage of AF patients with each type of AF (green = paroxysmal AF1, blue = persistent AF2, and black = long-standing persistent AF3) by year of initial ablation

Fig. 2

Changes in procedure and fluoroscopy time (green = procedure time, blue = fluoroscopy time) by year of initial ablation

Fig. 3

Decline in average procedural ACT by year

Fig. 4

Kaplan–Meier curves for freedom from AF after initial AF ablation by year ((A) paroxysmal AF1, (B) persistent AF2, (C) long-standing persistent AF3). Blue = 2003–2004, purple = 2005, red = 2006, green = 2007, black = 2008, gray = 2009, yellow = 2010

Fig. 5

Kaplan–Meier curves for freedom from AF after the last AF ablation by year of last ablation. (A) Paroxysmal AF1, (B) persistent AF2, (C) long-standing persistent AF3. Color code the same as Fig. 4

Fig. 6

Percent of AF ablations with major (red) and minor (blue) complications by year. The black line represents the total complications (major + minor) by year