Secular trends in success rate of catheter ablation for atrial fibrillation: The SMASH-AF cohort

Abstract

Background: Approaches, tools, and technologies for atrial fibrillation (AF) ablation have evolved significantly since its inception. We sought to characterize secular trends in AF ablation success rates.

Methods: We performed a systematic review and meta-analysis of AF ablation from January 1, 1990, to August 1, 2016, searching PubMed, Scopus, and Cochrane databases. Major exclusion criteria were insufficient outcome reporting and ablation strategies that were not prespecified and uniform. We stratified treatment arms by AF type (paroxysmal AF; nonparoxysmal AF) and analyzed single-procedure outcomes. Multivariate meta-regressions analyzed effects of study, patient, and procedure characteristics on success rate trends. Registered in PROSPERO (CRD42016036549).

Results: A total of 180 trials and observational studies with 28,118 patients met inclusion. For paroxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 73.1% in 2003 to 77.1% in 2016, increasing by 0.9%/year (95% CI 0.4%-1.4%; P = .001; I² = 90%). After controlling for study design and patient demographics, rate of improvement in success rate summary estimate increased (1.6%/year; 95% CI 0.9%-2.2%; P = .001; I² = 87%). For nonparoxysmal AF ablation studies, unadjusted success rate summary estimates ranged from 70.0% in 2010 to 64.3% in 2016 (1.1%/year; 95% CI -1.3% to 3.5%; P = .37; I² = 85%), with no improvement in multivariate analyses.

Conclusions: Despite substantial research investment and health care expenditure, improvements in AF ablation success rates have been incremental. Meaningful improvements may require major paradigm or technology changes, and evaluation of clinical outcomes such as mortality and quality of life may prove to be important going forward.

Figure 1

Flow diagram.Inclusion and exclusion criteria used to select analysis cohort. AT, atrial tachycardia; CTI, cavotricuspid isthmus; SVC, superior vena cava. N = study number.

Figure 2

Secular trends in success rate for PAF ablation studies. Studies of PAF ablation (155 studies, 24,477 patients), with unadjusted summary estimates reported by year. Unadjusted analysis (solid line): (0.9%/year; 95% CI 0.4%−1.4%; P = .001; I² = 90%). Adjusting for 12-month follow-up duration (dashed line): (1.0%/year; 95% CI 0.5%−1.5%; P < .001; I² = 90%). N = treatment arms, P = patients.

Figure 3

Secular trends in success rate for NPAF ablation studies. Studies of NPAF ablation (32 studies, 3,641 patients), with unadjusted summary estimates reported by year. Unadjusted analysis (solid line): (1.1%/year; 95% CI −1.3% to 3.5%; P = .37; I² = 85%) (solid line). Adjusting for 12-month follow-up duration (dashed line): (1.4%/year; 95% CI −1.0% to 3.7%; P = .25; I² = 84%). N = treatment arm, P = patients.