Impact of obesity on atrial fibrillation ablation: Patient characteristics, long-term outcomes, and complications

Abstract

Background: There is an association between obesity and atrial fibrillation (AF). The impact of obesity on AF ablation procedures is unclear.

Objective: The purpose of this study was to evaluate the influence of body mass index (BMI) on patient characteristics, long-term ablation outcomes, and procedural complications.

Methods: We evaluated 2715 patients undergoing 3742 AF ablation procedures. BMI was ≥30 kg/m² in 1058 (39%) and ≥40 kg/m² in 129 (4.8%). Patients were grouped by BMI ranges (<25, 25-<30, 30-<35, 35-<40, and ≥40 kg/m²).

Results: As BMI increased from <25 to ≥40 kg/m², age decreased from 65.3 ± 11.2 to 61.2 ± 9.2 years (P < .001), left atrial size increased from 3.91 ± 0.68 to 4.72 ± 0.62 cm (P < .005), and CHADS₂ scores increased from 1.24 ± 1.10 to 1.62 ± 1.09 (P < .001). As BMI increased, paroxysmal AF decreased from 48.0% to 16.3% (P < .0001) and there was an increase in dilated cardiomyopathy (from 7.6% to 12.4%; P < .0001), hypertension (from 41.0% to 72.9%; P < .0001), diabetes (from 4.3% to 23.3%; P < .0001), and sleep apnea (from 7.0% to 46.9%; P < .0001). For the entire cohort, for BMI ≥35 kg/m² the 5-year ablation freedom from AF decreased from 67%-72% to 57% (P = .036). For paroxysmal AF, when BMI was ≥40 kg/m² ablation success decreased from 79%-82% to 60% (P = .064), and for persistent AF, when BMI was ≥35 kg/m² ablation success decreased from 64%-70% to 52%-57% (P = .021). For long-standing AF, there was no impact of BMI on outcomes (P = .624). In multivariate analysis, BMI ≥35 kg/m² predicted worse outcomes (P = .036). Higher BMI did not impact major complication rates (P = .336). However, when BMI was ≥40 kg/m², minor (from 2.1% to 4.4%; P = .035) and total (from 3.5% to 6.7%; P = .023) complications increased.

Conclusion: In patients undergoing AF ablation, increasing BMI is associated with more patient comorbidities and more persistent and long-standing AF. BMI ≥35 kg/m² adversely impacts ablation outcomes, and BMI ≥40 kg/m² increases minor complications.

Keywords: Ablation; Ablation outcomes; Atrial fibrillation; Body mass index; Obesity.