Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Catheter ablation (CA) has become first line therapy for patients with symptomatic AF.
Overweight/ obesity are both a common comorbidity and risk factor for AF, as they promote atrial remodeling. Atrial remodeling can lead to left-atrial (LA) – dysfunction. LA reservoir strain (LArS) is suggested to be a sensitive marker for LA-function. However, data on body mass index (BMI) – related differences in LA-function in the context of CA are limited.
Purpose: To evaluate the relationship of BMI and LA-function and analyze in relation to the outcome after CA for AF.
Methods: Patients with symptomatic AF undergoing first CA for AF between 2018 and 2024 were included. Inclusion criteria were as following: No prior CA in the LA, pre- and postprocedural transthoracic echocardiography (TTE) in continuous sinus rhythm (SR) of adequate image quality and follow-up information about postprocedural outcome after blanking period. LA strain analysis was performed for pre- and postprocedural TTE. Clinical as well as procedural parameters were retrospectively analyzed. BMI & postprocedural outcome after CA were correlated with biomarkers and parameters of LA-function. Correlation between BMI and markers of LA-function was assessed using spearman`s rho.
Results: The study population comprised 220 patients, with 30% of patients having normal weight (NW) (BMI< 25kg/m2, n=66), 42% being overweight (OW) (BMI 25-29.9kg/m2, n=93), and 28% of patients being obese (OB) (BMI≥30kg/m2, n=61).
Higher BMI was neither associated with alterations of preprocedural LArS (ρ=-0.015, P=0.82), nor LAVI (ρ=0.097, P=0.15), nor NT-proBNP (ρ=-0.058, P=0.406).
Within 12 months follow up recurrence rate was 32%. There were no differences across BMI categories (NW: 32%, OW: 30%, OB: 34%; log rank: χ2=0.703, P=0.704).
In contrast, patients with recurrence of AF (n=70) showed significantly impaired markers of LA-function in comparison to patients without recurrence: Reduced preprocedural LArS (Recurrence: 20.09 ± 6.37% vs. No recurrence: 24.19 ± 6.77 %, P<0.001), higher values for preprocedural LAVI (Recurrence: 41.90 [27.95 – 51.10] ml/m2 vs. No recurrence: 35.05 [26.60 – 44.75] ml/m2, P<0.046) and preprocedural NT-proBNP (Recurrence: 853.00 [294.00 – 2011.00] pg/dl vs. No recurrence: 386.00 [170.00 – 874.00] pg/dl, P<0.001).
Multivariate regression analysis – including sex, age, comorbidities, BMI and markers of LA-function – revealed only preprocedural LArS to be an independent predictor of AF recurrence after CA (OR 0.891, 95% CI: 0.838-0.947; P<0.001).
Conclusion: In our cohort, no significant correlations were observed between BMI and markers of LA-function. Outcome after CA was not influenced by BMI category of the patient. Yet, patients with impaired markers of LA-function showed higher recurrence rates after CA. Lager studies are needed to confirm these findings.
