Elevated BMI may up recurrent AF risk

Among patients who had previously undergone ablation for atrial fibrillation (AF), the risk of recurrent AF increased with rising body mass index (BMI), according to a study from Denmark presented at EHRA 2022.

The researchers used Danish nationwide registries to identify all Danish adults who first underwent ablation for AF between January 2010 and December 2018 (n=9,229). Patients were divided according to five categories of BMI ie, underweight (<18.5 kg/m²), normal weight (18.5–24 kg/m²), overweight (25–29 kg/m²), obese (30–34 kg/m²), and morbidly obese (>34 kg/m²).

Patients in the normal weight group tended to be older than those in the morbidly obese group (median age 64 vs 60 years). More patients who were morbidly obese than of normal weight had a CHA₂DS₂­VASc score ≥2 (65 percent vs 48 percent). The use of Class 1C anti­arrhythmic medication did not differ according to BMI groups (14.3–16.3 percent), while the use of amiodarone increased with rising BMI (15.5, 19.3, 26.3, and 29.7 percent of the normal weight, overweight, obese, and morbidly obese groups, respectively).

Compared with patients of normal weight, the 1-year cumulative incidence of recurrent AF, defined as a composite of claimed anti-arrhythmic drug prescriptions, hospitalization for AF, re­ablation, or electrical cardioversion, significantly increased with increasing BMI (hazard ratio* [HR], 1.19, 95 percent confidence interval [CI], 1.10–1.28; HR, 1.22, 95 percent CI, 1.11–1.34; and HR, 1.32, 95 percent CI, 1.16–1.50 for patients who were overweight, obese, and morbidly obese, respectively; p<0.001 for all). [EHRA 2022, abstract N° 40577]

The 5-year cumulative incidence of recurrent AF was similarly increased with rising BMI vs normal weight (HR, 1.15, 95 percent CI, 1.07–1.23; HR, 1.18, 95 percent CI, 1.09–1.28; and HR, 1.26, 95 percent CI, 1.13–1.41 for patients who were overweight, obese, and morbidly obese, respectively; p<0.001 for all vs normal weight patients).

“The study shows that recurrence rates of AF increased incrementally with rising BMI at short- and long-term follow-up,” said lead author Dr Jacob Tønnesen from the Gentofte University Hospital, Gentofte, Denmark.

“For instance, after 1 year, 61 percent of normal weight patients were still free of the heart rhythm disorder compared to just 52 percent of morbidly obese patients. We also observed that both procedure duration and X-ray dose increased with rising BMI,” he commented.

The incidence of recurrent AF at 1 and 5 years was elevated in underweight vs normal weight patients, though the results were not significant (HR, 1.38, 95 percent CI, 0.90–2.11; p=0.134 and HR, 1.29, 95 percent CI, 0.88–1.91; p=0.196 at 1 and 5 years, respectively).

“[The] link between BMI and AF recurrence after ablation is poorly elucidated,” noted Tønnesen. “The strength of association between high BMI and repeat AF after ablation was comparable to the influence of well-known factors like heart failure, COPD, and hypertension which are typically treated in these patients.”

“Therefore, aggressive pre-ablation weight management in overweight patients could potentially provide substantial benefits and improve short- and long-term outcomes after ablation,” Tønnesen concluded.