Invasive haemodynamic assessment shows the obesity-HFpEF phenotype is common amongst patients with symptomatic AF

Abstract Background The obesity-HFpEF phenotype is a unique form of heart failure associated with elevated LA and RA pressures, cardiac remodelling and poor exercise capacity. The influence of this HFpEF phenotype amongst patients with AF is unknown. Objective We sought to determine the influence of the obesity-HFpEF phenotype amongst patients with symptomatic AF, using invasive testing, imaging and cardiopulmonary exercise testing to assess haemodynamics, cardiac remodelling and exercise capacity in patients undergoing AF ablation. Methods Consecutive patients with symptomatic AF due to undergo an AF ablation procedure were recruited. Participants were grouped according to the presence of obesity if body mass index (BMI) exceeded 30kg/m2. Mean LA pressure (mLAP) and mean RA pressure (mRAP) were measured invasively at AF ablation and HFpEF was defined as mLAP>15mmHg at rest or after infusion of 500mls saline. Cardiac remodelling was assessed using transthoracic echocardiography. Exercise capacity was evaluated using cardiopulmonary exercise testing and AF symptoms and quality of life were assessed using the AF Symptom Severity Questionnaire. Results Of 120 participants, 44 (36.7%) were obese and 76 (63.3%) were non-obese (Table 1). Despite younger age (p=0.003), obese participants were more likely to have a coexistent diagnosis of HFpEF (84.1% vs 67.1%, p=0.043). In addition to higher mLAP (p<0.001), obesity was associated with higher mRAP (p<0.001) compared to non-obese patients. Obesity was not associated with differences in LV volume (p=0.559) or function (p=0.381) but was associated with larger LA volumes (p=0.032). On functional assessment, obese participants demonstrated a higher burden of AF symptoms (p=0.049), poorer quality of life (p=0.017) and a trend towards reduced exercise capacity (p=0.068). Conclusion Obese patients with AF demonstrate characteristic features of the obesity-HFpEF phenotype, including elevated LA and RA pressure, left atrial enlargement and poorer functional capacity. Novel treatments for the obesity-HFpEF phenotype, such as GLP-1 inhibitors, may be useful in obese patients with AF.