Abstract 57: Impact Of Body Mass Index In Functional Capacity And Hemodynamics In Patients With Pulmonary Arterial Hypertension

Abstract

Background: Prior studies demonstrate a higher prevalence of pulmonary hypertension (PH) and more severe hemodynamics in patients with higher body mass index (BMI). However, this association was only described in post-capillary PH. To better understand the relationship between pre-capillary PH and BMI, we compared various PH parameters stratified by BMI class. Methods: Data from right heart catheterization (RHC), 6-minute walk (6MW), and functional class (FC) were collected from the University of Michigan Pulmonary Hypertension Patient Registry from 2016-2020 at baseline and 3-month follow-up. Group 1 pulmonary arterial hypertension (PAH) patients were grouped into 4 BMI weight classes: under/normal weight (BMI < 25), overweight (25 < BMI < 30), obesity class 1 (30 < BMI < 35), obesity class 2/3 (BMI > 35). Results: Among 175 PAH patients, obese patients exhibited higher right atrial and pulmonary capillary wedge pressures. There were no major differences in mean pulmonary artery (PA) pressures, pulmonary vascular resistance (PVR), cardiac index Fick, 6MW distance walked, or peak Borg Dyspnea score among BMI groups. Despite having similar mean PA pressure and PVR (major determinants of functional capacity in PAH), patients in higher weight classes had higher dyspnea symptom burden by WHO FC. Specifically, a greater prevalence of normal/overweight patients were in FC 1 while more obese patients were in FC 3. Conclusions: Overall, in patients with PAH, higher BMI classes presented with worse FC for dyspnea, higher RA and PCW pressures, with similar PA pressures and 6MW results. Our data suggests that BMI may be an important factor that influences PAH symptoms. The impact of BMI in PAH outcomes is yet to be determined. It is possible that patients with higher BMI may exhibit more frequent comorbid conditions contributing to multifactorial symptoms of dyspnea; further study is warranted.