1Thoraxklinik - Heidelberg gGmbH Pneumologie und Beatmungsmedizin / Zentrum für Pulmonale Hypertonie Heidelberg, Deutschland; 2Universitätsklinikum Heidelberg Thoraxklinik Heidelberg, Deutschland; 3University Federico II of Naples Department of Translational Medical Sciences 80131, Italien
Background: From clinical experience, obesity can complicate and aggravate symptoms and progression of right heart failure in patients with pulmonary arterial hypertension (PAH). However, there is only few data on clinical and hemodynamic effects of overweight in this population. Therefore, we sought to investigate the influence of body weight on symptoms and right heart function in PAH assessed by right heart catheter.
Methods: In this cross-sectional study with survival follow-up (mean follow-up 3.1 ± 2.6 years, median 2.7 years), clinical measures such as WHO-functional class and invasively measured hemodynamic parameters at initial diagnosis of PAH were compared between different body-mass-index (BMI) groups.
Results: Out of 2058 datasets, 755 patients with PAH (62.5% female) were eligible for the study (65 ± 15 years, 44.9% idiopathic PAH, 64.8% WHO functional class III or IV). Out of them 15 patients (1.99%) were underweight (BMI <18), 248 (32.85%) patients had a normal weight (BMI 18.5-25), 256 (33.91%) were overweight (BMI >25-30) and 236 patients (31.26%) were classified as obese (BMI >30). Cardiac output (CO) significantly differed between BMI groups (Figure 1). A significant but weak correlation could be shown for CO and BMI (p<0.0001, R=0.268). Men showed a higher CO than women (p=0.004), with less distinct differences in groups with higher BMI. There was no association of hyperdynamic status und elevated BMI. In multivariable age-adjusted survival analysis, BMI-status, sex and right ventricular function, but not CO and cardiac index, were identified as independent predictors of survival.
Conclusion: In this study cohort, a weak association could be found between BMI-status and CO. Hyperdynamic CO was more frequent in underweight patients. BMI-status, sex and right ventricular function were superior to predict survival compared to CO and cardiac index. Further studies are needed to validate the results.