1Thoraxklinik - Heidelberg gGmbH Pneumologie und Beatmungsmedizin / Zentrum für Pulmonale Hypertonie Heidelberg, Deutschland; 2University Federico II of Naples Department of Translational Medical Sciences 80131, Italien; 3University of Sheffield Sheffield Pulmonary Vascular Disease Unit; Royal Hallamshire Hospital Sheffield, Großbritannien
Background: The objective of the study was to investigate sex-differences in right heart size of patients with pulmonary arterial hypertension (PAH) and in ESC/ERS risk stratification of right heart size.
Methods: In this retrospective cross-sectional study with survival follow-up, routine clinical examinations from initial diagnosis of PAH were analysed. Right atrial (RA) and right ventricular (RV) area were measured by transthoracic echocardiography. Prognostic power was gained by comparing follow-up data from the patients with different thresholds for the RA area from the ESC/ERS risk stratification and sex-specific thresholds using multivariable analysis.
Results: Of 748 PAH patients (mean age of 65 ± 15 years, 63.40% female), men had significantly larger right heart size than women (RA area 21.76 ± 7.64 cm2 vs. 17.65 ± 6.82 cm2, p<0.001; RV area 24.02 ± 7.15 cm2 vs. 18.41 ± 5.75 cm2, p<0.001). This difference was consistent throughout all WHO functional classes (WHO-FC) and cardiac index (CI) risk groups (Figure 1), except for the RA area in CI high risk group and WHO-FC IV. Men presented with a worse prognosis compared to women throughout all RA area risk groups according to ESC/ERS risk stratification and thresholds of RA area indexed to body surface area (BSA). In multivariable analysis, indexed values showed more pronounced differences for age-adjusted survival analysis compared to ESC/ERS risk stratification thresholds.
Conclusions: This is the first study presenting distribution of right heart size according to sex in patients with pulmonary hypertension with data indicating that sex-adjustment might be considered for risk stratification thresholds for RA area. Indexed values by body surface area might be an option to adjust for body size. Further studies with larger sample sizes are needed to define sex-specific thresholds of right heart size.