Sex-specific differences in echocardiographic parameters of risk stratification in pulmonary arterial hypertension

<bold>Background:</bold> The objective of the study was to investigate sex differences in echocardiographic ESC/ERS risk stratification parameters and their impact on survival estimation in patients with pulmonary arterial hypertension (PAH). <bold>Methods:</bold> In this retrospective, cross-sectional study with a mean follow-up time of 3.2 ± 2.65 years we assessed invasive and non-invasive clinical parameters including right atrial (RA), right ventricular (RV) area and tricuspid annular plane systolic excursion (TAPSE) divided by systolic pulmonary arterial pressure (sPAP). Different thresholds for the ESC/ERS risk stratification and sex-specific thresholds were compared by multivariable analysis. <bold>Results:</bold> Of 748 PAH patients (mean age of 65 ± 15 years, 63 % 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, except for the RA area in CI high risk group and WHO-FC IV. At multivariable analysis, indexed values showed more pronounced differences for age-adjusted survival analysis compared to ESC/ERS risk stratification thresholds. TAPSE/sPAP showed no significant sex differences which makes this parameter a robust prognostic predictor. <bold>Conclusions:</bold> This is the first study showing sex differences in right heart size obtained by echocardiography in PAH. For risk stratification RA-area should be used as indexed values corrected for body surface area. In contrast, TAPSE/sPAP values were not sex-dependent and were a robust prognostic predictor in PAH.