Sex Differences in Pulmonary Hypertension and Associated Right Ventricular Dysfunction

Prior studies have established the impact of sex differences on pulmonary arterial hypertension (PAH). However, it remains unclear whether these sex differences extend to other hemodynamic subtypes of pulmonary hypertension (PH). We examined sex differences in PH and hemodynamic PH subtypes in a hospital-based cohort of individuals who underwent right heart catheterization (RHC) between 2005 and 2016. We utilized multivariable linear regression to assess the association of sex with hemodynamic indices of right ventricle (RV) function (PA pulsatility index [PAPi], RV stroke work index [RVSWI], and right atrial: pulmonary capillary wedge pressure ratio [RA:PCWP]). We then used Cox regression models to examine the association between sex and clinical outcomes among those with PH. Among 5,208 individuals with PH (mean age 64 years, 39% women), there was no significant sex difference in prevalence of PH. However, when stratified by PH subtype, 31% of women versus 22% of men had precapillary (p <0.001), 39% versus 51% had postcapillary (p <0.001), and 30% versus 27% had mixed PH (p = 0.03). Female sex was associated with better RV function by hemodynamic indices, including higher PAPi and RVSWI (p <0.001 for both). Over 6.3 years of follow-up, female sex was associated with a lower risk of heart failure hospitalization (HR 0.83, 95% CI 0.74 to 0.91, p <0.001). In conclusion, across a broad hospital-based sample, more women had precapillary and more men had postcapillary PH. Compared with men, women with PH had better hemodynamic indices of RV function and a lower risk of heart failure (HF) hospitalization.