Sex differences in the prevalence and survival of pulmonary hypertension in obstructive hypertrophic cardiomyopathy following septal myectomy

Background: Pulmonary hypertension (PH) and female have been linked to a worse survival in patients with obstructive hypertrophic cardiomyopathy (oHCM). However, female patients with PH exhibited a better prognosis than males. Herein, we investigated sex differences in the prevalence and survival of pH in oHCM following septal myectomy. Methods: We consecutively enrolled 1491 patients diagnosed with oHCM. PH was defined as a pulmonary artery systolic pressure (PASP) > 36 mm Hg. Results: Females were older, more likely to experience chest pain and NYHA class III/IV symptoms, and had a higher prevalence of PH (37.6 % vs. 19.9 %, p < 0.001) than males. Multivariable analysis showed that female was an independent risk for PH (OR 2.3, 95 % CI: 1.70-3.11, p < 0.001) though the PASP was comparable between males and females (44.93 ± 10.87 vs. 44.74 ± 9.72 mm Hg, p = 0.856). Over a median follow-up of 36 months [IQR 23.5-52.5 months), 28 deaths and 189 composite endpoints were observed. Kaplan-Meier analysis showed a higher cumulative incidence of death (p = 0.015) and composite endpoints (p < 0.001) in patients with PH, and Cox regression analysis revealed that PH (HR 1.78, 95 % CI: 1.30-2.45, p < 0.001) and female (HR 1.39, 95 % CI: 1.02-1.90, p = 0.038) were independently associated with composite endpoints. However, no significant survival differences were found between males and females within the PH subgroup. Conclusions: Female was independently associated with higher prevalence but not severity of PH. Although PH and female were independently associated with worse survival, no survival difference was found between males and females in the PH subgroup.