Pulmonary arterial hypertension (PAH) is historically considered a disease affecting females of childbearing potential, however, recent data suggests that majority of patients are older and postmenopausal. In order to evaluate the age distribution in our cohort, we collected clinical, hemodynamic and biomarker data sorted across tertile age ranges from prevalent PAH patients.
Data from eighty-eight PAH patients was collected from the Houston Methodist Pulmonary Hypertension Center. Clinical, hemodynamic, echocardiogram and six-minute walk data was collected, followed by an analysis of biomarker levels from peripheral blood samples taken once from each patient. All patients were then stratified into tertiles by age (18-40 years, ≤41-54 years, ≤54-78 years). A one-way analysis of variance was used to identify important statistical significances, determined as p-value <0.05.
Age of patients in this cohort was 47±15 years (mean±SD), and 90% of the patients were female. Duration of disease since diagnosis (p=0.005), and concurrently use of beta-blockers (p=0.018) increased with age. There was a trend towards a lower pulse rate with age (p=0.057). Contrary to published data, in our cohort, N-terminal propeptide of type III procollagen levels decreased with age (p=0.007). The echocardiogram data suggested that both cardiac output and cardiac index were lower in the younger age group as compared to the older PAH patients (p=0.019 and 0.020 respectively). Similarly, diffusing capacity of the lung for carbon monoxide decreased with age (p=0.001). Interestingly, there was no significant difference in mortality across the tertiles.
In our cohort, hemodynamics, biomarkers and echocardiogram data differed across age groups though the overall long-term survival was not different. This data suggested that there may be a survival bias for patients with milder disease. Further studies are needed to investigate these findings.