Older patients with pulmonary arterial hypertension (PAH) may have lower pulmonary artery compliance and worse right ventricular performance compared with their younger counterparts, according to a study published in The Journal of Heart and Lung Transplantation.
With an increasingly aging population of patients with PAH, there is an urgency to better understand the relationship between age, hemodynamics, and exercise capacity to determine reliable indicators of PAH-specific disease severity in elderly patients.
In this ongoing multicenter prospective United States-based registry, The Pulmonary Hypertension Association Registry (PHAR), 769 adults with PAH (average age, 56 years; 75.8% women; 72.7% white) were enrolled and divided into 3 age groups (18−50 years: n=288); 51−65 years: n=239, and >65 years: n=242). Baseline data on sex, race, PAH diagnosis, and substance use were available for >98% of patients. Age was examined as a continuous variable in linear regression models to determine its relationship with continuous variables.
Older vs younger patients were found to be more likely to have connective tissue disease−associated PAH and less likely to have drug- or toxin-associated PAH. No differences were observed in body mass index across age groups. Each year of life was associated with a 3-millisecond lower resistance-compliance time in a linear regression analysis (95% CI, -4 to -2 milliseconds; P < .001). Additionally, each year of increased age was associated with a 3.37 meter reduction in the 6-minute walk distance test (95% CI, -3.97 to -2.76; P < .001), lower pulmonary vascular resistance (-0.06 Wood units; 95% CI, -0.09 to -0.04), and lower mean pulmonary arterial pressure (-0.21 mm Hg; 95% CI, -0.27 to -0.15). Pulmonary arterial compliance, cardiac index, right ventricular stroke work index, and percent predicted 6-minute walk distance were not found to be associated with age.
Limitations of the study include inherent biases, unavailable or missing data typical in any registry-based observational study, and the fact that left ventricular dysfunction may contribute to age-related hemodynamic differences.
“Hemodynamic variables that measure [right ventricular] function and pulsatile afterload and flow should be studied further in elderly patients with PAH to determine if they are superior to traditional variables in predicting survival and response to PAH therapies,” noted the study authors.
DesJardin JT, Kolaitis NA, Kime N, Kronmal RA, Benza Rl, Elwing JM, et al. Age-related differences in hemodynamics and functional status in pulmonary arterial hypertension: Baseline results from the Pulmonary Hypertension Association Registry (published online May 15, 2020). J Heart Lung Transplant. doi.org/10.1016/j.healun.2020.05.005