Impact of age on pulmonary artery systolic pressures at rest and with exercise

Abstract

Aim: It is not well known if advancing age influences normal rest or exercise pulmonary artery pressures. The purpose of the study was to evaluate the association of increasing age with measurements of pulmonary artery systolic pressure at rest and with exercise.

Subjects and methods: A total of 467 adults without cardiopulmonary disease and normal exercise capacity (age range: 18-85 years) underwent symptom-limited treadmill exercise testing with Doppler measurement of rest and exercise pulmonary artery systolic pressure.

Results: There was a progressive increase in rest and exercise pulmonary artery pressures with increasing age. Pulmonary artery systolic pressures at rest and with exercise were 25±5mmHg and 33±9mmHg, respectively, in those <40 years, and 30±5mmHg and 41±12mmHg, respectively, in those ≥70 years. While elevated left-sided cardiac filling pressures were excluded by protocol design, markers of arterial stiffness associated with the age-dependent effects on pulmonary pressures.

Conclusion: These data demonstrate that in echocardiographically normal adults, pulmonary artery systolic pressure increases with advancing age. This increase is seen at rest and with exercise. These increases in pulmonary pressure occur in association with decreasing transpulmonary flow and increases in systemic pulse pressure, suggesting that age-associated blood vessel stiffening may contribute to these differences in pulmonary artery systolic pressure.

Keywords: pulmonary artery systolic pressure; stress echocardiography.

Figure 1

Representative 2D and Doppler examples. Stroke volume was calculated from the LV inflow as the product of mitral valve area derived from the diameter at the level of the mitral valve tips from the apical four chamber view (A) and the LV inflow time velocity integral as measured by pulsed-wave Doppler of the mitral inflow at the level of the mitral valve tips from the apical four chamber view (B). The ratio of early mitral inflow peak velocity (B) to that of the early peak tissue velocity of the medial mitral annulus (C) was used as an estimate of LV filling pressure. The PA systolic pressure was calculated in standard fashion from the peak tricuspid regurgitant velocity (D).

Figure 2

Age-dependent changes in pulmonary artery systolic pressure with exercise. There is a progressive rise in pulmonary artery systolic pressure at rest and with exercise with advancing age. Curves were fitted to the data using linear regression analysis. Dashed lines indicate the upper and lower 95% confidence limits for the mean values.

Figure 3

Age-dependent changes in pulmonary artery systolic pressure adjusted for cardiac index with exercise. Progressive rise in pulmonary artery systolic pressure at rest and with exercise persists with advancing age after adjusting for transpulmonary flow (cardiac index). Curves were fitted to the data using linear regression analysis. Dashed lines indicate the upper and lower 95% confidence limits for the mean values.

Figure 4

Association between resting pulmonary artery systolic pressure and systemic pulse pressure. There is a rise in pulmonary artery systolic pressure at rest as systemic pulse pressure rises.