Pulmonary Blood Volume Among Older Adults in the Community: The MESA Lung Study

Abstract

Background: The pulmonary vasculature is essential for gas exchange and impacts both pulmonary and cardiac function. However, it is difficult to assess and its characteristics in the general population are unknown. We measured pulmonary blood volume (PBV) noninvasively using contrast enhanced, dual-energy computed tomography to evaluate its relationship to age and symptoms among older adults in the community. Methods: The MESA (Multi-Ethnic Study of Atherosclerosis) is an ongoing community-based, multicenter cohort. All participants attending the most recent MESA exam were selected for contrast enhanced dual-energy computed tomography except those with estimated glomerular filtration rate <60 mL/min per 1.73 m 2 . PBV was calculated by material decomposition of dual-energy computed tomography images. Multivariable models included age, sex, race/ethnicity, education, height, weight, smoking status, pack-years, and scanner model. Results: The mean age of the 727 participants was 71 (range 59–94) years, and 55% were male. The race/ethnicity distribution was 41% White, 29% Black, 17% Hispanic, and 13% Asian. The mean±SD PBV in the youngest age quintile was 547±180 versus 433±194 mL in the oldest quintile ( P <0.001), with an approximately linear decrement of 50 mL per 10 years of age ([95% CI, 32–67]; P <0.001). Findings were similar with multivariable adjustment. Lower PBV was associated independently with a greater dyspnea after a 6-minute walk ( P =0.04) and greater composite dyspnea symptom scores ( P =0.02). Greater PBV was also associated with greater height, weight, lung volume, Hispanic race/ethnicity, and nonsmoking history. Conclusions: Pulmonary blood volume was substantially lower with advanced age and was associated independently with greater symptoms scores in the elderly.

Functional gas exchange measures on 129Xe MRI and spectroscopy are associated with age, sex, and BMI in healthy subjects

“…The increased RBC amplitude oscillations with age may be caused in part by reduced pulmonary vascular volume, a known consequence of normal aging ( 31 ). This type of characterization may be useful to incorporate into models of pulmonary hypertension ( 19 ) or other studies that use xenon hemodynamics as an indicator of cardiovascular abnormalities.…”

Abnormal heart rate responses to exercise in non-severe COPD: relationship with pulmonary vascular volume and ventilatory efficiency

“…In this subset of individuals, endothelial injury and pulmonary vascular remodelling may occur before developing airflow obstruction or emphysema, the so-called “pulmonary vascular phenotype” [ 33 ]. Despite poorer prognosis due to early pulmonary vascular damage [ 34 ], this phenotype has been overlooked in most researchand clinical practice. By supplementing cardiac performance for this subset, our finding have stressed that they may be exposed to a higher risk of cardiac dysfunction, appealing more clinical attention and directed research.…”

Elderly Patients with Idiopathic Pulmonary Hypertension: Clinical Characteristics, Survival, and Risk Stratification in a Single-Center Prospective Registry

“…Another issue is the PVR cut-off for the pulmonary vascular disease definition in elderly patients [52][53][54]. PVR was similar in the young and elderly IPAH patients in our study (13.8 ± 6.86 and 12.6 ± 5.27 WU, respectively) and is comparable with the PVR value in young typical IPAH patients in the NIH, ASPIRE, REVEAL, and French registers, whereas PVR in the COMPERA and Swiss registries is lower (9.6 ± 5.5; 8.5 ± 5.2 WU, respectively) [9,48,49].…”

“…Taking into account the number of reasons for pulmonary vasculature and heart remodeling with aging [52,53,62], IPAH identification remains an exciting diagnostic dilemma. A sophisticated diagnostic workup with hemodynamic testing, weighting of hemodynamic parameters and clinical presentation, comorbidity, right and left heart remodeling, and laboratory markers are warranted in the elderly population for true IPAH diagnosis [61,63].…”