Echocardiographic estimates of pulmonary artery acceleration time and mortality risk in older adults.
Abstract
Background
Pulmonary artery acceleration time (PAAT) is an echocardiographic measure associated with pulmonary artery pressure. Although reduced PAAT has been linked to pulmonary hypertension and adverse outcomes in selected patient populations, less is known about its prognostic significance in community-dwelling older adults, which was the focus of the present study.
Methods
Using baseline echocardiographic PAAT measurements, we categorized 2758 participants in the Cardiovascular Health Study into PAAT >130 ms (N = 758), 100-130 ms (N = 1089), and <100 ms (N = 911). Cox regression models were used to estimate associations with mortality (reference, PAAT >130 ms), and restricted cubic spline analyses were used to assess nonlinearity of the associations (reference, PAAT 130 ms), during a median follow-up of 13.4 years.
Results
All-cause mortality occurred in 75.2%, 82.9%, and 85.5% of participants with PAAT >130 ms, 100-130 ms, and <100 ms, respectively. Corresponding age-sex-race-adjusted HRs (95% CIs) were 1.00, 1.11 (0.99-1.23) and 1.20 (1.08-1.34). Associations were attenuated primarily by adjustment for World Health Organization Group 2 (cardiac) but not Group 3 (pulmonary) pulmonary hypertension physiology and by adjustment for subclinical biomarkers and were no longer significant in fully adjusted models. Associations and attenuations were stronger for cardiovascular mortality than non-cardiovascular mortality. Restricted cubic spline analyses demonstrated no significant nonlinearity in age-sex-race-adjusted HRs for total mortality, which increased progressively at PAAT values below 130 ms.
Conclusions
Lower PAAT is associated with higher risks of death in community-dwelling older adults. The association appears to be explained largely by cardiovascular disease and systemic health status rather than pulmonary disease alone. PAAT may serve as an integrated marker of cardiopulmonary and systemic vulnerability in older adults.