Objective: To investigate the association between peripherally measured arterial compliance and cardiovascular and total mortality in an elderly cohort.
Background: There is limited evidence that systemic indices of elasticity and stiffness in the carotid and femoral arteries can predict incident cardiovascular disease (CVD) events. Little is known about the associations between systemic arterial compliance and CVD events.
Methods: Between 1997 and 1999, 849 community dwelling participants in the Rancho Bernardo Study (mean age 74, 39% male, 4.2% with type 2 diabetes) underwent noninvasive pulse wave measurements. Systemic and brachial artery compliance were estimated using the PulseMetric device applying an algorithm previously validated by angiography. Data on cardiovascular risk factors and fasting blood samples were obtained at the same visit as the compliance measurements, as well as at a follow-up visit conducted within one year. CVD and overall mortality were recorded through January 2013. Kaplan-Meier survival curves for quartiles of systemic and brachial artery compliance were constructed. Cox proportional hazards models were used to examine the associations of systemic and brachial artery compliance with all-cause and CVD mortality. Multivariable models were used to assess interactions and to estimate the role of potential confounders. Stratified models were constructed when interactions of p<0.15 were found.
Results: During a mean follow-up of 10 years (SD=3.9), 324 deaths occurred, 114 of which were attributed to CVD. Kaplan-Meier curves suggested an increasing probability for survival with increasing quartiles of arterial systemic compliance (p < 0.001). In the fully adjusted Cox proportional hazard model, a 1-SD increment in systemic compliance was associated with a 39% lower risk of mortality (HR = 0.61, 95% CI: 0.47-0.79) and a 37% lower risk for CVD mortality (HR = 0.63, 95% CI 0.41-0.96). A significant interaction by sex was found (p=0.01). Specifically, among women, the association between systemic arterial compliance and mortality was stronger in the fully adjusted model (HR = 0.59, 95% CI 0.42-0.83) than in men (HR = 0.70, 95% CI 0.50-0.96). Similar sex-specific associations were found for CVD mortality, but those were not statistically significant (HR in women = 0.60, 95% CI 0.38-1.08; HR in men = 0.64, 95% CI 0.35-1.17). Brachial artery compliance was not significantly associated with the considered events (all-cause mortality: HR 0.86, CI 0.66-1.14; CVD mortality: HR 0.99, CI 0.59-1.63).
Conclusions: In an elderly cohort, systemic arterial compliance, but not brachial artery compliance, was significantly associated with total and CVD mortality, and the relationships were stronger in women. Non-invasive measurement of systemic compliance may be useful in predicting mortality risk in older, community-dwelling adults.