Resistive and pulsatile arterial hemodynamics and cardiovascular events: The multiethnic study of atherosclerosis

Background-Arterial blood pressure is dependent on interactions between the heart and arteries. Resistive and pulsatile components of arterial load can be assessed by systemic vascular resistance (SVR, a microvascular property) and the ratio of stroke volume to pulse pressure (a surrogate of total arterial compliance, TAC), respectively. The relationship between arterial function and cardiovascular events in populations without cardiovascular disease is unknown. Methods and Results-We studied 4806 adults enrolled in the Multi-Ethnic Study of Atherosclerosis who were free of clinical cardiovascular disease at baseline. SVR and stroke volume/pulse pressure (SV/PP) were derived by sphygmomanometry and magnetic resonance imaging. The relationship between these measures of arterial function and incident cardiovascular events was assessed using Cox regression. With a mean follow-up of 7.5 years, cardiovascular events occurred in 358 participants (7.4%). There was no relationship between SVR and subsequent cardiovascular events. However, increased stroke volume/pulse pressure was associated with reduced event rate in unadjusted (hazard ratio=0.67, 95% CI=0.58 to 0.77, P<0.001) and analyses that adjusted for multiple confounders (HR=0.75; 95% CI=0.62 to 0.90; P<0.001). Conclusions-Greater total arterial compliance, manifest by higher stroke volume/pulse pressure is associated with a reduced incidence of subsequent CVE. In contrast, SVR was not independently associated with CVE in subjects free of overt cardiovascular disease at baseline. These findings support the concept that alternations in the large conduit vessels, rather than changes in microvascular resistance, are primarily related to incident cardiovascular disease.