Association of Stroke with Ambulatory Arterial Stiffness Index (AASI) in Hypertensive Patients

The ambulatory arterial stiffness index (AASI) predicted stroke in hypertensive patients and in the general populations. However, no similar data was available in Chinese. In the present study, we sought confirmation that Chinese hypertensive patients with a history of stroke would have an elevated AASI. We retrospectively analyzed the data of 156 hypertensive outpatients (60.9 % men; mean age, 61.5 years) and 582 inpatients (63.6 % men; 58.6 years) of the Hypertension Department at Ruijin Hospital in Shanghai, China. The AASI was calculated as 1 - the regression slope of diastolic blood pressure (DBP) on systolic blood pressure (SBP) in individual 24-h ambulatory recordings. With adjustment applied for sex, age, body mass index (BMI), the 24-h mean arterial pressure, and other cardiovascular risk factors, AASI was higher in patients with a history of stroke than in patients without stroke in both outpatient (0.51 ± 0.02 vs. 0.47 ± 0.01; P = 0.050) and inpatient (0.46 ± 0.01 vs. 0.44 ± 0.01; P = 0.031) cohorts. The odds ratio (OR) for a history of stroke associated with a 1-SD increase in AASI was 1.63 (95% confidence interval (CI), 1.01-2.62; P = 0.046) in outpatients, 1.32 (1.01-1.74; P = 0.046) in inpatients, and 1.30 (1.05-1.62; P = 0.018) in two patient cohorts combined (n = 738) after multivariate adjustment including the night-to-day ratio of SBP. Our findings suggest that Chinese hypertensive patients with a history of stroke, compared to those without such history, have stiffer arteries, as exemplified by a higher AASI.