OBJECTIVE Underlying pathophysiology of orthostatic hypotension has been poorly understood. We hypothesized that aortic pulse pressure (APP) reflecting aortic stiffness may be involved in the development of orthostatic hypotension.

METHODS A total of 200 patients (age 64.3 ± 10.9 years, 62.5% men) who underwent invasive coronary angiography (ICA) were prospectively recruited. Orthostatic hypotension was defined as SBP drop at least 20 mmHg or DBP drop at least 10 mmHg within 3 min of the standing position compared with the supine position. Hemodynamic parameters were measured at the ascending aorta using a pig-tail catheter immediately before ICA. APP was calculated as a difference between the aortic peak systolic pressure and the end-diastolic pressure.

RESULTS A total of 156 patients (78.0%) had obstructive coronary artery disease on ICA. Orthostatic hypotension was present in 58 patients (29.0%). Diabetes mellitus was more prevalent in patients with orthostatic hypotension than those without (48.3% vs. 23.2%; P < 0.001). Other clinical parameters including age, cardiovascular risk factors, laboratory findings and concomitant medications were not different between patients with and without orthostatic hypotension (P > 0.05 for each). In hemodynamic parameters, APP was higher in patients with orthostatic hypotension than those without (78.4 ± 25.8 vs. 68.3 ± 21.3 mmHg; P = 0.005). Higher APP was significantly associated with the presence of orthostatic hypotension even after controlling for potential confounders (odds ratio, 2.99; 95% confidence interval 1.15-7.78; P = 0.025).

CONCLUSION In patients undergoing ICA, APP was associated with increased risk of orthostatic hypotension. Central aortic stiffness may play a role in the development of orthostatic hypotension.