Association between invasively measured aortic pulse pressure and orthostatic hypotension in patients undergoing invasive coronary angiography

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 20mmHg or DBP drop at least 10mmHg within 3min 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±21.3mmHg; 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.