Relationships between subendocardial perfusion impairment, arterial stiffness and orthostatic hypotension in hospitalized elderly individuals

Background: Orthostatic hypotension is an independent risk factor for cardiovascular morbidity and mortality. Arterial stiffness has been shown to be a pathophysiological mechanism linking orthostatic hypotension and increased cardiovascular risk. This study aims to evaluate the relationship between arterial stiffness, orthostatic hypotension and subendocardial viability ratio (SEVR) and moreover to identify the main predictors of orthostatic hypotension, carotid-femoral pulse wave velocity (PWV-cf) and SEVR. Methods: Seventy-five patients were enrolled (mean age 82.95 +/- 6.45) in Verona's AOUI Geriatric ward. They underwent blood pressure, heart rate, body weight measurements and also comorbidity, arterial stiffness (PWV-cf measured by applanation tonometry), SEVR and biochemical indexes. Results: Prevalence of orthostatic hypotension was 46.6%. Even after adjustment for age, sex, glomerular filtration rate and mean arterial pressure, SEVR values corrected for arterial oxygen and haemoglobin content were statistically lower in orthostatic hypotension patients (P = 0.05) and PWV-cf values were statistically higher in orthostatic hypotension individuals (P = 0.042). In a binary logistic regression, PWV-cf was the only significant predictor of orthostatic hypotension (odds ratio 1.123; P = 0.039; confidence interval = 1.006--1.17). In a backward logistic regression model sex, creatinine clearance and orthostatic hypotension were significant predictors of SEVR corrected for O-2 content. Mean arterial pressure, creatinine clearance and orthostatic hypotension were significant predictors of PWV-cf. Conclusion: This study shows that orthostatic hypotension is related to increased arterial stiffness, confirming its higher prevalence in elderly patients. Orthostatic hypotension was also associated with reduced values of corrected SEVR, showing a relevant consequence of orthostatic hypotension on subendocardial perfusion impairment.