Orthostatic hypotension in hospitalized hypertensive patients admitted to internal medicine wards: rationale and design of the HYP-OP Study

Orthostatic hypotension (OH) is common yet frequently underrecognized in older adults and in patients with arterial hypertension (AH). OH is associated with falls, cardiovascular (CV) events, cognitive decline, and mortality. Despite guideline recommendations, orthostatic blood pressure (BP) measurement is not systematically performed in internal medicine wards. The objective of the study protocol is to estimate the prevalence of OH in hypertensive patients hospitalized in internal medicine units, to identify clinical factors independently associated with OH, and to evaluate the prognostic impact of OH on long-term outcomes. The HYP-OP Study is a national, multicenter, prospective, observational cohort study conducted in approximately 30 internal medicine units in Italy. Overall, 1000 consecutive adult patients with known hypertension or newly diagnosed AH during hospitalization were enrolled. BP and heart rate were measured after at least 5 minutes of rest in the seated position and again after standing for 1 and 3 minutes according to a standardized protocol. During the hospitalization, demographic, clinical, laboratory, cognitive (Mini-Mental State Examination), frailty/physical performance (Short Physical Performance Battery), comorbidity burden (Charlson Comorbidity Index), and pharmacological data were collected. Follow-up was scheduled at 6, 12, 24, and 36 months after discharge to assess falls, major CV events (stroke, transient ischemic attack, myocardial infarction, arrhythmias), and all-cause mortality. The primary endpoint is the prevalence of OH and the identification, through multivariate analysis, of clinical factors independently associated with OH. Secondary analyses will assess the prognostic value of OH for subsequent falls, major CV events, and mortality. The HYP-OP Study will provide contemporary, real-world data on the burden, clinical correlates, and prognostic significance of OH in hypertensive patients hospitalized in internal medicine wards and may support more consistent implementation of orthostatic BP assessment in routine practice.