Delayed versus classic orthostatic hypotension: clinical and prognostic implications.

Purpose: Orthostatic hypotension (OH) is a common disorder, especially among hospitalised patients. Classic OH is defined as occurring 3 or less minutes of orthostatic stress, and delayed OH as occurring after 3 min of stress. We aimed to compare clinical characteristics and prognosis between inpatients with classic vs. delayed OH. Methods: We performed a retrospective analysis of data from 358 inpatients, aged >= 60 years, who were evaluated for the occurrence of OH at the initial phase of ambulation in four previous prospective studies in our department. Demographic, clinical and prognostic data were compared between patients with (n = 191) vs. without (n = 167) OH, classic (n = 138) vs. delayed (n = 53) OH and seated (n = 115) vs. standing (n = 76) OH. Results: Demographic characteristics, duration of bed rest, the main reasons for admission and the use of offending medications were comparable between the delayed and classic OH groups. Mean maximal postural diastolic (p < .001) and systolic (p = .063) blood pressure falls were higher among patients with classic v. delayed OH. No statistically significant difference between the patients with classic and delayed OH were observed in the occurrence of OH-related symptoms (62.3 vs. 69.8%, p = .42). During a median follow-up of 5.5 years, no statistically significant differences in survival were observed between patients with vs. without OH (p = .14), classic vs. delayed OH (p = .68) and seated vs. standing OH (p = .067). On multivariate analysis, these variables remained not significantly associated with decreased survival. Conclusions: Among inpatients, delayed OH is associated with a lesser magnitude of orthostatic blood pressure fall than classic OH. However, rates of symptomatic OH and long-term mortality were comparable between the groups. Thus, among hospitalised patients, delayed OH should be considered as posing the same severity as classic OH.