Orthostatic Hypotension and Risk of Venous Thromboembolism in 2 Cohort Studies

BACKGROUND Although venous stasis is a risk factor for venous thromboembolism (VTE) and orthostatic hypotension (OH) can cause venous stasis, to our knowledge no study has examined the relationship between OH and VTE risk. We sought to quantify the association between OH and VTE (deep vein thrombosis or pulmonary embolism) using data from 2 large, prospective cohort studies: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) Study. We hypothesized that OH was positively associated with incident VTE. METHODS We measured OH-defined as a drop in systolic blood pressure (SBP) of at least 20 mm Hg or diastolic blood pressure (DBP) of at least 10mm Hg within 3 minutes of standing-in participants aged 45-64 years in ARIC (n = 12,480) and >= 65 years in CHS (n = 5,027) at baseline visits (1987-1989 in ARIC; 1989-1990 and 1992-1993 in CHS), and followed participants for incident VTE (n = 568 in ARIC through 2011 and n = 148 in CHS through 2001). We calculated adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for incident VTE in relation to OH status. RESULTS In CHS, there was a positive association between OH status and incident VTE (HR for VTE = 1.74 (95% CI: 1.20-2.51)). In contrast, there was no association between OH and VTE in the ARIC study (HR for VTE = 0.97 (95% CI: 0.70-1.33)). CONCLUSIONS Community-dwelling older adults with OH had a moderately increased risk of VTE. These results were not seen in a population-based middle-aged cohort.