Grant: Travel Awards - Institute Community Support

Background: Orthostatic hypotension (OH) is an important clinical finding when evaluating syncope and falls. OH is diagnosed based on a supine-to-standing test, however this test can be impractical in settings like the outpatient clinic where time and space are limited. An alternative is a sit-to-stand procedure; this test induces a milder orthostatic stress making conventional diagnostic cut-offs for OH difficult to reach. This study aimed to identify optimal blood pressure (BP) cut-offs to diagnose OH during sit-to-stand. Methods: This study was made up of patients and healthy subjects who presented to the Vanderbilt University Autonomic Dysfunction Center. BP was measured while supine, seated, and standing (for 5 minutes). BP change was calculated from 1) supine-to-standing and 2) seated-to-standing. OH was diagnosed by a supine-to-standing systolic BP drop greater than 20 mmHg or a diastolic BP drop greater than 10 mmHg. Receiver operator characteristic curves identified optimal sit-to-stand cut-offs and the area under the curve was calculated. Results: Amongst the 994 subjects, more had systolic OH (n=404[41%]) than diastolic OH (n=349[35%]). We found that a sit-to stand systolic BP drop greater than 15 mmHg had optimal test characteristics (sensitivity=79%; specificity=89%; positive predictive value=83%; negative predictive value=86%), as did a diastolic BP drop greater than 7 mmHg (sensitivity=85%; specificity=88%; positive predictive value=79%; negative predictive value=91%). Conclusions: A sit-to-stand maneuver with lower diagnostic cut-offs for OH provides a simple OH screening test. This may be of utility in multiple clinical environments where testing could quickly be done upon patient arrival at triage or while in the clinic waiting room.