Diastolic blood pressure drop after standing as a clinical sign for increased mortality in older falls clinic patients.

Abstract

BACKGROUND: Orthostatic hypotension, postprandial hypotension, and carotid sinus hypersensitivity are hypotensive syndromes with high prevalence in older people. However, their pathophysiology and prognostic significance remain largely unknown. METHODS: In a retrospective cohort study of 313 consecutive patients visiting our falls outpatient clinic, we examined the clustering of orthostatic hypotension, postprandial hypotension, and carotid sinus hypersensitivity in the same patients, which might reflect a shared similar pathophysiology. The value of hypotensive syndrome presence and the degree of blood pressure decline as prognostic indicators for mortality were assessed using Cox proportional hazards analyses. RESULTS: In 313 patients (mean age 78.7 +/- 8.0 years), 168 of 309 (54%), 175 of 302 (58%), and 143 of 272 (53%) were diagnosed with orthostatic hypotension, postprandial hypotension, and sinus carotid hypersensitivity, respectively. There was no clustering of the hypotensive syndromes. During a median follow-up of 23.0 months, 58 (19%) patients died. Orthostatic hypotension, but not postprandial hypotension or carotid sinus hypersensitivity, predicted mortality [hazard ratio 1.97; 95% confidence interval (CI) 1.11-3.47]. After adjusting for age, comorbidity and other baseline characteristics, this relationship was no longer significant. However, orthostatic hypotension with severe diastolic blood pressure decline of at least 20 mmHg remained a powerful independent predictor of mortality (hazard ratio 2.50; 95% CI 1.20-5.22). CONCLUSIONS: In falls clinic patients, hypotensive syndromes did not cluster and did not independently predict mortality. However, orthostatic hypotension with severe diastolic blood pressure decline was a powerful independent predictor of mortality and might be used prognostically as an easily available cardiovascular sign of increased mortality risk.