Morbidity and mortality related to orthostatic hypotension: results of a meta-analysis of non-randomized observational studies

Abstract

Purpose: The role of orthostatic hypotension (OH) as a risk factor for cardiovascular morbidity and mortality is still controversial. We aimed at an accurate estimate of this relationship with a meta-analysis of patients pooled from epidemiological studies.Methods: We systematically searched PubMed for epidemiological studies published in 1966-2012 and examining the association between OH and major acute cardiac and cerebral events (MACCE). Search terms included "orthostatic hypotension" AND "coronary heart disease", "stroke", "mortality" OR "heart failure". We used random-effects models to estimate summary Odds Ratios (OR) and 95% Confidence Intervals (95% CI) for all-cause mortality, coronary heart disease (CHD), stroke and heart failure (HF), assessed at the longest available follow-up. We also performed subgroup analyses stratified by age.Results: We identified a total of 9 studies, including a total of 56,386 patients, with a median follow-up of 6.4 years. Compared with the OH-negative status, an OH-positive condition was associated with a significantly increased risk of all-cause mortality (OR: 1.81, 95% CI 1.37-2.38), CHD (OR: 1.46, 95% CI 1.20-1.78) and HF (OR: 2.18, 95% CI 1.18-4.00). OH was also associated with a trend toward increased risk of stroke (OR: 1.63, 95% CI 0.98-2.70). When analyzed according to age, pooled estimates of OR for all-cause mortality were 2.44 (95% CI 1.44-4.13) for patients younger than 65 years vs 1.42 (95% CI 0.99-2.04) for the older subgroup.View larger version: In this page In a new window Download as PowerPoint Slide Odds Ratio and 95% CI of mortalityConclusions: OH confers an increased risk of death, CHD and HF, but did not influence stroke incidence as compared with its absence. The association between OH and mortality was stronger among younger adults. OH should be enlisted among the risk factors for MACCE.