Association of Hypertension with Abdominal Aortic Aneurysm Expansion

Abstract

Background: Hypertension is positively associated with abdominal aortic aneurysm (AAA) presence, which supports a hypothesis that hypertension may also be positively associated with AAA expansion. To determine whether hypertension is associated with AAA expansion, we reviewed currently available studies with a systematic literature search and meta-analytic estimate.

Methods: Databases including MEDLINE and EMBASE were searched through July 2015 using Web-based search engines (PubMed and OVID). Studies considered for inclusion met the following criteria: the study population was AAA patients with and without hypertension, and outcomes included data regarding AAA expansion. For each study, expansion rates in both the hypertensive and nonhypertensive groups were used to generate standardized mean differences (SMDs) and 95% confidence intervals (CIs).

Results: Of 614 potentially relevant publications screened initially, we identified 20 eligible studies including data on 6,619 AAA patients. No individual study indicated a statistically significant (positive or negative) association of hypertension with AAA expansion rates. A pooled analysis of all the 20 studies demonstrated that hypertension was not associated with AAA expansion rates in the fixed-effect model (SMD 0.03, 95% CI -0.01 to 0.17, P = 0.19). There was no evidence of significant publication bias.

Conclusions: Hypertension is not associated with AAA expansion. Further investigations would be required to elucidate why hypertension is not associated with AAA expansion despite its positive association with AAA presence.