Plasma Tissue Plasminogen Activator and Abdominal Aortic Aneurysm Presence: A Systematic Review and Meta-analysis

Abstract

To summarize the present evidence for an association between circulating tissue plasminogen activator (tPA) levels and abdominal aortic aneurysm (AAA) presence, we performed a systematic review and meta-analysis of case-control studies that compared plasma tPA levels between patients with AAA and subjects without AAA. MEDLINE was searched to identify all case-control studies that compared plasma tPA levels between patients with AAA and subjects without AAA. For each study, data regarding plasma tPA levels in both the AAA and control groups were used to generate standardized mean differences and 95% confidence intervals. Study-specific estimates were combined using inverse variance-weighted average of logarithmic standardized mean differences in both fixed- and random-effects models. Our search identified five eligible case-control studies, including data on 234 patients with AAA and 459 subjects without AAA. Pooled analysis of the five studies demonstrated nonsignificantly higher plasma tPA levels in the AAA group than those in the control group in fixed-effect models (standardized mean differences = 0.07; 95% confidence interval = -0.09-0.24; p = 0.40). There was minimal study heterogeneity of results (p = 0.05) and no evidence of significant publication bias (p = 0.3272). The results of our analysis suggest that plasma tPA levels may not be higher in patients with AAA than those in subjects without AAA. Higher plasma tPA levels may not be associated with AAA presence.