Plasma levels of plasmin-antiplasmin-complexes are predictive for small abdominal aortic aneurysms expanding to operation-recommendable sizes

Objective: Three proteolytic systems seem involved in the aneurysmal degrad ation of the aortic wall. Plasmin is a common activator of the systems and could thus be predictive for the progression of abdominal aortic aneurysms (AAAs). Methods and Materials: In 1994, 112 of 141 male patients with AAA diagnosed through population screening (defined as 3 cm or more) were interviewed an d examined and had blood samples taken. One hundred twelve cases were scann ed annually for 1 to 5 years (mean, 2.5 years) and referred for surgery if the AAA exceeded 5 cm in diameter. A random sample of 70 of the 112 cases h ad P-plasmin-antiplasmin-complexes (PAPs), P-plasminogen, and S-elastin-pep tides (SEPs). Results. PAP was positively correlated with annual expansion rate (r = 0.39 , 0.16-0.56), persisting after adjustment for initial AAA size, SEP, age, a nd smoking. However, PAP levels did not correlate with the initial AAA size or SEP. Furthermore, PAP levels were significantly predictive for cases ex panding to operation - recommendable AAA sizes. Combined with the initial A AA size, both optimal sensitivity and specificity were 82%, increasing to 9 5% and 96%, respectively, excluding those lost to follow-up and accepting 2 min of interobserver variation. Conclusion: The progression of AAA is correlated with the PAP level, which seems to have a predictive value similar to the best serologic predictor kn own, serum-elastin-peptides.