Summary
Plasmin-α2-antiplasmin complex (PAP) is an index of recent fibrinolytic activity. We examined
PAP levels in patients with atrial fibrillation (AF) to determine whether these levels
are correlated with clinical characteristics associated with stroke risk. We obtained
blood for measurement of PAP in a non-random sample of 586 patients with AF on entering
the Stroke Prevention in Atrial Fibrillation III Study. PAP levels were measured with
an ELISA assay. PAP values were transformed with a natural logarithm (PAPln) prior to all analyses. Older age, female gender, recent congestive heart failure,
decreasing fractional shortening, recent onset of AF, and coronary artery disease
were each univariately associated with higher levels of PAP (all p <0.05, two-sample
t-test, simple linear regression). Older age, recent congestive heart failure, decreasing
fractional shortening, and recent onset of AF were independently associated with higher
PAP levels by multivariate analysis (linear regression). Among patients receiving
warfarin, PAP levels were not correlated with INR levels (linear regression, p = 0.60).
Patients classified as high-risk for thromboembolism by our risk stratification criteria
(systolic blood pressure >160 mm Hg, prior thromboembolism, recent congestive heart
failure, poor left ventricular function, and women over age 75) had higher PAP levels
than low-risk patients (antilog mean PAPln 5.6 vs 4.9, p <0.001, two-sample t-test). PAP levels in patients with AF are associated
with clinical characteristics predictive of thromboembolism. Elevated PAP levels are
particularly associated with poor left ventricular function and are not affected by
anticoagulation. PAP levels may be a marker of stroke risk in patients with AF.
Presented in part at the American Heart Association 22nd annual Joint Conference on
Stroke and the Cerebral Circulation, Anaheim, CA, February, 1997.
Keywords
Atrial fibrillation - plasmin - hemostatic markers