Summary
Indices of fibrinogen cleavage by thrombin (fibrinopeptide A, FPA); by plasmin (BB1-42
and serum FDP); of the platelet release reaction (betathromboglobulin and platelet
factor 4); and antithrombin III (AT III) levels were measured serially in 46 patients
with pulmonary emboli in whom either substantial (SR) or impaired (IR) resolution
was documented. The mean FPA level in the 25 patients with IR was significantly higher
than the level in the 21 patients with SR (p <0.01). The increased thrombin activity
in the IR group was not due to AT III deficiency or increased platelet reactivity
but the elevated FPA levels in the presence of therapeutic levels of anticoagulation
indicated that the dose of heparin was inadequate. The higher BB1-42 and FDP levels
in this group reflected the increased plasmin activity that follows increased thrombin
activity. In a multivariate discriminant analysis, only the FPA data could be used
to predict the degree of resolution.
Increased thrombin action impairs resolution presumably by producing greater amounts
of accreted fibrin on the impacted embolus.
Keywords
Fibrinogen proteolysis in pulmonary embolism
