Intra-arterial thrombin activity produced by percutaneous transluminal angioplasty eliminated by segmentally enclosed thrombolysis

Thrombosis and intrinsic fibrinolysis in percutaneous transluminal angioplasty

Coagulation and fibrinolysis were investigated in 14 claudicants undergoing percutaneous transluminal angioplasty (PTA) for femoropopliteal artery lesions. Cross-linked fibrin degradation products (XL-FDP), tissue plasminogen activator (t-PA) antigen, fibrinopeptide A (FPA), and plasminogen activator inhibitor-1 (PAI-1) activity were measured in peripheral blood. XL-FDP and t-PA increased, and FPA and PAI-1 decreased significantly after angioplasty. XL-FDP increased from baseline 266 +/- 72 ng/ml to 481 +/- 239 ng/ml (p < 0.0005) 30 min after PTA, indicating mural thrombus formation in spite of the significant fall in FPA influenced by heparin. A groin haematoma developed after PTA in 4/6 patients, who received more than 5600 IU heparin and in 1/8 patients receiving smaller dosages. The alterations in PAI-1 showed no correlation with those of t-PA, whereas heparin had a sparing effect on PAI-1 consumption. These findings may indicate that PAI-1 acts as a thrombin inhibitor following deep vessel wall injury by angioplasty. In two patients, who had signs of rethrombosis on the next day, residual FPA was relatively high, XL-FDP peaked at 3530 +/- 1170 ng/ml, and t-PA increased by 2.6 +/- 1.0 ng/ml. The corresponding values in patients with an uncomplicated course were 406 +/- 89 ng/ml (p < 0.0001) and 0.1 +/- 0.5 ng/ml (p < 0.02). We conclude that thrombin promotes activation of coagulation and fibrinolysis in femoropopliteal PTA. Instability between these counteracting systems resulting in thrombosis is not prevented by conventional heparin administration at dosages causing bleeding complications.

Cross-linked fibrin degradation products (XL-FDP) as marker of early rethrombosis in percutaneous transluminal angioplasty

The thrombotic response to percutaneous transluminal angioplasty (PTA) was investigated in 31 patients treated for 1-10 cm femoropopliteal (n = 28) and tibial (n = 3) artery obstructions by measurement of cross-linked fibrin degradation products (XL-FDP) in peripheral blood samples drawn before and 30 min after PTA. XL-FDP increased from 400 +/- 147 ng/ml to 700 +/- 445 ng/ml (median +/- S.E., p = 0.0005). XL-FDP rose from 320 +/- 110 ng/ml to 540 +/- 102 ng/ml in 23 patients, whose ankle/brachial systolic blood pressure index (ABI) increased > 0.15 after PTA, whereas XL-FDP increased from 850 +/- 450 ng/ml to 2620 +/- 1472 ng/ml in eight patients, who failed to increase ABI in spite of preceding recanalisation. XL-FDP increased by more than 1000 ng/ml in 1/23 (4.3%) patients with uncomplicated PTA and in 6/8 (75%) patients with haemodynamic failure (p = 0.0005). Using a XL-FDP increase of 1000 ng/ml as cut-off, estimates of positive and negative predictive values (95% confidence limits) for early failure of PTA were 85.7% (42.1-99.6%) and 91.7% (73.0-99.0%), respectively. We conclude from this pilot study that femorotibial PTA produces a hypercoagulable state which may result in failure of early patency due to rethrombosis. We suggest for the first time XL-FDP as a marker of early rethrombosis in PTA, and report a sequential XL-FDP assay which may be useful for identification of high-risk patients requiring thrombolytic therapy after PTA for maintenance of early vascular patency.