Fibrinogen and markers of fibrinolysis and endothelial damage following resolution of critical limb ischaemia

Objectives:To assess the effects of resolution of critical limb ischaemia on the elevated plasma fibrinogen, cross-linked fibrin degradation products (FDP), and von Willebrand factor antigen (vWF) levels, reported in peripheral arterial occlusive disease.Design:A prospective study of patients undergoing surgery for chronic critical limb ischaemia.Setting:Two vascular surgery units providing tertiary referral services for the West of Scotland.Materials:Venous blood samples were assayed for plasma fibrinogen, FDP D-dimer, and vWF levels, prior to surgery, together with fibrinolytic and rheological parameters, in 82 patients. Sampling was repeated 4 months after resolution of critical limb ischaemia.Outcome measures:Levels of these parameters following successful resolution of critical limb ischaemia were compared with pre-operative levels, and with an age-matched random population sample.Main results:Plasma fibrinogen and vWF levels were significantly lower (both p < 0.005, Wilcoxon matched pairs) following successful resolution of critical limb ischaemia in the 56 patients available for review, although levels remained higher than in population controls (p < 0.01, Mann-Whitney U-test). FDP levels were unchanged following surgery, remaining higher than in age-matched population controls (p < 0.01).Conclusions:Resolution of critical limb ischaemia fails to reduce plasma fibrinogen, fibrin turnover, and vWF levels to those seen in population controls. This implies that increased fibrinogen and fibrin turnover in peripheral arterial disease is not solely a consequence of tissue ischaemia, while the persisting prothrombotic state following resolution of critical limb ischaemia has potentially important implications for graft and patient survival

Acute exercise and markers of endothelial injury in peripheral arterial disease

Objectives:To determine the acute effects of exercise on plasma levels of markers of endothelial damage in patients with symptomatic peripheral arterial occlusive disease (PAOD).Design:Prospective observational study of patients with angiographically proven PAOD undergoing treadmill exercise testing prior to surgical or radiological intervention.Materials and methods:Ante-cubital venous blood sampling was performed in 20 patients with symptomatic PAOD prior to, and 2 min after, treadmill exercise testing. Samples were then assayed for von Willebrand factor (vWf), tissue-type plasminogen activator (tPa), and plasminogen activator inhibitor (PAI) levels.Results:Despite a significant fall in median ankle-brachial pressure indices from 0.96 pre-exercise to 0.59 post-exercise on the right, and from 0.92 to 0.40 on the left (both p<0.005), there were no significant changes in plasma levels of vWf, tPa, or PAI following claudication-inducing exercise.Conclusions:Claudication-inducing exercise does not produce acute alterations in plasma markers of endothelial damage, and the results of this study do not support the belief that claudication-inducing exercise in PAOD is damaging to vascular endothelium