Fibrinolytic response to acute exercise in patients with peripheral arterial disease

• Published in: Medicine and science in sports and exercise 2001-02, Vol.33 (2), p.214-219
• Main Authors: WOMACK, Christopher J, IVEY, Frederick M, GARDNER, Andrew W, MACKO, Richard F
• Format: Article
• Language: English
• Subjects: Aged; Arterial Occlusive Diseases - complications; Arterial Occlusive Diseases - pathology; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Exercise - physiology; Female; Fibrinolysis - physiology; Humans; Intermittent Claudication; Male; Medical sciences; Middle Aged; Plasminogen Inactivators - biosynthesis; Plasminogen Inactivators - pharmacology; Space life sciences; Tissue Plasminogen Activator - biosynthesis; Tissue Plasminogen Activator - pharmacology
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1097/00005768-200102000-00007

Elevations in tissue plasminogen activator (tPA) are postulated to protect against atherothrombotic events during exercise. However, fibrinolytic response to repetitive bouts of symptom-limited exercise is unknown in peripheral arterial disease (PAD) patients, a population with impaired fibrinolysis and increased risk for ischemic events. The purpose of the present study was to evaluate the fibrinolytic response to repetitive bouts of symptom-limited exercise in PAD patients. Nine (8 male, 1 female) patients with Fontaine State II PAD were studied. Fasting blood samples for determination of tPA and plasminogen activator inhibitor (PAI-1) were obtained into an acidified citrate solution via an indwelling venous catheter before, immediately after, 30 min after, and 60 min after submaximal treadmill walking. Patients walked intermittently at 65% of maximal intensity achieved on a previous graded exercise test until 30 min of exercise was achieved. Exercise increased tPA activity by 180% (0.5 +/- 0.16 IU.mL(-1) baseline, 1.4 +/- 1.2 IU.mL(-1) postexercise), and decreased PAI-1 activity by 40% (20.6 +/- 5.5 AU.mL(-1) baseline, 11.8 +/- 6.2 AU.mL(-1) postexercise), without changing tPA or PAI-1 antigen. Notably, plasma tPA activity levels 1 h after exercise remained elevated by 80%, whereas PAI-1 activity remained decreased by 49%. The decrease in PAI-1 significantly (P < 0.05) correlated with oxygen uptake (VO(2)) during submaximal exercise (r = -0.77). These findings demonstrate that repetitive bouts of symptom-limited exercise produce a substantial improvement in the fibrinolytic profile of PAD patients, which persists at least 1 h after exercise cessation.