Related Experiment Videos
Fibrinolytic activity is similar in physically active men with and without a history of myocardial infarction
B Fernhall1, L M Szymanski, P A Gorman
1Exercise Science Programs, George Washington University Medical Center, Washington, DC 20052, USA. boexsci@gwis2.circ.gwu.edu
Insights
Physically active men with and without coronary artery disease (CAD) showed similar functional fibrinolytic activity, challenging previous findings. Careful matching of participants by age and activity levels is crucial for accurate fibrinolytic potential assessment.
Area of Science:
- Cardiovascular Physiology
- Hemostasis and Thrombosis
Background:
- Coronary artery disease (CAD) impacts cardiovascular health.
- Fibrinolytic potential plays a role in clot lysis and cardiovascular events.
- Previous studies suggest altered fibrinolysis in CAD patients.
Purpose of the Study:
- To compare fibrinolytic potential at rest and after exercise in men with and without a history of myocardial infarction (MI).
- To investigate the relationship between fibrinolytic markers and cardiorespiratory fitness (VO2max).
Main Methods:
- Study included men with MI history and age/activity-matched controls without CAD, all in exercise programs.
- Measured tissue-type plasminogen activator (TPA) and plasminogen activator inhibitor 1 (PAI-1) activity and antigen levels.
- Assessed fibrinolytic potential at rest and post-maximal exercise, using ANOVA and regression analyses.
Main Results:
- No significant differences in resting or post-exercise TPA and PAI-1 activity between groups.
- Higher resting TPA antigen levels observed in the CAD group.
- VO2max positively correlated with post-exercise TPA activity and negatively with resting TPA antigen.
Conclusions:
- Functional fibrinolytic activity appears similar in physically active men with and without CAD.
- Age and habitual physical activity matching are critical for evaluating fibrinolytic potential.
- Exercise intensity control is important in studies assessing fibrinolysis in cardiovascular populations.
Abstract:
The purpose of this study was to evaluate fibrinolytic potential at rest and after a fibrinolytic stressor in men with a history of myocardial infarction (MI) compared with an age- and activity-matched group of men without coronary artery disease (CAD). All men were currently enrolled in exercise programs. Tissue-type plasminogen activator (TPA) and plasminogen activator inhibitor 1 (PAI-1) activity and antigen levels were measured at rest and after a maximal exercise test. A 2 x 2 (group x time) ANOVA with repeated measures was used to evaluate fibrinolytic potential. Bivariate regressions were conducted to evaluate relations between fibrinolytic potential and maximal oxygen uptake (VO2max). Age was similar between groups (CAD, 57.5 +/- 6.6; non-CAD, 58.1 +/- 7.3 years); however, VO2max was higher in non-CAD subjects (36.2 +/- 6.2 vs 27.5 +/- 5.9 mL.kg-1.min-1). Mean +/- SEM resting TPA and PAI-1 activities were similar between CAD and non-CAD subjects (TPA, 2.8 +/- 0.2 vs 2.8 +/- 0.2 IU/mL; PAI-1, 15.9 +/- 3.1 vs 13.1 +/- 4.1 AU/mL). Both groups showed similar significant increases in TPA activity with exercise (P < .05), and postexercise TPA activity was also similar (CAD, 9.1 +/- 2.0 IU/mL; non-CAD, 11.7 +/- 2.6 IU/mL). Both groups also showed similar significant decreases in PAI-1 activity with exercise (P < .05) and no differences in postexercise PAI-1 activity (CAD, 13.2 +/- 2.5 AU/mL; non-CAD, 10.4 +/- 3.6 AU/mL). Significantly higher resting TPA antigen levels were seen in CAD (14.8 ng/mL) than non-CAD (10.2 ng/mL) subjects (P < .05), but neither group showed significant changes with exercise (CAD, 12.9 ng/mL; non-CAD, 11.8 ng/mL). Resting PAI-1 antigen was similar in the two groups (CAD, 71.4 ng/mL; non-CAD, 74.2 ng/mL) and did not significantly change with exercise (CAD, 77.9 ng/mL; non-CAD, 72.3 ng/mL). VO2max was positively correlated with postexercise TPA activity (r = .52, P < .05) and negatively correlated with resting TPA antigen (r = -.43, P < .05). Resting TPA antigen was also directly correlated with body mass index (r = .63, P < .05). The finding that functional fibrinolytic activity was not different in physically active men with and without CAD contrasts with previous reports. This suggests that matching subjects on the bases of age and habitual physical activity status and controlling exercise intensity are important factors to consider when evaluating fibrinolytic potential.