Association between heart rate recovery after exercise testing and plasminogen activator inhibitor 1, tissue plasminogen activator, and fibrinogen in apparently healthy men.
OBJECTIVE
Delayed heart rate recovery (HRR) following exercise testing, an indicator of decreased autonomic nervous system activity, is associated with an increased risk of cardiovascular events. Because autonomic nervous system function may be associated with fibrinolytic factors, we tested the hypothesis that delayed HRR is associated with elevated fibrinolytic factors.


METHODS
In 547 (mean age 49.4+/-6.9 years) healthy men who underwent exercise treadmill testing and fasting blood analysis for fibrinolytic factors, we calculated HRR as the difference between maximum heart rate during the test and heart rate 1 min after cessation of exercise.


RESULTS
HRR was inversely correlated with plasminogen activator inhibitor 1 (PAI-1) activity (r=-0.23, p<0.001), tissue plasminogen activator (t-PA) antigen (r=-0.19, p<0.001), and fibrinogen (r=-0.11, p<0.05). Men in the lowest quartile of HRR had significantly higher PAI-1, t-PA, and fibrinogen than men in the highest quartile of HRR (all p trend <0.001). HRR was independently associated with PAI-1 (beta=-0.12, p<0.01) and fibrinogen (beta=-0.09, p=0.04) but not t-PA (beta=-0.06, p=0.29) in a multiple regression analysis.


CONCLUSIONS
These results suggest that delayed HRR after exercise testing is associated with elevated fibrinolytic factors in cross-section. The presence of other CHD risk factors does not explain this association, but further research is needed to identify the direction of the association.
Jae
Sae Young
SY
Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign, 1207 S. Oak, St, Champaign, IL 61820, USA. jae@uiuc.edu
Carnethon
Mercedes R
MR
Ahn
Eui Soo
ES
Heffernan
Kevin S
KS
Choi
Yoon-Ho
YH
Lee
Moon-Kyu
MK
Fernhall
Bo
B
D000328:Adult; D003327:Coronary Disease / Q000453:epidemiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005340:Fibrinogen / Q000378:metabolism*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000502:physiology; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D012044:Regression Analysis; D012307:Risk Factors; D010959:Tissue Plasminogen Activator / Q000097:blood*
D017395:Plasminogen Activator Inhibitor 1; C051321:SERPINE1 protein, human; D005340:Fibrinogen; D010959:Tissue Plasminogen Activator