 The majority of strokes and myocardial infarctions are due to atherothrombotic events. Impaired fibrinolytic activity increases the propensity for thromboembolic events. Many different candidate molecules have been studied as the cause of a hypercoagulable state. Plasminogen Activator Inhibitor-1 PAI-1 is the major physiologic inhibitor of the bodys fibrinolytic system including the principal serine protease tissue-type plasminogen activator t-PA. It is therefore poised to be a pivotal regulator of the fibrinolytic system.Recent studies have shown that PAI-1 levels are elevated in patients with obstructive sleep apnea OSA and that PAI-1 levels correlate with severity of OSA. 