title: Plasma tissue plasminogen activator and plasminogen activator inhibitor-1 levels in acute myocardial infarction.
abstract: The cause of the circadian variation in the incidence of acute myocardial infarction (AMI) has not been identified. Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) have opposing effects on thrombi. Hence, the extent of the clot, the size of the infarct and outcome of patients could depend on t-PA and PAI-1 levels. In an effort to elucidate the pathophysiologic basis of circadian variation of AMI, we investigated the presence of a possible corresponding circadian variation in the levels of endogenous t-PA and PAI-1 in patients diagnosed to have AMI and the effects of hypertension, diabetes and site of the infarct on these levels. We estimated the levels of t-PA and PAI-1 in platelet-poor plasma of 42 patients with AMI on admission, using the enzyme-linked immunosorbant assay. Although not statistically significant, patients having an AMI in the morning hours had the highest t-PA:PAI-1 ratio. The normal circadian variation in PAI-1 levels was lost in patients with AMI, probably due to the disease process. Also, the t-PA levels in hypertensive patients were significantly lower than in nonhypertensives. PAI-1 levels were also significantly lower in patients with anteroseptal than in inferior and anterolateral AMI. This relationship between the fibrinolytic potential and the site of infarction needs further study. Furthermore, t-PA levels on admission were significantly lower in survivors and may have a predictive value in determining the outcome.
authors.affiliation: Department of Internal Medicine, University of North Dakota, School of Medicine and Health Sciences, Fargo, N. Dak 58102, USA. aganti@medicine.nodak.edu
authors.forename: Apar Kishor
authors.initials: AK
authors.lastname: Ganti
authors.forename: Anil
authors.initials: A
authors.lastname: Potti
authors.forename: Radha
authors.initials: R
authors.lastname: Yegnanarayan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm / Q000502:physiology; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000209:etiology / Q000401:mortality; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood*; D015996:Survival Rate; D010959:Tissue Plasminogen Activator / Q000097:blood*
chemical_list: D017395:Plasminogen Activator Inhibitor 1; D010959:Tissue Plasminogen Activator