Left ventricular function after late thrombolysis with alteplase in myocardial infarction.
OBJECTIVE
Late thrombolytic treatment (after 6 hours from pain onset) for acute myocardial infarction has been shown to improve survival in a cohort of patients. The mechanisms underlying such benefit have been debated and a controversy exists about the influence of late thrombolysis over left ventricular function as one potential mechanism. The present study intended to clarify the effects of late thrombolysis with alteplase on left ventricular function parameters.


METHODS
Prospective, multicenter, randomised, double-blind study. Ancillary study to LATE trial.


METHODS
We studied 103 patients, 81.6% men, randomly allocated to alteplase (100 mg over 3 hours) or placebo 6 to 24 hours after onset of myocardial infarction.


METHODS
Left ventricular function parameters by radionuclide ventriculography were evaluated at 1 and 6 months after myocardial infarction.


RESULTS
At 1 month, left ventricular ejection fraction was 48.86% on alteplase and 43.19% in placebo group (p = 0.028), with greater benefits for septal and apical regions. At 6 months no significant differences were found.


CONCLUSIONS
Those data suggest that late thrombolysis with alteplase improves left ventricular function 1 month after myocardial infarction although the difference did not persist at 6 months. Improvement of left ventricular function shall, therefore, be considered as one of the possible mechanisms underlying the benefit of late thrombolysis.
Gil
V M
VM
Instituto do Coração, Carnaxide.
Ventosa
A
A
Antunes
A F
AF
Morais
J
J
Seabra-Gomes
R
R
D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology*; D010960:Plasminogen Activators / Q000627:therapeutic use*; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016277:Ventricular Function, Left / Q000187:drug effects*
D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator