Microvascular obstruction after successful fibrinolytic therapy in acute myocardial infarction. Comparison of reteplase vs reteplase+abciximab: A cardiovascular magnetic resonance study
Abstract:
Overview
Background. About one third of patients with TIMI 3 after reperfusion have evidence
of microvascular obstruction (MO) which represents an independent predictor of myocardial
wall rupture. This explains all efforts made to prevent MO. Magnetic resonance imaging
(MRI) has proved to be particularly useful in detecting MO. The aim of this study was to evaluate
with MRI if different fibrinolytic regimens in acute myocardial infarction display different effects
on left ventricle (LV) volumes and ejection fraction (EF), as well as on myocardial infarct size
(MIsz) and MO.
Methods. Twenty male patients, mean age 58 years, affected by acute myocardial infarction, ten
anterior and ten inferior, were treated with: full dose reteplase in ten, and half dose reteplase plus
full dose abciximab (R+Abcx) in the other ten patients. In the fourth day after hospital admission,
MRI STIR T2 images were used to quantify MIsz, while 2dflash cineloops were used after the injection
of gadolinium, to quantify LV volumes, EF and to detect MO.
Results. LV EF was higher in R+Abcx 51±10 than in reteplase 41±8. MIsz was similar in both
treatment groups: however a close relationship was present between MIsz and EF in the
reteplase group indicating that the greater the MIsz the lower the EF. In R+Abcx this relationship
was no longer present, suggesting a protective effect of the drug on microcirculation. In fact extensive
MO was present in 25% of all cases, 80% of which in the reteplase group while only 20%
in R+Abcx.
Conclusion. R+Abcx prevents MO: compared to traditional fibrinolytic therapy it allows better
LV function and most likely improved long term survival. (Heart International 2006; 2: 54-65)
Keywords
Magnetic resonance, Myocardial infarction, Microvascular obstruction
Article:
Article Information:
Correspondence
Antonello Zoni, MD, Heart Department, University Hospital of Parma, Via Gramsci, 14, 43100 Parma – Italy, antonello.zoni@libero.it
