LATE REPERFUSION FOR ACUTE MYOCARDIAL-INFARCTION LIMITS THE DILATATION OF LEFT-VENTRICLE WITHOUT THE REDUCTION OF INFARCT SIZE

Citation
A. Hirayama et al., LATE REPERFUSION FOR ACUTE MYOCARDIAL-INFARCTION LIMITS THE DILATATION OF LEFT-VENTRICLE WITHOUT THE REDUCTION OF INFARCT SIZE, Circulation, 88(6), 1993, pp. 2565-2574
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Hematology
Journal title
Circulation → ACNP
ISSN journal
0009-7322
Volume
88
Issue
6
Year of publication
1993
Pages
2565 - 2574
Database
ISI
SICI code
0009-7322(1993)88:6<2565:LRFAML>2.0.ZU;2-5
Abstract
Background. While previous clinical studies have shown a possible bene ficial effect of the reperfusion performed at a relatively late phase of acute myocardial infarction (''late reperfusion'') in preventing le ft ventricular enlargement, the mechanism has not been clarified. Meth ods and Results. Of 89 patients with an initial anterior myocardial in farction, reperfusion was successful in 69. These 69 were divided into three groups according to the time required to achieve reperfusion af ter the onset of symptoms: early-reperfused (<3 hours from the onset t o reperfusion; n=22), intermediate-reperfused (3 to 6 hours from the o nset to reperfusion; n=2), and late-reperfused (>6 hours from the onse t to reperfusion; n=19). The 20 patients whose infarct-related artery were occluded in the acute phase as well as 1 month later was classifi ed as nonreperfused. Infarct size, evaluated as defect volume by Tl-20 1 single-photon emission computed tomography 1 month after the onset, was 1593+/-652 units (mean+/-SD) in the late-reperfused group, signifi cantly larger (P<.05) than that of the intermediate-reperfused (1066+/ -546 U) or the early-reperfused groups (372+/-453 U) but not different from that of the nonreperfused group (1736+/-562 U). Wall motion abno rmality index as well as global ejection fraction evaluated by left ve ntriculography 1 month after the onset showed that late reperfusion di d not preserve the left ventricular wall motion and function. These re sults indicate that the earlier reperfusion decreased the size of the infarction and preserved left ventricular function, whereas late reper fusion (>6 hours after onset) did not limit infarct size or preserve l eft ventricular function. In contrast, the end diastolic volume index did not differ significantly among the early-reperfused (50+/-15 mL/m( 2)), intermediate-reperfused (54+/-14 mL/m(2)), and late-reperfused (5 3+/-19 mL/m(2)) groups; those were significantly smaller than that of the nonreperfused group (68+/-12 mL/m(2); P<.05). Left ventriculograph ic data obtained in both the acute and chronic phase in 39 patients sh owed that left ventricular volumes increased significantly during the course of myocardial infarction only in the nonreperfused group. Concl usions. Late reperfusion appeared to prevent ventricular dilatation fo llowing acute myocardial infarction independent of the limitation of i nfarct size.