EFFECT OF INFARCT ARTERY PATENCY ON PROGNOSIS AFTER ACUTE MYOCARDIAL-INFARCTION

Citation
Ga. Lamas et al., EFFECT OF INFARCT ARTERY PATENCY ON PROGNOSIS AFTER ACUTE MYOCARDIAL-INFARCTION, Circulation, 92(5), 1995, pp. 1101-1109
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Hematology
Journal title
ISSN journal
0009-7322
Volume
92
Issue
5
Year of publication
1995
Pages
1101 - 1109
Database
ISI
SICI code
0009-7322(1995)92:5<1101:EOIAPO>2.0.ZU;2-G
Abstract
Background In patients with acute myocardial infarction (MI), early re storation of patency of the infarct-related artery (IRA) leads to pres ervation of left ventricular function and improved clinical outcome. H owever, there is evidence that the benefits associated with a patent I RA are out of proportion to the observed improvement in ventricular fu nction and may result not only from salvage of ischemic myocardium but also from the opening of the IRA beyond a narrow postinfarct time win dow. The objectives of this study were (1) to assess the effect of IRA patency on outcome of patients after acute MI with left ventricular d ysfunction while controlling for differences in left ventricular eject ion fraction and the extent of coronary disease and (2) to determine t he effect of angiotensin-converting enzyme (ACE) inhibitor therapy on patients with patent as well as occluded infarct arteries. Methods and Results The Survival and Ventricular Enlargement (SAVE) study consist ed of 2231 patients with a documented MI and a left ventricular ejecti on fraction less than or equal to 40%. They were randomized to the ACE inhibitor captopril (50 mg TID) or placebo 3 to 16 days after MI and were followed for an average of 3.5 years. Left ventricular ejection f raction, measured with radionuclide left ventriculography, was repeate d at the end of the follow-up period. The 946 patients in whom the pat ency of the IRA was established before randomization form the basis of this study. At cardiac catheterization averaging 4.2 days after infar ction, 30.7% of patients had an initially oc-cluded IRA. After revascu larization, 162 of the 946 patients (17.1%) were left with an occluded IRA at the time of randomization. The 162 patients with persistently occluded IRAs and 784 with patent IRAs had similar clinical baseline c haracteristics, but those with occluded arteries had a slightly lower ejection fraction than the 784 patients with patent infarct arteries ( 30% versus 32%, P=.01). Cox proportional-hazards analyses showed that the independent predictors of all-cause mortality were hypertension (r elative risk [RR] 1.94, P<.001), number of diseased coronary arteries (RR 1.68, P<.001), occluded IRA (RR 1.49, P=.039), ejection fraction ( RR 1.36, P<.001), age (RR 1.10, P=.030), and use of beta-adrenergic re ceptor blocking agents (RR 0.60, P=.007). Independent predictors of a composite end point consisting of cardiovascular mortality, morbidity, or reduction of ejection fraction of greater than or equal to 9 units were occluded IRA (odds ratio [OR] 1.73, P=.002), hypertension (OR 1. 71, P<.001), number of diseased Vessels (OR 1.38, P<.001), ejection fr action (OR 1.18, P=.003), use of beta-adrenergic receptor blocking age nts (OR 0.67, P=.007), and randomization to captopril (OR 0.70, P=.009 ). Conclusions IRA patency within 16 days after MI predicts a favorabl e clinical outcome, independent of the number of obstructed coronary a rteries or of left ventricular function. The beneficial effect of ACE inhibition is independent of patency status of the IRA. These findings support the need for additional, prospective clinical trials of late reperfusion in MI patients.