ROLE OF INFARCTION ARTERY STATUS IN LEFT-VENTRICULAR REMODELING AFTERACUTE MYOCARDIAL-INFARCTION

The aim of this study was to evaluate the relation between the infarct ion artery status and left ventricular volumes, independently of regio nal ventricular dysfunction, at 4-6 weeks after a first myocardial inf arct ion. The study group consisted of 100 patients, of whom 80 receiv ed thrombolytic treatment. Coronary and contrast left ventricular angi ograms were performed at 36+/-5 days postinfarction. Left ventricular end-diastolic and end-systolic volumes were measured. The centerline c hord motion method was used to calculate the extent of wall motion abn ormality (percentage of chords with hypokinetic motion) and its severi ty (maximum units of S.D. below the normal wall motion reference). Min imum lumen diameter, patency and collateral flow in the infarction art ery were also analyzed. Eight patients (group I) showed occlusion with poor collateral flow in the infarction artery, 22 patients (group II) occlusion with good collateral flow, 38 patients (group III) severe r esidual stenosis (minimum lumen diameter less than or equal to 1 mm), and 32 patients (group IV) non-severe residual stenosis (minimum lumen diameter >1 mm). Patients from group I presented greater wall motion abnormality in terms of both extent (P=0.005) and severity (P=0.007), and greater end-diastolic (P=0.07) and end-systolic (P=0.0008) volumes ; there were no differences among groups II, III and IV. By stepwise m ultivariate regression analysis, the extent of wall motion abnormality was the main determinant of end-diastolic (P=0.0001) and end-systolic (P=0.0001) volumes; occlusion with poor collateral how was also a sig nificant independent factor for end-systolic volume (P=0.03). Total oc clusion (including both with and without collaterals) and the minimum lumen diameter did not correlate with end-diastolic and end-systolic v olumes. We concluded that (A) the extent of regional dysfunction is th e primary determinant of left ventricular volumes at 4-6 weeks postinf arction. (B) The status of the infarction artery is a weak predictor o f end-diastolic volume, which is the best descriptor of ventricular re modeling, although occlusion with poor collateral flow is associated t o larger end-systolic volume. (C) 1997 Elsevier Science Ireland Ltd.