Heterogeneous fate of perfusion and contraction after anterior wall acute myocardial infarction and effects on left ventricular remodeling

After acute myocardial infarction, potency of infarct vessel and extent of left venticular (LV) dysfunction are major determinants of ventricular remo deling. Spontaneous, delayed reperfusion in the infarct zone occurs in a si zeable number of patients well after the subacute phase. The aim of this st udy was to determine the relation between the occurrence of this spontaneou s, delayed reperfusion and LV remodeling. In 84 patients, resting LV volume s, topography, regional function, and perfusion were quantitatively evaluat ed by 2-dimensional echocardiography and sestamibi tomography 5 weeks (stud y 1) and 7 months (study 2) after anterior Q-wave infarction. At study 2, L V end-diastolic volume increased by >15% in 17 patients (20%, LV remodeling ); they had already had at study 1 significantly larger LV volumes, more se vere hypoperfusion and wall motion abnormalities, and greater regional dila tion than patients with stable LV volumes. Delayed reperfusion occurred in 8 of 17 patients with and in 42 of 67 patients without LV remodeling (47% v s 63%; p = NS). At study 2, LV regional dilation and end-diastolic volumes were stable in patients with, but increased in patients without, spontaneou s reperfusion (from 25 +/- 24% to 29 +/- 26% at study 2 [p<0.05] and from 6 5 +/- 14 to 68 +/- 18 ml/m(2) [p<0.05]). At multivariate analysis, however, regional ventricular dilation at study 1 was the sole predictor of further LV remodeling. Thus, after acute myocardial infarction, spontaneous reperf usion occurring after 5 weeks plays only a minor role in influencing LV rem odeling. Benefits from delayed reperfusion seem limited to patients with pr eserved LV volumes; patients with an enlarged left ventricle 5 weeks after acute infarction are prone to further LV remodeling, irrespective of delaye d reperfusion. (C) 1998 by Excerpta Medico, Inc.