Predictors of early and late ventricular remodeling after acute myocardialinfarction

Background: The determinants of the early and late stages of the ventricula r remodeling process after infarction are not well defined. Hypothesis: The study was undertaken to evaluate the factors that condition the time course of left ventricular dilation during the first 6 months aft er infarction. Methods: The study group consisted of 74 patients with a first intermediate -large (greater than or equal to 4 Q waves) acute myocardial infarction. Co ntrast left ventricular and coronary angiograms were performed at 7 +/- 1 a nd 175 +/- 25 days after infarction. Left ventricular volumes, regional fun ction and infarction artery status were quantified. Percutaneous translumin al coronary angioplasty (PTCA) was performed in the early angiogram in 31 p atients. Results: In the early angiogram, 13 patients showed ventricular remodeling (end-diastolic volume > 90 ml/m(2)). A larger extent of dysfunction was the only predictor (p < 0.002) of early remodeling. At 6 months, a smaller, ea rly end-diastolic volume (p < 0.0001) and a poorer regional function recove ry (p < 0.05) were independently related to late diastolic enlargement, and a poorer regional function recovery (p < 0.0001) and a smaller, early end- systolic volume (p < 0.009) were independently related to late systolic enl argement. One patient with compared with 20 patients without early remodeli ng (p < 0.04) presented with late remodeling (increment of the end-diastoli c volume > 20% at 6 months). In patients with early remodeling, the end-dia stolic volume did not change significantly (101 +/- 13 vs. 94 +/- 22 ml/m(2 ), NS) at 6 months; despite this, they maintained larger diastolic volumes than patients with late remodeling (81 +/- 12 ml/m(2), p < 0.04) at 6 month s. Infarction artery status did not influence the evolution of ventricular volumes and regional function. Conclusions: (1) A large infarct size is the main determinant of postinfarc tion remodeling. (2) Such infarct size-dependent ventricular dilation occur s early and does not tend to increase in late stage; in contrast, some case s of intermediate-large size infarcts without early remodeling exhibit late remodeling associated with a poor late recovery of regional function. (3) Recovery of regional function (indicating myocardial viability) rather than infarction artery status plays a role in the late ventricular remodeling p rocess.