changes in LV chamber size, shape, muscle mass, and function. 1-3 Progressive LV dilation after AMI is associ- Left ventricular (LV) remodeling after acute myocar- dial infarction (AMI) is a dynamic process of progressive From the a Fondazione Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico, Veruno, the b Ospedale Bassini, Cinisello Balsamo, the c Centro Studi Associazione Nazionale Medici Cardiologi Ospedalieri, Firenze, the d Ospedale S. Matteo, Pavia, the e Ospedale Civile, Udine, the f Ospedale Civile, Pordenone, the g Ospedale Civile, S. Vito al Tagliamento, the h Ospedale Civile, Rho, the i Ospedale Civile, Vasto, and the j Ospedale Cervello, Palermo, Italy. Endorsed by the Associazione Nazionale Medici Cardiologi Ospedalieri and the Istituto di Ricerche Farmacologiche “Mario Negri,” Milan, Italy, and supported in part by grants from Zeneca, Italy, Schwarz-Pharma, Italy, and the Cardiovascular Research Foundation, Bad Schwalbach, Germany. Imaging and Diagnostic Testing Heterogeneity of left ventricular remodeling after acute myocardial infarction: Results of the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico-3 Echo Substudy Pantaleo Giannuzzi, MD, a Pier Luigi Temporelli, MD, a Enzo Bosimini, MD, a Francesco Gentile, MD, b Donata Lucci, BS, c Aldo Pietro Maggioni, MD, c Luigi Tavazzi, MD, d Luigi Badano, MD, e Ioanna Stoian, MD f , Rita Piazza, MD, g Ioanna Heyman, MD, h Giacomo Levantesi, MD, i Eugenio Cervesato, PhD, f Enrico Geraci MD, j and Gian Luigi Nicolosi, MD, f for the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico-3 Echo Substudy Investigators Veruno, Cinisello Balsamo, Firenze, Pavia, Udine, Pordenone, S. Vito al Tagliamento, Rho, Vasto, and Palermo, Italy Background Left ventricular (LV) remodeling after acute myocardial infarction has still to be clarified in the throm- bolytic era. Methods To evaluate timing and the magnitude and pattern of postinfarct LV remodeling, a subset of 614 patients enrolled in the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico-3 Echo Substudy underwent serial 2-dimensional echocardiograms at 24 to 48 hours from symptom onset (S1), at hospital discharge (S2), at 6 weeks (S3), and at 6 months (S4) after acute myocardial infarction. Results During the study period the end-diastolic volume index (EDVi) increased (P < .001) and wall motion abnormali- ties (%WMA) decreased (P < .001), whereas ejection fraction (EF) remained unchanged. Nineteen percent of patients showed a > 20% increase in EDVi at S2 compared with S1 (severe early dilation), and 16% of patients showed a > 20% dilation at S4 compared with S2 (severe late dilation). Independent predictors of severe in-hospital LV dilation were rela- tively small EDVi (odds ratio [OR] 0.961, 95% confidence interval [CI] 0.947-0.974, P = .0001) and relatively large %WMA (OR 1.030, 95% CI 1.013-1.048, P = .0005). Similarly, smaller predischarge EDVi (OR 0.975, 95% CI 0.963- 0.987, P = .0001), greater %WMA (OR 1.026, 95% CI 1.008-1.045, P = .0042), and moderate to severe mitral regurgi- tation (OR 2.261, 95% CI 1.031-4.958, P = 0.0417) independently predicted severe late dilation. Importantly, 92% of the patients with severe early dilation did not have further dilation at S4, and 91% of patients with severe late dilation did not have in-hospital dilation. EF was unchanged over time in patients with early dilation, whereas it significantly decreased in those with late dilation. Conclusions Although in-hospital LV enlargement is not predictive of subsequent dilation and dysfunction, late remod- eling is associated with progressive deterioration of global ventricular function over time: patients with extensive %WMA and not significantly enlarged ventricular volume before discharge are at higher risk for progressive dilation and dysfunc- tion. (Am Heart J 2001;141:131-8.) Investigators and institutions participating in the GISSI-3 Echo Substudy are listed in the Appendix. Submitted May 15, 2000; accepted August 31, 2000. Reprint requests: Pantaleo Giannuzzi, MD, Fondazione “Salvatore Maugeri,” IRCCS, Via Revislate, 13, 28010 Veruno (NO), Italy. E-mail: pgiannuzzi@fsm.it Copyright © 2001 by Mosby, Inc. 0002-8703/2001/$35.00 + 0 4/1/111260 doi:10.1067/mhj.2001.111260