Objective: To describe the time course of myocardial infarct (MI) healing and left ventricular (LV) remodelling and to assess factors predicting LV remodelling using cardiac MRI.
Methods: In 58 successfully reperfused MI patients, MRI was performed at baseline, 4 months (4M), and 1 year (1Y) post MI RESULTS: Infarct size decreased between baseline and 4M (p < 0.001), but not at 1Y; i.e. 18 ± 11%, 12 ± 8%, 11 ± 6% of LV mass respectively; this was associated with LV mass reduction. Infarct and adjacent wall thinning was found at 4M, whereas significant remote wall thinning was measured at 1Y. LV end-diastolic and end-systolic volumes significantly increased at 1Y, p < 0.05 at 1Y vs. baseline and vs. 4M; this was associated with increased LV sphericity index. No regional or global LV functional improvement was found at follow-up. Baseline infarct size was the strongest predictor of adverse LV remodelling.
Conclusions: Infarct healing, with shrinkage of infarcted myocardium and wall thinning, occurs early post-MI as reflected by loss in LV mass and adjacent myocardial remodelling. Longer follow-up demonstrates ongoing remote myocardial and ventricular remodelling. Infarct size at baseline predicts long-term LV remodelling and represents an important parameter for tailoring future post-MI pharmacological therapies designed to prevent heart failure.