, Pi - Chi Sun and Chun - Che Shih Ventricular Aneurysm Repair Extracellular Matrix Remodeling Attenuated After Experimental Postinfarct

Background. Left ventricular aneurysm repair (LVAR) prevents congestive heart failure after myocardial infarc-tion (MI). LV dilation after MI is related to postinfarct myocardial remodeling and leads to CHF. Because changes in matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and the physical properties of collagens are involved in myocardial remodeling, the effect of postinfarct LVAR on these factors was tested. Methods. Rats with surgically induced MI, which did or did not receive postinfarct LVAR, were compared with each other and with controls. TIMP messenger RNA and protein expression, MMP gelatin zymography activity, and collagen fibrosis were measured in heart tissue. Results. A threefold difference in the infarction area ratio was observed between samples of LVAs and of repaired LVAs. Compared with rats without LVAR, rats with repaired LVAs exhibited a higher percentage frac