Selective Matrix Metalloproteinase Inhibition Reduces Left Ventricular Remodeling but Does Not Inhibit Angiogenesis After Myocardial Infarction

Abstract

Background— Broad inhibition of matrix metalloproteinases (MMPs) attenuates left ventricular remodeling after myocardial infarction (MI). However, it is not clear if selective MMP inhibition strategies will be effective or if MMP inhibition will impair angiogenesis after MI. Methods and Results— We used a selective MMP inhibitor (MMPi) that does not inhibit MMP-1 in rabbits, which, like humans but unlike rodents, express MMP-1 as a major collagenase. On day 1 after MI, rabbits were randomized to receive either inhibitor (n=10) or vehicle (n=8). At 4 weeks after MI, there were no differences in infarct size or collagen fractional area. However, MMPi reduced ventricular dilation. The increase in end-diastolic dimension from day 1 to week 4 was 3.1±0.5 mm for vehicle versus 1.3±0.3 mm for MMPi (P<0.01). The increase in end-systolic dimension was 2.8±0.5 mm for vehicle and 1.3±0.4 mm for MMPi (P<0.05). Furthermore, MMPi reduced infarct wall thinning; the minimal infarct thickness was 0.8±0.1 mm for vehicle an...