COL1A1 and myocardial infarction: Circulating plasma levels of extracellular matrix turnover (MMP-9 and TIMP-1), measured at 1 and 5 weeks post-AMI, did not differ significantly between treatment groups (Fig. 3), although there was a trend towards an increase in TIMP-1 expression in the infarcted area in IPTVVI vs. MI control (Table 2, P = 0.09, two-tailed), that together with the increased Col1a1 expression may reflect increased ECM turnover.