(A) Ejection fraction of sham-treated (n = 16) and intact (n = 16) and glutaraldehyde-inactivated (n = 16) extracellular matrix (ECM) scaffold–treated animals as measured by serial echocardiography. Significant effects were observed for time (p = 0.048) but not group (p = 0.38). Effect interaction (group × time) was significant (p = 0.0001) (repeated measures 2-way analysis of variance [ANOVA]). (B) Ejection fraction was also analyzed by pressure-volume loop analysis 14 weeks post-myocardial infarction (MI) (1-way ANOVA). Load-independent markers of cardiac performance including end-systolic pressure-volume relationship (ESPVR) (C), pre-load recruitable stroke work (PRSW) (D), and maximum pressure change divided by left ventricular end-diastolic volume (dP/dt max/LVEDV) (E) measured by pressure-volume (PV) loop at 14 weeks post-MI in sham-treated (n = 16) and intact (n = 16) and glutaraldehyde-inactivated (n = 16) ECM scaffold–treated animals (1-way ANOVA).