Table 2.

Time Profile of MaR, IS and Myocardial Salvage as Assessed by CMR During the First Week After Reperfused Myocardial Infarction in Pigs Subjected to Different I/R Protocols and Cardioprotective Strategies

GroupCMR MeasureFollow-Up
R-120 minR-24 hR-Day 4R-Day 7
40-min I/R (controls)MaR, % of LV42.9 (5.7)2.2 (1.7)27.1 (3.4)30.1 (2.3)
IS, % of LV39.2 (3.8)30.2 (3.1)28.2 (4.6)25.4 (4.0)
Myocardial salvage, %8.3 (6.4)−1310 (996)−4.4 (14.2)15.7 (13.3)
40-min I/R+PostCMaR, % of LV48.8 (6.2)*1.9 (2.0)33.9 (4.9)*32.5 (3.2)
IS, % of LV46.2 (5.6)*33.1 (3.4)32.8 (4.5)*30.4 (3.6)*
Myocardial salvage, %5.2 (4.8)−1060 (513)3.3 (3.9)6.6 (3.0)
PreC+40-min I/RMaR, % of LV29.1 (1.4)*4.2 (1.4)24.6 (7.5)17.2 (5.7)*
IS, % of LV21.0 (7.2)*18.5 (10.2)*7.5 (3.7)*6.1 (4.7)*
Myocardial salvage, %28.2 (22.6)*−389 (361)*68.0 (13.6)*64.0 (23.9)*
20-min I/RMaR, % of LV27.7 (3.3)*3.6 (1.1)4.2 (2.2)*2.2 (1.9)*
IS, % of LV6.1 (4.5)*3.0 (1.0)*2.2 (0.8)*1.5 (0.8)*
Myocardial salvage, %78.8 (13.7)*17.3 (18.7)*25.2 (75.5)3.4 (79.0)
  • Values are mean (SD). A bimodal trend over time after reperfusion was observed for CMR-MaR and CMR-salvage ([CMR MaR−CMR IS]/CMR MaR, %) in all groups of pigs with the exception of the 20-min I/R group in which a negative linear trend or no clear trend was shown for CMR-MaR and salvage, respectively. In contrast, a strong negative linear trend over time was shown for IS in all groups. P values for significant trends were all <0.01. CMR indicates cardiac magnetic resonance; I/R, ischemia/reperfusion; IS, infarct size; LV, left ventricle; MaR, myocardium at risk; PostC, postconditioning; PreC, preconditioning; and R, reperfusion.

  • * Statistically significant differences (P<0.05) as compared with the same time point in the 40- min I/R (control) group. P value is adjusted for multiple comparisons among groups for each time point and imaging parameter.