Table 3.

Time Profile of CMR-Assessed Myocardium at Risk, Infarct Size, and Myocardial Salvage During the First Week After Reperfused Myocardial Infarction in Pigs

CMRFollow-Up
120 min After Reperfusion (n=20)24 h After Reperfusion (n=15)Day 4 After Reperfusion(n=10)Day 7 After Reperfusion(n=5)
MaR, % of left ventricle48.1 (6.0)3.6 (2.8)30.2 (6.2)30.1 (2.3)
Infarct size, % of left ventricle45.1 (5.3)35.3 (5.2)30.2 (4.3)25.4 (4.0)
Myocardial salvage, %4.7 (4.7)–1285 (858)–2.5 (20.3)15.7 (13.3)
  • Data are presented as mean (SD). CMR data for each time point correspond to pooled data from all animals undergoing 40 minutes ischemia/reperfusion. n values decrease over time because 5 pigs were euthanized after each CMR examination for histological measurement of water content.10 The extent of myocardium at risk was assessed by MDCT reference during coronary occlusion in all animals (MDCT-MaR). MDCT-MaR as assessed during the index coronary occlusion was 30.5±5.0%, 29.6±4.7%, 29.1±3.9%, and 28.3±4.3% of left ventricle; for pigs followed up to 120 minutes (n=20), 24 hours (n=15), 4 days (n=10), and 7 days (n=5) after reperfusion. Myocardial salvage as assessed by MDCT/CMR [(MDCT MaR – CMR Infarct Size)/MDCT MaR, %] in each of these groups was –50.6±24.4% at 120 minutes, –20.4±16.9% at 24 hours, –4.8±17.1% at 4 days, and 9.1±19.9% at 7 days after reperfusion, respectively. Note that MDCT was performed in all pigs only once (during the index ischemic event). Online-only Data Supplement Table III shows all individual data from animals euthanized at each time point.

  • CMR indicates cardiac magnetic resonance; MaR, myocardium at risk; and MDCT, multidetector computed tomography.