IABP counterpulsation accelerated early LV ejection fraction improvement at 6 hours (36% vs 26%, P=0.015) but did not significantly improve recovery at 24 hours (38% vs 35%, P=0.34) after AMI.
RCT (n=14)
Does IABP counterpulsation improve the recovery of LV systolic function after reperfused acute myocardial infarction in an experimental model?
In an experimental dog model, IABP counterpulsation accelerates but does not significantly improve the overall recovery of LV systolic function 24 hours after reperfused AMI.
Absolute Event Rate: 38% vs 35%
p-value: p=0.34
AIMS: We sought to determine whether intra-aortic balloon pump (IABP) counterpulsation improves the recovery of left ventricular (LV) systolic function after reperfused acute myocardial infarction (AMI). METHODS AND RESULTS: Fourteen dogs underwent 90-min coronary artery occlusion followed by reperfusion. Seven animals were randomized to IABP counterpulsation immediately after reperfusion. Tagged, cine, and contrast-enhanced magnetic resonance imaging were used for regional and global LV functional assessment and MI characterization, respectively. Image acquisition was performed at 1 h, 6 h, and 24 h after reperfusion, during which the IABP device was paused. Animals randomized to IABP demonstrated an earlier improvement of LV ejection fraction when compared with controls (25+/-3 vs. 25+/-2% at 1 h, P=0.91; 36+/-3 vs. 26+/-2% at 6 h, P=0.015; and 38+/-3 vs. 35+/-1% at 24 h, P=0.34). Regional functional analyses revealed the same behaviour among non-infarcted risk regions, i.e., earlier circumferential systolic strain improvement in the IABP group than in controls (-5.4+/-0.4 vs. -5.3+/-0.5% at 1 h, P=0.86; -12.1+/-1.0 vs. -6.0+/-0.4% at 6 h, P<0.001; and -13.9+/-1.1% vs. -12.8+/-0.6% at 24 h, P=0.40). Importantly, however, the degree of LV functional recovery 24 h after reperfusion was similar whether IABP counterpulsation was used or not. CONCLUSION: IABP counterpulsation accelerates but does not significantly improve the recovery of LV systolic function after reperfused AMI.
Azevedo et al. (Wed,) conducted a rct in reperfused acute myocardial infarction (n=14). Intra-aortic balloon pump (IABP) counterpulsation vs. Control was evaluated on Left ventricular ejection fraction at 24 hours (p=0.34). IABP counterpulsation accelerated early LV ejection fraction improvement at 6 hours (36% vs 26%, P=0.015) but did not significantly improve recovery at 24 hours (38% vs 35%, P=0.34) after AMI.