Abstract 12925: The Neuro-Mechanical Unloading for Acute Myocardial Infarction Strikingly Reduces the Infarct Size and Prevents Heart Failure in the Long Term (Best of Basic Science Abstract)

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Introduction: Although widespread practice of early coronary intervention has reduced the acute phase mortality in myocardial infarct (MI), the late development of heart failure remains increasing at an alarming rate. Left ventricular (LV) assist device (VAD) unloads the heart, thereby decreases oxygen consumption. Vagal nerve stimulation (VNS) exerts a powerful anti-infarct effects. Hypothesis: We hypothesized that the combination of short term VAD (mechanical unloading) and VNS (neural unloading) for the ischemia/reperfusion (IR) model would prevent the late development of heart failure. Methods: In 24 dogs, we occluded the left anterior descending coronary artery for 180min and then reperfused. We unloaded LV with transvascular VAD (Impella®). We administrated transvascular VNS with a pacing catheter in the superior vena cava (10Hz). The neuro-mechanical unloading started at 90min after the onset of ischemia and ended at 60min after reperfusion. We allocated dogs into 4 groups, IR (n=7), VAD (n=6), VNS (n=4) and VAD+VNS (n=5) and compared the infarct size and cardiac function one month after IR. Results: LVAD+VNS normalized LV end-systolic elastance (IR: 6.1±3.3, VAD: 8.1±1.3, VNS: 10.6±4.5, VAD+VNS: 14.9±2.8 mmHg/ml, p<0.05) and maximally lowered LV end-diastolic pressure (EDP) (16.8±6.4, 6.4±1.5, 5.3±3.1, 3.7±0.4 mmHg, p<0.05). NT-proBNP paralleled the changes in LVEDP (3712±1141, 1728±348, 1507±511, 1059±397 mmHg, p<0.05), supporting nearly normalized cardiac function. VAD+VNS strikingly reduced the infarct size by more than 70% (p<0.05, Figure). Conclusions: The combination of short term VAD and VNS prior to reperfusion markedly reduces the infarct size and prevents the late development of heart failure. The fact that we can deliver both VAD and VNS transvascularly indicates that the neuro-mechanical unloading therapy is clinically applicable and would improve the long term survival in post-MI patients with coronary intervention.