Early Short-Term Vagal Nerve Stimulation Attenuates Cardiac Remodeling After Reperfused Myocardial Infarction

BackgroundVagal nerve stimulation (VS) has been suggested to be an effective adjunct to reperfusion therapy in myocardial infarction (MI). However, the effect of VS on left ventricular (LV) remodeling after reperfused MI has not been examined.Methods and ResultsWe investigated the effects of early, brief VS on acute inflammatory reactions (study 1) and chronic LV remodeling (study 2) in a rabbit model of reperfused MI. In study 1, rabbits were subjected to 60-minute coronary artery occlusion followed by reperfusion alone (MI, n = 8) or treated with 24-hour VS (MI-VS, n = 8). At 24 hours after ischemia-reperfusion, MI-VS rabbits showed significantly decreased myocardial infiltration of neutrophils and reduced myocardial expressions of tumor necrosis factor-α and matrix metalloproteinase-8 and -9, compared with MI rabbits. Myocardial expression of interleukin-6 was not affected by VS. In study 2, rabbits were subjected to coronary occlusion and reperfusion alone (n = 16) or treated with VS for 3 days (n = 14). At 8 weeks after ischemia-reperfusion, MI-VS rabbits showed significantly improved LV dysfunction and dilatation, and significantly reduced infarct size, infarct wall thinning, and LV weight compared with MI rabbits.ConclusionEarly, short-term VS attenuates LV remodeling after reperfused MI, which may be associated with suppression of acute inflammatory reactions.