Researchers at the University of Oklahoma found that transcutaneous vagus nerve stimulation (tVNS) significantly improved heart failure with preserved ejection fraction (HFpEF) in mice by reshaping cardiac immune cell populations. HFpEF was associated with an accumulation of pro-inflammatory CCR2+ cardiac resident macrophages expressing Spp1. tVNS reduced these harmful macrophages while boosting protective Igf1 expression in reparative TLF+/MHC2+ macrophages. The benefits depended on intact acetylcholine signaling through α7 nicotinic receptors and cholinergic CD4+ T cells, revealing a neuroimmune pathway linking vagal tone to cardiac repair.
