TNF and myocardial infarction: Among them, metoprolol is a commonly used β-blocker, which improves cardiac impairment in CMVD and reduces myocardial infarct size to improve microcirculation.In basic research (56), metoprolol has been found to have anti-inflammatory effects, inhibiting the expression of inflammatory cytokines such as IL-1β, IL-6 and tumor necrosis factor-α (TNF-α), inhibiting neutrophil migration and penetration, thereby alleviating MIRI (57).