“…9 Alternatively, heart preservation using continuous perfusion can provide the energy required for metabolism during cold ischemic heart preservation, remove the acidic metabolites, and prolong the time of donor heart preservation by 8-10 h. 10,11 However, continuous perfusion has several shortcomings, such as inducing tissue edema, increased vascular edema, and increased endothelial injury, in addition to the requirement of a special perfusion device and large volumes of preservation solution because of the elongated preservation time, 12-14 some of which cannot be overcome even with retrograde perfusion. 15 Therefore, intermittent perfusion at low temperature may be more advantageous than continuous perfusion 16 as it not only provides metabolic substrates and rinses metabolites as with continuous perfusion but also reduces the total volume of perfusion solution required and decreases the myocardial edema and vascular endothelial injury. However, because both continuous perfusion 15 and intermittent perfusion are affected by perfusion pressure, velocity, and time, [17][18][19] further studies are necessary to identify the parameters for optimal myocardial protection to prevent endothelial cell and smooth muscle cell damage, resulting in increased capillary permeability and release of vasoactive substances and subsequent vasospasm, insufficient microvascular perfusion, and cardiac dysfunction soon after transplantation as well as long-term outcomes (e.g., chronic cardiac allograft vasculopathy).…”