text: HTK (branded as Custodiol® by Essential Pharmaceuticals LLC), has been presented by industry to surgeons as an alternative solution that exceeds other cardioplegias in myocardial protection during cardiac surgery. This claim relies on the single-dose administration of HTK compared with other multidose cardioplegias (MDC), sparing time in the adjustment of equipment during cardioplegia re-administration, allowing greater time to operate and thus a decreased CPB duration. Other benefits include a lower concentration of sodium, calcium, and potassium compared with other cardioplegias with cardiac arrest arising from the deprivation of sodium. Finally, histidine is thought to aid buffering, mannitol and tryptophan to improve membrane stability, and ketoglutarate to help ATP production during reperfusion.
  A 2021 meta-analysis demonstrated no statistical advantage of HTK over blood or other crystalloid cardioplegias during adult cardiac surgery. The only practical advantage of HTK, therefore, is the single-dose administration compared to multi-dose requirements of blood and other crystalloid cardioplegia.