Custodiol-HTK Solution as a Cardioplegic Agent- A Prospective Non-Inferiority Randomized Clinical Trial

Custodiol HTK (histidine-tryptophan-ketoglutarate) cardioplegia: One liter of HTK solution (Custodiol; Koehler Chemi, Alsbach-Haenlien, Germany) contains the following components: 15 mmol/L sodium chloride, 9 mmol/L potassium chloride, 4 mmol/L magnesium chloride, 18 mmol/L histidine hydrochloride, 180 mmol/L histidine, 2 mmol/L tryptophan, 30 mmol/L mannitol, 0.015 mmol/L calcium chloride, 1 mmol/L potassium hydrogen 2-ketoglutarate, osmolarity 310 mOsm/kg, pH 7.02-7.20.

Custodiol-HTK was delivered to establish and maintain cardiac arrest. After cross-clamping of the aorta approximately 1-2 L of Custodiol-HTK was infused into the ascending aorta over 6-8 minutes. Additional doses of 100-200 ml were administered as needed. Custodiol-HTK was delivered at a temperature of 4°C - 10°C.

Cold Blood Cardioplegia: One liter of cold blood cardioplegic solution, mixed at a ratio of 4:1 per Beaumont standard of care (blood /cardioplegic solution), contains the following in a 500 cc bag of D5W (dextrose 5% in water): 50meq/L potassium chloride, 37.5 meq/L sodium bicarbonate and 7.5 meq/L magnesium sulfate.

After cross-clamping the aorta, at least 1000 mL of a 4:1 mixture of cold blood: cold crystalloid was administered at a pressure of 300 mmHg or less via a twin roller pump. Every 20 minutes an additional > 200 mL was administered as needed. The cardioplegic solution was delivered at a temperature of 4°C - 8°C.