Comparative Effects of Single Dose Cardioplegic Techniques with Different Ischemic Time Protocols
Serdar Gunaydin1, Kevin McCusker2
1City Hospital, University of Health Sciences, Ankara, Turkey, 2New York Medical College, New York, NY, USA
BACKGROUND: This study aims to compare different strategies of del Nido cardioplegia (DNC) compared to histidine-tryptophan-ketoglutarate (HTK) solution in minimally invasive aortic valve replacement (mini-AVR) to discuss the safety level of myocardial protection and rationale for redosing intervals. METHODS: During the period from January 2017 to June 2019, 80 patients undergoing mini-AVR with concomitant procedures were prospectively randomized (N=20 in each group) to receive DNC in every 45, 60 and 90 min (DNC-45, DNC-60, DNC-90) versus HTK for 90 min single strategy as control. All patients received the calculated dose under controlled pressure within the predefined duration (20 mL/kg in 5 to 7 minutes via 80 to 100 mm Hg pressure). Left atrial venting was applied for every case and started as soon as the CPB initiated. Patients receiving additional doses received half dose. Redosing was performed via coronary ostia with specific cannula. Ultrafiltration was employed at the end of CPB for every group until reaching 25% hematocrit level. Sensitive biomarkers (interleukin-6, syndecan-1 and aquaporine-4), in addition to routine biochemistry, were documented at baseline (T1), after cessation of cardiopulmonary bypass (T2), and on the first postoperative day (T3). Transventricular biopsy was sampled at T2. RESULTS: In two patients from DNC-45, two in DNC-60, one in DNC-90 and one in HTK, there was a need for conversion to full sternotomy and were excluded. Two patients in the DNC-90 and one in the HTK group needed earlier redosing (<90 minutes; heart started beating/fibrillation) and were excluded. One patient in the DNC-45 group required a third dose of cardioplegia and was excluded. Perioperative follow-up is summarized in Table (*:p<0.05 vs HTK). Interleukin-6 and syndecan-1 levels in DNC-90 group were statistically higher than control at T2.Syndecan-1 staining at T2 biospy is demonstrated in Figure (DNC-90 is significantly poor). CONCLUSIONS:DNC-45, DNC-60 and HTK provided acceptable myocardial protection. DNC-90 had significantly deranged levels of biomarkers, more arrhythmia/AV block incidence resulting in more extended ICU stay indicating inappropriate cellular protection up to 90 min ischemic time.