The Journal of ExtraCorporeal Technology No 56-4 | Page 16

154 M . Szpytma et al .: J Extra Corpor Technol 2024 , 56 , 149 – 158

Table 5 . Post-operative median troponin profiles for greater than 90 min aortic cross-clamp time .

Continuous variables are expressed median ( IQR ), categorical variables are expressed number (%). Abbreviations : HKB – hyperkalemic blood cardioplegia ; DNC – Del Nido cardioplegia ; AUC – area under curve .

Table

6 . Postoperative peak troponin time cardioplegia type . as a function of Q4

Figure 2 . Box and whisker plot for Troponin profile based on cardioplegia strategy for greater than 90-minute ischaemic time . Solid middle bar is the median , top and bottom of box the 75th and 25th percentile , with upper and lower adjacent values .

difference in post-operative troponin T profile [ 10 , 13 ], while Willekes [ 18 ] showed lower release of Troponin T their functional assessments showed no differences between DNC and HKB . Other studies comparing DNC and HKB have also shown no difference however are limited by design bias [ 4 , 24 ]. Existing literature reporting lower troponin profiles with DNC has also reflected a concurrent reduction in AXC time [ 13 , 20 ]. By comparison our study included as a variable in our propensity matching AXC time and this may explain troponin equivalence rather than reduction , even though DNC patients experienced longer ischaemic times . Our early ( 6 and 12 h ) troponin T measurements are consistent with previously reported experiences of non-inferiority for DNC [ 5 , 25 ]. Ad et al ., found lower and earlier peak troponin with DNC ; in contrast , Garcia-Suarez et al incorporated more diverse and complex procedures observing an earlier peak (< 12 h ) with DNC [ 5 , 6 ]. In contrast to ours , their dosing strategy was a single 1000 mL induction dose mixed with autologous blood ( 4:1 crystalloid : blood ) followed by 500 mL redosing for ischaemic periods > 90 min or in patients with spontaneous activity [ 6 ].

Abbreviation : HKB – hyperkalaemic blood cardioplegia ; DNC – Del Nido cardioplegia ; post op – postoperative .

Clinical outcomes

Clinical outcomes of DNC in cases with prolonged AXC times and utilising multi-dose strategies varies in the literature [ 9 , 10 , 20 – 22 , 26 ]. Our study demonstrated no difference in postoperative major adverse events including transfusion , IABP use , maximum inotropic duration , myocardial infarction , acute kidney injury , stroke or mortality . There was no difference in minimum haemoglobin suggesting there is no significant haemodilution with DNC . This was replicated in our sub-group analysis which demonstrated equivalence in outcomes ( Table 8 ), in keeping with a large cohort study sub-analysis done by Koda et al and the recently published prospective RCT by Garcia- Suarez et al . however we did find a higher incidence of stroke with DNC [ 6 , 9 ]. In contrast , other cohort studies have demonstrated a higher rate of IABP , stroke , and inotropic support and higher peak postoperative creatinine levels in multi-dose DNC [ 13 , 26 ]. In this report , it is significant that the median number of cardioplegia doses in the 90 min ACX time primary analysis was one therefore inference on multi-dosing may only be based on the sub-analysis .

In the primary analysis the preference for mode of cardioplegia delivery varied among our groups with DNC administered predominantly antegrade ( 75 %) while HKB cardioplegia was delivered by combination antegrade and