The Journal of ExtraCorporeal Technology No 56-4 | Page 14

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

Table 1 . Patient demographics for aortic cross-clamp time greater than 90 min .

Continuous variables are expressed median ( IQR ), categorical variables are expressed number (%). Abbreviation : HKB – hyperkalaemic blood cardioplegia ; DNC – Del Nido cardioplegia ; BMI – body mass index ; COPD – chronic obstructive pulmonary disease ; PVD – peripheral vascular disease ; NYHA – New York Heart Association ; LVEF – left ventricular ejection fraction .

Table 2 . Subgroup analysis : Patient demographics for aortic crossclamp time greater than 120 min .

Continuous variables are expressed median ( IQR ), categorical variables are expressed number (%). Abbreviation : HKB – hyperkalaemic blood cardioplegia ; DNC – Del Nido cardioplegia ; BMI – body mass index ; COPD – chronic obstructive pulmonary disease ; PVD – peripheral vascular disease ; NYHA – New York Heart Association ; LVEF – left ventricular ejection fraction . theatre , or mortality ( Table 4 ). The DNC had a higher rate of return to theatre for bleeding ( 6 % vs . 2 %).

The median troponin value at time points 6 , 12 , and 72 h postoperatively , the maximum postoperative troponin , area under the curve nor the number of patients with positive troponin profile showed any difference between the two groups ( Table 5 and Figure 2 ), similarly , there was no difference in time to peak troponin ( Table 6 ). Equivalence testing found DNC to be equivalent to HKC for all troponin measures other than peak troponin ( Table 5 )( p = 0.101 ).

Sensitivity analysis

Similar findings were found for the AXC time > 120-minute subgroup with no differences in preoperative characteristics and clinical outcomes ( Tables 2 , 7 , and 8 ). Troponin profiling did demonstrate differences , with the 72 h , maximum postoperative troponin value and the area under the release curve being higher in the DNC group ( p < 0.05 , Table 9 , Figure 3 ). The median troponin profile at 6 and 12 h , and the number of patients with positive troponin profile between cohorts were not different ( Table 6 ). Equivalence testing found DNC to be not equivalent in troponin measures other than for positive troponin profile ( Table 9 ).

Discussion

Del Nido cardioplegia has a well-established safety profile in myocardial ischaemic times of up to 90 min [ 6 ], with current literature providing little consensus on management protocols for extended AXC times and optimal reporting of clinical endpoints [ 13 , 19 , 20 ]. Clinical advantages of DNC compared to HKB are thought to be mediated by lidocaine ’ s inhibition of cardiomyocyte sodium channels , prevention of hypertonic myocardial oedema moderated by mannitol and competitive inhibition of calcium influx by magnesium [ 7 , 21 ]. Comfortable dosing intervals , and advantages over glycaemic control and reperfusion arrhythmias make it a popular alternative for myocardial protection [ 6 ]. The continued reporting of clinical experiences is mandated to build an evidence base upon which practice may evolve .

Our results showed patients receiving DNC had significantly longer ischaemic time compared to the matched HKB group , while demonstrating increased rates of return of sponta-