Del Nido versus cold crystalloid cardioplegia for myocardial protection during ventricular septal defect repair in children under one year of age: a prospective randomized trial
Authors: Lazarkov Petr V. , Orekhova Ekaterina N. , Khlynova Olga V. 
Published: February 2024

Rationale: The choice of strategy for myocardial protection during procedures with cardiopulmonary bypass and cardioplegic arrest in children is not regulated by clinical guidelines due to insufficient data from clinical studies. The issue of methods to assess myocardial injury remains unresolved.
Aim: To assess the frequency and specifics of the development of intraoperative myocardial injury syndrome in children of the first year of life with ventricular septal defect depending on the strategy for cardioplegia.
Materials and methods: In a single center, prospective, randomized controlled trial we compared two cardioplegia strategies during surgical closure of ventricular septal defect in infants aged from 1 to 12 months: del Nido blood cardioplegia (n = 102) and cold crystalloid cardioplegia with Custodiol solution (n = 102). The primary endpoint was a persistent over 10-fold increase above the upper limit of the normal in the plasma concentration of high-sensitivity troponin I at 6 hours after surgery persisting after 24 hours. The secondary combined endpoint was myocardial damage verified by persistent increase in troponin I level more than 10-fold above the upper limit of the normal, persisting at 6 and 24 hours, accompanied by new pathological Q waves, acute complete left bundle branch block, abnormalities of the end part of the ventricular complex on the electrocardiography (ST segment elevation 1 mm or ST depression of 1 mm in more than 2 adjacent leads), and a decrease in the global longitudinal strain of the left ventricle by 50% from the initial value at 6 hours after surgery.
Results: In 53/204 (26%) patients, the increase in troponin I persisted at 24 hours after the surgery and was associated with electrocardiography abnormalities, changes in the parameters of left ventricle longitudinal mechanics, and in some cases required greater inotropic support. By the end of the 1st postoperative 24 hours, the longitudinal strain of the left ventricle showed more negative changes over time in the Custodiol group compared to that in the del Nido group (-10 [-14.1; -6.27] versus -14.8 [- 16.5; -10]%; p 0.0001). The same was true for the left ventricle global strain rate (-0.71 [-0.9; -0.52] s-1 in the del Nido group and -0.57 [-0.760; - 0.44] s-1 in the Custodiol group; p = 0.0049). The primary endpoint was achieved by 21 (20.6%) and 55 (53.9%) patients in the del Nido and Custodiol groups, respectively (p = 0.032). The combined endpoint in the Custodiol group was achieved by 34 (33.3%) versus 19 (18.6%) patients in the del Nido group (p = 0.049, χ2 = 3.875, DF = 1, φ = 0.191).
Conclusion: Del Nido blood cardioplegia compared to cold crystalloid cardioplegia with Custodiol has advantages in terms of preventing intraoperative myocardial damage and minimizing its severity. When assessing myocardial damage, such indicators as left ventricle global longitudinal strain and left ventricle global strain rate are informative, along with an increase in the troponin I level.