B . Ali et al .: J Extra Corpor Technol 2024 , 56 , 84 – 93 85
However , each formulation has some undesirable effects , especially in pediatric cases [ 6 ]. In the early 1990s , researchers from the University of Pittsburgh developed a cardioplegia solution specifically tailored to meet the unique needs of immature hearts . Their focus was on addressing intracellular calcium , myocardial high-energy phosphates , lactate production , and intracellular buffering . Subsequently , Dr . Pedro Del Nido further refined and modified the solution for myocardial protection , with a particular emphasis on immature pediatric myocardium . Boston Children ’ s Hospital has been successfully employing this solution for more than two decades now , with positive outcomes in congenital cases . Since 2003 , this solution has also been used effectively in adult cardiac surgery . The solution ’ s efficacy and safety make it a promising option for cardiac surgery in both adult and pediatric populations [ 7 , 8 ]. Del Nido cardioplegia has also been proven effective in adult minimal invasive cardiac surgeries and acquired cases ( coronary artery bypass , valvular , and combined surgeries ) [ 9 – 11 ].
Mick and Sevuk et al . have found that del Nido solution , when compared to other cardioplegias or when modified with different additives , can have beneficial effects over traditional cardioplegia [ 12 , 22 ]. Another study by Karaarslan et al . showed that del Nido cardioplegia is an effective and cost- efficient option for coronary surgery with similar clinical outcomes to traditional blood cardioplegia [ 13 ]. Lactated Ringer-based del Nido solution can also provide myocardial protection comparable to the blood cardioplegia strategy [ 14 ]. Another study has explored modifications to del Nido cardioplegia , with promising results in preserving LV ( Left Ventricle ) function and inducing spontaneous sinus rhythm return [ 15 , 16 ]. A meta-analysis suggests that del Nido cardioplegia may be associated with lower perioperative mortality than Custodial or Blood Cardioplegia in adult patients , but the risk of atrial fibrillation may lower with Custodial Histidine-tryptophan-ketoglutarate ( HTK ) [ 17 ]. However , there has been no study comparing the modified version of the del Nido cardioplegia solution to other modified versions of the del Nido cardioplegia solution , making this study the first of its kind to our knowledge . At our center ( Shahid Faghihi Hospital ), we use a modified version of del Nido cardioplegia called routine del Nido cardioplegia solution ( rdNCS ) for both adult and pediatric cardiac surgeries . For the past 8 years , we have been using 0.9 % normal saline as the baseline solution instead of Plasma Lyte A , which is limitedly available in certain Asian countries , including Iran .
Therefore , this study aims to provide more definitive evidence on the superiority of one solution over others based on various outcomes , including Creatine Kinase-MB ( CK-MB ) level , Troponin level , bypass time , clamp time , incidence of ventricular fibrillation , postoperative atrial flutter , atrial fibrillation , ventilation support time , Intensive Care Unit ( ICU ) stay , and perioperative mortality . The study is particularly focused on the use of del Nido cardioplegia as a myocardial protection solution for adult surgeries and the composition of the solution . In addition , this study also hypothesized that the Ringer lactatebased del Nido cardioplegia solution performs better than normal saline and plain Ringer-based del Nido cardioplegia solutions . The findings of this study could contribute to clinical practice and improve patient outcomes in CABG surgeries .
Methods and materials Trial design and setting
This study was conducted at a single tertiary care hospital in Iran from February 1 to June 20 , 2023 . This was a prospective , double-blinded , randomized , parallel-group clinical trial .
Participants
A total of 187 adult patients were evaluated for eligibility , of which 120 met the inclusion criteria . Patients more than 18 years old with a minimum ejection fraction of 30 %, diagnosed with triple vessel coronary artery disease , and scheduled for on-pump elective isolated CABG surgery were included and randomly assigned to three groups . The Control Group received rdNCS made with normal saline ( n = 40 ). Intervention Group A received a modified del Nido Cardioplegia Solution ( rldNCS ) made with Ringer lactate ( n = 40 ). Intervention Group B received a modified del Nido Cardioplegia Solution ( prdNCS ) made with plain Ringer ( n = 40 ). The effectiveness of these interventions was evaluated through follow-up assessments of the participants .
Procedure
All patients underwent the standard protocol for general anesthesia , with routine drugs used for induction and maintenance . The surgical approach involved a median sternotomy along with graft preparation and a cardiopulmonary bypass was established by connecting an arterial cannula to the ascending aorta for arterial limb access , and a two-stage cannula was connected to the right atrium for venous drainage via the venous limb . The cardioplegic arrest was induced by cardioplegia after aortic cross-clamping at the core body temperature of 32 – 34 ° C .
Intervention
The cardioplegic solutions were given at the aortic root after cross-clamping for myocardial protection via the antegrade route using standardized aseptic techniques routinely used as per hospital policy . The solutions were prepared by the perfusionist according to the instructions present in a sealed envelope . The rdNCS made with normal saline was modified at the service moments before their administration to the myocardium via aortic root , and either the Ringer lactate ( modified del Nido I or Intervention A ) or plain Ringer ’ s ( modified del Nido II or Intervention B ) used as the crystalloid baseline solution per randomization received in an opaque envelope . The autologous blood and crystalloid ratio were 1:4 . The rdNCS composition comprises normal saline 0.9 % 800 mL ( Baseline Solution ), containing Sodium ( Na +) 154 mEq / L , Chloride ( Cl� ) 154 mEq / L , and Tonicity 308 mOsm / L , with a pH of approximately 5.5 . This solution also includes additives such as Mannitol 20 % 16.3 mL , Magnesium sulfate 50 % 4 mL , Sodium bicarbonate 8.4 % ( 1 mEq / mL ) 20 mL , Potassium