Modified del Nido cardioplegia is associated with low incidence of low main strong ion difference and hyperchloremia in pediatric patients after cardiac surgery.

PURPOSE: The aims of this study were (1) to determine the associations of cardioplegic solutions with postoperative main strong ion difference (mSID), which is the difference between sodium ion concentration and chloride ion concentration ([Cl-]) and (2) to determine the associations of cardioplegic solutions with markers of organ dysfunction. METHODS: In this retrospective cohort study, patients aged <5 years who underwent cardiac surgery in a tertiary teaching hospital were included. Patients were classified on the basis of the type of cardioplegic solution: modified del Nido cardioplegia (mDNC) and conventional cardioplegia (CC). The effects of mDNC on postoperative mSID and markers of organ functions were examined using propensity-matched analysis. RESULTS: A total of 500 cases were included. mDNC solution was used in 163 patients (32.6%). After propensity score matching, patients in the mDNC group (n = 152) had significantly higher minimum mSID [28 (26, 30) mEq/L vs. 27 (25, 29) mEq/L, p = 0.02] and lower maximum [Cl-] [112 (109, 114) mEq/L vs. 113 (111, 117) mEq/L, p < 0.001] than patients in the CC group (n = 304). The incidences of low mSID and hyperchloremia in the mDNC group were significantly lower than those in the CC group (63.8 vs. 75.7%, p = 0.01 and 63.2 vs. 79.3%, p < 0.001, respectively). There was no significant difference in the incidence of postoperative acute kidney injury and B-type natriuretic peptide level between the two groups. CONCLUSION: The use of modified del Nido cardioplegia may reduce the incidence of abnormal mSID and hyperchloremia compared with the use of a chloride-rich cardioplegic solution.

Comparison of Bretschneider HTK and Blood Cardioplegia (4:1): A Prospective Randomized Study.

BACKGROUND: We compared the effect of intermittent blood and histidine-tryptophan-ketoglutarate (HTK) solution of Bretschneider on myocardial histopathology and perioperative outcome. METHODS: Forty adult cardiac surgery patients were grouped into two (n = 20 for each): (1) Intermittent blood cardioplegia (IBC): had repeated cold 4:1 blood cardioplegia and (2) HTK: had a single dose of cold HTK for cardioprotection. Creatine kinase (CK)-MB, Troponin-I (cTn-I), pH, and lactate were studied in coronary sinus blood before and after aortic cross-clamping (AXC) and systemic blood at postoperative 6th, 24th, and 48th hours. Myocardial biopsy was performed before and after AXC for light microscopy. Vacuolation, inflammation, edema, and glycogen were graded semiquantitatively (from 0 to 3). The myocardial apoptotic index was evaluated via the terminal deoxynucleotidyl transferase dUTP nick end labeling. RESULTS: There were no differences in perioperative clinical outcomes between the groups. The coronary sinus samples after AXC were more acidotic (7.15 ± 0.14 vs. 7.32 ± 0.07, p = 0.001) and revealed higher CK-MB (21.0 ± 12.81 vs. 12.60 ± 11.80, p = 0.008) in HTK compared with IBC. The HTK had significantly a higher amount of erythrocyte suspension intraoperatively compared with IBC (0.21 ± 0.53 vs. 1.68 ± 0.93 U, p = 0.001). Microscopically, myocardial edema was more pronounced in HTK compared with IBC after AXC (2.25 ± 0.91 vs. 1.50 ± 0.04, p = 0.013). While a significant increase in the apoptotic index was seen after AXC in both groups (p = 0.001), no difference was detected between the groups (p = 0.417). CONCLUSION: IBC and HTK have a similar clinical outcome and protective effect, except for more pronounced myocardial edema and increased need for intraoperative transfusion with HTK.

[Clinical, biochemical and histological indicators of Del Nido cardioplegia efficacy in patients with severe myocardial hypertrophy]. / Klinicheskie, biokhimicheskie i gistologicheskie pokazateli effektivnosti kardioplegicheskogo rastvora Del Nido u patsientov s vyrazhennoi gipertrofiei miokarda.

OBJECTIVE: To evaluate the effectiveness of two cardioplegia techniques in patients with severe myocardial hypertrophy undergoing septal myectomy or aortic valve replacement. MATERIAL AND METHODS: A comparative pilot prospective single-center randomized study included 46 patients between 2022 and 2023. Patients were randomized into 2 groups: Del Nido (n=23) and Custodiol (n=23). We analyzed perioperative echocardiography data, troponin I at several time points, perioperative complications and histological data. RESULTS: Both groups were comparable in time of myocardial ischemia, cardiopulmonary bypass, duration of anesthesia and surgery (p>0.05). The maximum ischemia time in the Del Nido group was 84 min. The same group showed significantly higher percentage of spontaneous rhythm recovery (65.2% vs. 30%, p=0.008). None patient required mechanical support, high-dose inotropes or vasopressors. Troponin I in 2 hours after cardiopulmonary bypass (p=0.415), 12 (p=0.528) and 24 hours after admission to the intensive care unit (p=0.281) were similar in both groups. No significant difference was found in ventilation time, ICU- and hospital-stay. CONCLUSION: Del Nido cardioplegia has some advantages compared to Custodiol and does not lead to perioperative complications in case of aortic cross-clamping time <90 min in patients with myocardial hypertrophy.

Non-selective Del Nido and St Thomas cardioplegia in adults: analysis of early clinical experience using propensity matching.

BACKGROUND: Del Nido cardioplegia (DNC) is a single-dose, high potassium, low-volume cardioplegia solution that has grown in favor recently. However, the use of DNC in the Asian population may be associated with certain challenges. METHODS: Between January 2017 and April 2022, DNC was used for myocardial protection in this single-center retrospective study. In total, 5731 patients underwent open heart surgeries, where 310 patients received DNC for single or multiple procedures. A total of 307 pair of propensity-matched patients from DNC and cold blood St. Thomas cardioplegia (STC) were compared. RESULTS: In total, 5085 patients with STC and 310 patients with DNC from the cohort were matched, reflecting the initial group sizes before propensity matching. About 307 patient pairs were included in the final analysis after propensity matching with the interest variables. In the STC group, the requirement for an immediate postoperative intra-aortic balloon pump (IABP) was significantly higher [18 (5.9%) in DNC versus 28 (9.1%) in STC, p = 0.021]. A 30-day mortality was comparable between the DNC and STC groups (2.9% versus 3.3%, p = 1.00). Major adverse cardiac events (MACE) (2.6% versus 3.6%, p = 0.648) showed no difference between the groups. In both single and multiple procedure subgroups, there were no statistically significant differences in 30-day mortality and MACE incidences when comparing STC and DNC. CONCLUSION: The use of DNC in adults is acceptable and adaptable. Comparable clinical outcomes between STC patients and DNC were revealed by our investigation. There were no appreciable differences in 30-day mortality or MACE despite the STC group having a much higher need for immediate postoperative IABP.

del Nido versus hematic cardioplegia in minimally invasive aortic valve surgery.

BACKGROUND: The quality of a myocardial protection of a single-dose del Nido cardioplegia versus multiple dose blood-based cardioplegia on myocardial injury, outcomes and operative times in patients undergoing minimally invasive aortic valve replacement is basically unreported. METHODS AND RESULTS: Preoperative and post-operative data, as well as technical details from isolated minimally invasive aortic valve replacements, performed using single-dose or multiple-dose cardioplegia were prospectively collected and retrospectively analysed. A total of 110 patients undergoing minimally invasive valve replacements at our institution composed two groups: 55 patients in the blood cardioplegia group (BloCa) and 55 in the del Nido group (DeNiCa). The two-matched groups were comparable in terms of preoperative variables. In the DeNiCa group, there was a statistically significant less need for cardiac defibrillation after aortic cross-clamp release (p < 0.001). Moreover, the BloCa group received intraoperatively more blood transfusions (p = 0.001) and more insulin administration for higher glucose levels (p < 0.001). The BloCa group showed higher intraoperative lactate levels (p = 0.01). Need for post-operative inotropic and vasoactive support, Creatine Kinase-MB levels after 6 and 12 h, onset of post-operative atrial fibrillation and length of stay were similar. No deaths occurred in neither groups. CONCLUSION: Single-dose del Nido cardioplegia in the setting of minimally invasive aortic surgery seems to offer adequate myocardial protection, comparable to multiple dose hematic cardioplegia. It has been documented a lower peri-operative need of defibrillation after cross-clamp release, lactate- and glucose peak values, as well as less blood transfusions compared to blood cardioplegic strategy.

del Nido versus blood cardioplegia in adult cardiac surgery: a meta-analysis.

AIMS: Initially developed for myocardial protection in immature cardiomyocytes, del Nido cardioplegia has been increasingly used over the past decade in adult patients. Our aim is to analyse the results from randomized controlled trials and observational studies comparing early mortality and postoperative troponin release in patients who underwent cardiac surgery using del Nido solution and blood cardioplegia. METHODS: A literature search was performed through three online databases between January 2010 and August 2022. Clinical studies providing early mortality and/or postoperative troponin evaluation were included. A random-effects meta-analysis with a generalized linear mixed model, incorporating random study effects, was implemented to compare the two groups. RESULTS: Forty-two articles were included in the final analysis for a total of 11 832 patients, 5926 of whom received del Nido solution and 5906 received blood cardioplegia. del Nido and blood cardioplegia populations had comparable age, gender distribution, history of hypertension and diabetes mellitus. There was no difference in early mortality between the two groups. There was a trend towards lower 24 h [mean difference -0.20; 95% confidence interval (CI) -0.40 to 0.00; I2 = 89%; P = 0.056] and lower peak postoperative troponin levels (mean difference -0.10; 95% CI -0.21 to 0.01; I2 = 0.87; P = 0.087) in the del Nido group. CONCLUSION: del Nido cardioplegia can be safely used in adult cardiac surgery. The use of del Nido solution was associated with similar results in terms of early mortality and postoperative troponin release when compared with blood cardioplegia myocardial protection.

Outcomes of del Nido cardioplegia after surgical aortic valve replacement and coronary artery bypass grafting.

OBJECTIVE: The use of del Nido cardioplegia (DNC) was initially adopted in the field of pediatric cardiac surgery. Several studies in adult patients suggested there were no differences in early postoperative outcomes as compared to blood-based cardioplegia. We sought to evaluate the impact of DNC as compared to modified Buckberg cardioplegia (BC) on early postoperative outcomes in patients undergoing surgical aortic valve replacement with and without coronary artery bypass grafting (SAVR ± CABG). METHODS: All SAVR ± CABG procedures were switched from BC to DNC at our institute in 2012. We compared outcomes of BC (November 2007-October 2012; n = 1037) with DNC (November 2012-December 2017; n = 1067). Significant baseline differences were observed between the two groups and such differences were adjusted via inverse propensity treatment weighting. RESULTS: After adjustment, SAVR ± CABG patients who received DNC required longer aortic cross-clamp times, while postoperative peak troponin I and creatinine kinase-MB isotype were significantly lower in the BC group. Length of hospital and intensive care unit stay were significantly shorter in the DNC group. The incidence of postoperative complications was lower in the DNC cohort. Thirty-day mortality rate was significantly lower in the DNC group (3.0% vs 4.9%, p = 0.002). CONCLUSIONS: The use of DNC cardioplegia in our cohort of adult patients who underwent SAVR ± CABG was safe and associated with improved postoperative outcomes. However, the use of DNC may be associated with higher degrees of myocardial injury.

Single-Dose St. Thomas Versus Custodiol® Cardioplegia for Right Mini-thoracotomy Mitral Valve Surgery.

OBJECTIVE: Custodiol® and St. Thomas cardioplegia are widely employed in mini-thoracotomy mitral valve (MV) operations. One-dose of the former provides 3 h of myocardial protection. Conversely, St. Thomas solution is usually reinfused every 30 min and safety of single delivery is unknown. We aimed to compare single-shot St. Thomas versus Custodiol® cardioplegia. METHODS: Primary endpoint of the prospective observational study was cardiac troponin T level at different post-operative time-points. Propensity-weighted treatment served to adjust for confounding factors. RESULTS: Thirty-nine patients receiving St. Thomas were compared with 25 patients receiving Custodiol® cardioplegia; cross-clamping always exceeded 45 min. No differences were found in postoperative markers of myocardial injury. Ventricular fibrillation at the resumption of electric activity was more frequent following Custodiol® cardioplegia (P = .01). CONCLUSION: Effective myocardial protection exceeding 1 h of ischemic arrest can be achieved with a single-dose St. Thomas cardioplegia in selected patients undergoing right mini-thoracotomy MV surgery.

Clinical impact of del Nido cardioplegia in adult cardiac surgery: A prospective randomized trial.

OBJECTIVE: The study objective was to assess the benefits of del Nido cardioplegia compared with cold blood cardioplegia solution in terms of myocardial protection during adult cardiac surgery. METHODS: A total of 474 adult patients undergoing coronary artery bypass grafting, heart valve surgery, thoracic aortic surgery, or combined procedures were randomized to the del Nido cardioplegia group (n = 234) or the cold blood cardioplegia solution group (n = 240) after provided informed consent. The primary end points assessed inotropic support requirements, severe cardiovascular events, and troponin trend within the first 48 hours of intensive care unit stay. Reperfusion arrhythmias, aortic crossclamp and cardiopulmonary bypass times, and other clinical perioperative variables were considered as secondary end points. RESULTS: No statistically significant differences were found regarding postoperative inotropic support requirements or the incidence of severe cardiovascular events. The del Nido cardioplegia group showed a higher return to spontaneous sinus rhythm (P< .001), a lower number of defibrillation attempts (P< .001), and an earlier peak troponin value in the postoperative period. Peak blood glucose levels and intravenous insulin requirements were significantly lower in the del Nido cardioplegia group. We found no significant differences regarding aortic crossclamp or cardiopulmonary bypass time. We did observe a lower incidence of postoperative stroke in the del Nido cardioplegia group (2.6% vs 6.7%; P= .035). CONCLUSIONS: del Nido cardioplegia can be used safely and with comparable outcomes compared with traditional cardioplegia solutions. Additional advantages over glycemic control, reperfusion arrhythmias, and its comfortable redosing interval make del Nido an interesting alternative for myocardial protection in adult cardiac surgery. A significant decrease in postoperative stroke will require further research to shed light on the results of this study. VIDEO ABSTRACT.

Del Nido versus cold blood cardioplegia in adult patients with impaired ejection fraction undergoing valvular and complex heart surgery.

BACKGROUND: There is sparse evidence on the efficacy of del Nido cardioplegia in high-risk patients with reduced ejection fraction undergoing valvular or complex heart surgery, and further investigation is required. METHODS: An institutional registry was searched for patients who underwent valvular or complex heart surgery and had an ejection fraction <40%. Subjects who received del Nido cardioplegia (DNC) and cold blood cardioplegia (CBC) were selected. Propensity matching was performed with age, gender, and number of conducted procedures as matching criteria. A comparative analysis was performed on primary endpoints of the troponin rise and changes in ejection fraction (EF). A composite endpoint of a troponin rise of ≥20× baseline or fall of EF≥5% was assessed in a multivariate analysis. Other perioperative complications are reported. RESULTS: One hundred patients from the DNC group were matched to the 100 patients in the CBC group. There were no differences between groups at baseline. Postoperatively, lower troponin values were observed in the DNC group at 12 hours (median; IQR: 523.2;349.1-740.4 pg/mL vs. 787.6;443.6-1689.0 pg/mL; P=0.016) and 36 hours (median; IQR: 426.1;337.2-492.1 pg/mL vs. 653.7;398.8-1737.5 pg/mL; P=0.044). Fewer patients in the DNC group had a fall in EF≥5% (7% vs. 16%; P=0.046). The multivariable analysis did not reveal a significant predictor of composite endpoint. CONCLUSIONS: In patients with impaired contractility undergoing valvular and complex procedures, the use of del Nido cardioplegia as an alternative to cold blood cardioplegia is associated with lower troponin release and improved preservation of ejection fraction.

Protective Efficacy on Adult Ischemic Myocardium under Bypass: Del Nido vs. St. Thomas Blood Cardioplegia.

PURPOSE: To compare the myocardial protective efficacy of del Nido cardioplegia (DNC) with St. Thomas blood cardioplegia (SBC) in adult cardiac surgery. METHODS: From January to December 2021, all the patients who underwent elective cardiac operation were randomly divided into two cohorts based on the type of cardioplegia: DNC group and SBC group. Three categories of variables were compared: patient demographics, clinical variables, and laboratory variables. RESULTS: A total of 133 patients were enrolled in this study: DNC group, n = 65; and SBC group, n = 68. Except that the volume of cardioplegia administration were obvious less in the DNC group (P <0.01), no significant difference was found in the other postoperative clinical variables (P >0.05). No statistical significance was proved (P >0.05) in postoperative troponin I, creatine kinase, and B-type natriuretic peptide. The malondialdehyde concentration was higher in the SBC group, whether it is at 4 hours (P <0.05) or 24 hours (P >0.05) after operation. At the same two points in time, the change in superoxide dismutase activity was more significant in the SBC group (P <0.05). CONCLUSION: The DNC cardioplegia was safe and effective on adult myocardium protection. The potential antioxidant stress effect in DNC may provide a direction for further improvement on the formula of cardioplegic solution.

Stone heart syndrome after prolonged cardioplegia induced cardiac arrest in open-heart surgery - a pilot study on pigs.

OBJECTIVES: To investigate Stone Heart Syndrome (SHS) as consequence of prolonged ischemic arrest in an experimental study on pigs in regards to onset of SHS and pathological changes. Outcomes defined as aortic cross clamp (ACC) time until onset of SHS and cellular changes characterized by SHS. METHODS: Eight pigs were included to undergo normothermic cardioplegia induced cardiac arrest ranging from 80 to 240 minutes of ACC. Duration of ACC was defined as time from initiation of aortic cross clamping until cessation. Normothermic, cardioplegic solution administered directly into the arterial system, though in a reduced dose compared to clinical practice. Myocardial contracture evaluated by palpation of the myocardium. Biopsies were collected from the left ventricle just after the induction of cardiac arrest and after reperfusion. Biopsies were evaluated for pathological changes indicative of SHS by electron microscopy. RESULTS: Six pigs completed the full trial, while two were lost to bleeding. Pigs undergoing 80 to 120 minutes of ACC regained heart rhythm either spontaneously or after defibrillation. Pigs undergoing more than 180 minutes of ACC had contracted hearts with no electrocardiographic response indicating the development of SHS. Electron microscopy findings after ACC of 80 to 120 minutes showed no or low degrees of cellular changes, whereas pig hearts with more than 180 minutes of ACC showed severe mitochondrial changes, endothelial damage, and shortening of sarcomeres consistent with SHS. CONCLUSION: Development of SHS in pigs was ACC time dependent and solely avoided when ACC was limited to a maximum of 120 minutes.

Re-dosing of del Nido cardioplegia in adult cardiac surgery requiring prolonged aortic cross-clamp.

OBJECTIVES: Few data exist on the use of del Nido cardioplegia in adults, specifically during operations requiring prolonged aortic cross-clamp. In this pilot study, we evaluate outcomes of patients undergoing surgery with cross-clamp time >3 h based on re-dosing strategy, using either full dose (FD; 1:4 blood to crystalloid ratio) or dilute (4:1 blood to crystalloid ratio) solution. METHODS: Consecutive adult patients (>18 years) undergoing cardiac surgery from 2012 to 2018 with cross-clamp time >3 h were reviewed. Patients were excluded if del Nido cardioplegia was not used. Patients were categorized into FD or dilute groups based on re-dosing solution. Propensity score matching was used to control for baseline differences between groups. The primary endpoint was in-hospital mortality. Other outcomes examined included: postoperative mechanical support, arrhythmia, stroke, dialysis and cardiac function. RESULTS: Included for analysis were 173 patients (115 male) with median age of 63.8 (interquartile range 53.9-73.1). Major comorbidities included diabetes (45), cerebrovascular disease (34), hypertension (131), atrial fibrillation (52) and previous cardiac surgery (83). There were 108 patients (62%) who received FD re-dosing, while 65 (38%) received dilute. A greater proportion of patients in the dilute group received retrograde delivery, for both induction (32/108 vs 39/65, P < 0.001) and re-dose (50/108 vs 53/65, P < 0.001). After propensity score matching, in-hospital mortality was not different between groups (6/48 vs 1/48, P = 0.131). There were no differences in rates of postoperative mechanical circulatory support, stroke, left ventricular ejection fraction or right ventricle dysfunction. CONCLUSIONS: Del Nido cardioplegia has been used in complex cardiac surgery requiring prolonged cross-clamp. Re-dosing can be performed with either FD or dilute del Nido solution with no statistical difference in outcomes.

Modified del Nido versus blood cardioplegia in congenital cardiac surgery.

BACKGROUND: Lactated Ringer-based del Nido cardioplegia has been reported to be safe for acquired cardiac surgery. The original Plasma-Lyte-based solution has been proved for congenital cardiac surgery but its modification has not been adequately examined. We compared the clinical outcomes of congenital cardiac surgery using lactated Ringer-based del Nido cardioplegia versus cold blood cardioplegia. METHODS: Between September 2018 and November 2020, 116 consecutive patients with congenital heart disease undergoing operations with cardioplegic arrest performed by a single surgeon at Faculty of Medicine Siriraj hospital; 66 with modified del Nido solution and 50 with institutional's blood cardioplegia. The patient risk profiles, operative details, mortality rates, care durations, inotrope use, blood transfusion and complications were compared. RESULTS: Preoperative characteristics were similar between groups, including median age (2.5 vs. 3.1 years; p = 0.49), size, and gender. The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery score of 3 to 5 was more prevalent in the del Nido group (24.2% vs. 10%; p = 0.049). There were 4 deaths in the modified del Nido group (risk category score of 4) but none in the cold blood group (p = 0.13). There was no significant difference in median intubation duration, length of intensive care unit stay, and vasoactive medications immediately and 24 h after the operation. The del Nido group required 70 to 100 ml less blood transfusion (p = 0.04). All complications were similar between the two groups. CONCLUSIONS: Clinical outcomes of lactated Ringer-based del Nido cardioplegia were comparable to those of blood cardioplegia in congenital cardiac surgery.

Serial ultrastructural evaluation of myocardial ischemic injury after infusion of del Nido cardioplegia in the human heart.

OBJECTIVES: The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope. METHODS: Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = irreversible). RESULTS: At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and irreversible injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic injury score of mitochondria and ischemic time (P < .001). Most nuclei showed moderate to severe ischemic injury at every time point (61.0%-85.2%). A significant linear correlation was also found between the average ischemic injury score of nuclei and ischemic time (P < .001). CONCLUSIONS: Myocardial ischemic injury progresses gradually, and irreversible ischemic injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.

Comparison of del Nido and histidine-tryptophan-ketoglutarate cardioplegic solutions in minimally invasive cardiac surgery.

OBJECTIVE: We examined the safety and efficacy of del Nido cardioplegic solution compared with histidine-tryptophan-ketoglutarate cardioplegic solution in minimally invasive cardiac surgery. METHODS: Patients who underwent minimally invasive cardiac surgery using del Nido or histidine-tryptophan-ketoglutarate from 2015 to 2019 were enrolled. Various clinical outcomes were compared between the groups. Postoperative laboratory findings including the levels of electrolytes, cardiac enzymes (creatine kinase-MB and troponin I), and serial blood lactate were also measured and compared. Based on 28 baseline covariates, propensity score matching was performed to reduce selection bias. RESULTS: Among 766 patients, del Nido and histidine-tryptophan-ketoglutarate were used in 330 patients (43.1%) and 436 patients (56.9%), respectively. There were no significant intergroup differences in postoperative clinical outcomes and early adverse outcomes among 228 pairs of propensity score-matched patients. Immediate postoperative sodium levels were within the normal range in both groups without a significant difference (P = .50). However, peak creatine kinase-MB (median, 31.9 vs 37.7 ng/mL, P = .026) and troponin I (6.9 vs 9.1 ng/mL, P = .014) levels were significantly lower in the del Nido group. Linear regression analysis revealed a significant association between the peak cardiac enzyme levels and the cardiac ischemic time depending on the cardioplegia type, with lower cardiac isoenzymes for del Nido over histidine-tryptophan-ketoglutarate (P < .001) until the crossover point at the cardiac ischemic time over 100 minutes. CONCLUSIONS: In comparison with histidine-tryptophan-ketoglutarate solution, del Nido solution seems to have acceptable safety and efficacy with good myocardial protection in minimally invasive cardiac surgery. Further studies focusing on complex surgeries requiring longer cardiac ischemic time are needed.