Pro: In Favor of More Generalized Use of del Nido Cardioplegia in Adult Patients Undergoing Cardiac Surgery

Del Nido cardioplegia for myocardial protection in adult cardiac surgery: a systematic review and update meta-analysis

OBJECTIVE

Although the application of del Nido cardioplegia solution (DNC) in adult cardiac surgery is accumulating, the feasibility and safety of this myocardial protection strategy in adults remains controversial. We aimed to update our previous meta-analysis to determine the myocardial protective effect of DNC versus conventional cardioplegia (CC) in adult cardiac surgery.

METHODS

A comprehensive literature search was performed using PubMed, EMBASE, the Cochrane Library, and International Clinical Trials Registry Platform databases through November 2020.

RESULTS

Thirty-seven observational studies and four randomized controlled trials (RCTs) including 21,779 patients were identified. The DNC group was associated with decreased postoperative cardiac enzymes [troponin T (cTnT) and creatine kinase-MB (CK-MB)] [standardized mean differences (SMD): -0.59, 95% confidence interval (CI): -0.99 to -0.19, p = 0.004], cardiopulmonary bypass (CPB) time (MD: -9.31, 95% CI: -13.10 to -5.51, p < 0.00001), aortic cross-clamp (ACC) time (MD: -7.20, 95% CI: -10.31 to -4.09, p < 0.00001), and cardioplegia volume (SMD: -1.95, 95% CI: -2.46 to -1.44, p < 0.00001). Intraoperative defibrillation requirement was less in the DNC group [relative risk (RR): 0.50, 95% CI: 0.33 to 0.75, p = 0.0007]. The pooled analysis revealed no significant difference in operative mortality among the patients assigned to DNC and those undergoing CC.

CONCLUSION

In adult cardiac surgery, compared to CC, myocardial protection used with DNC yield similar or better short-term clinical outcomes. More high-quality trials and RCTs reflecting long-term follow-up morbidity and mortality are required in the future to confirm these findings.

Del Nido versus warm blood cardioplegia in adult patients with a low ejection fraction

Background

Del Nido cardioplegia was recently introduced to adult cardiac surgery with encouraging results. The effect of Del Nido cardioplegia in patients with low ejection fraction (EF) has not been thoroughly evaluated. The objective of this study was to assess the safety of Del Nido cardioplegia in adult patients with low EF compared to intermittent warm blood cardioplegia.

Results

During 2018 and 2019, 73 adult patients with an EF of ≤ 40% underwent cardiac surgery using Del Nido cardioplegia. The patients were compared to a historical cohort of consecutive patients with low EF who had intermitted warm blood cardioplegia (n = 81). Patients who had Del Nido cardioplegia had significantly lower EuroSCORE II (2.73 (1.7–4.1) vs. 4.5 (2.4–7.4), P = 0.004). There were no differences in creatinine clearance and preoperative echocardiographic data between the groups. Cardiopulmonary bypass and cross-clamp times were non-significantly lower with Del Nido cardioplegia. There were no differences in stroke and postoperative echocardiographic data between the groups. No hospital mortality was reported in both groups. Peak troponin levels were significantly higher in patients who had Del Nido cardioplegia (0.88 (0.58–1.47) vs. 0.7 (0.44–1.01) ng/dL; P = 0.01); however, after multivariable regression analysis, cardiopulmonary bypass time was the only predictor of postoperative troponin level (coefficient 0.005 (95% CI: 0.003–0.008); P < 0.001). ICU stay was significantly longer in patients who had Del Nido cardioplegia (4 (3–6) vs. 2(1–4) days, P < 0.001), while postoperative hospital stay did not differ between the groups. After multivariable regression, the use of intermittent warm blood cardioplegia was significantly associated with shorter ICU stay (coefficient − 1.80 (95% CI − 3.06 – -0.55); P = 0.01).

Conclusions

Prolonged ICU was reported with Del Nido cardioplegia; however, there were no differences in the duration of hospital stay and the clinical outcomes between the groups. Despite the proven efficacy of intermittent warm blood cardioplegia, the use of Del Nido cardioplegia might be safe in patients with low EF.

Myocardial protection in cardiac surgery: Del Nido versus blood cardioplegia

Objectives:

del Nido cardioplegia which was traditionally used for myocardial protection in pediatric congenital heart surgery is now being extensively utilized in adult cardiac surgery. The aim of this study was to compare the safety and efficacy of del Nido cardioplegia (DNC) with blood cardioplegia (BC).

Materials and Methods:

This is a historical cohort study using secondary data. Two hundred and eighty six patients who underwent coronary artery bypass graft (CABG) or valve surgery were included. They were divided into 2 matched cohorts of which 143 patients received BC and 143 patients received DNC.

Results:

There was no difference in cardiopulmonary bypass time (P = 0.516) and clamp time (P = 0.650) between the groups. The redosing of cardioplegia was significantly less for DNC (1.13 vs. 2.35, P = <0.001). The post bypass hemoglobin was higher for DNC (9.1 vs. 8.7, P = 0.011). The intraoperative and postoperative blood transfusion was comparable (P = 0.344) (P = 0.40). The incidence of clamp release ventricular fibrillation (P = 0.207) was similar. The creatine kinase-MB isotype levels for the CABG patients were comparable on all 3 days (P = 0.104), (P = 0.106), and (P = 0.158). The postoperative left ventricle ejection fraction was lesser but within normal range in the DNC group (53.4 vs. 56.0, P = <0.001). The duration of ventilation (P = 0.186), ICU days (P = 0.931), and postoperative complications (P = 0.354) were comparable. There was no 30-day mortality or postoperative myocardial infarction in both the groups.

Conclusion:

DNC provides equivalent myocardial protection, efficacy, and surgical workflow and had comparable clinical outcomes to that of BC. This study shows that DNC is a safe alternate to BC in CABG and valve surgeries.

Clinical outcomes of single-dose cardioplegia in high-risk coronary bypass

BACKGROUND

Despite the increasing popularity of single-dose cardioplegia techniques in coronary artery bypass grafting, the time window for successful reperfusion remains unclear. This study aimed to compare different cardioplegic techniques based on early and 30-day clinical outcomes via thorough monitoring.

METHODS

This prospective cohort study included high-risk patients undergoing coronary artery bypass grafting and receiving 3 different types of cardioplegia between January 2017 and June 2019. Group 1 (n = 101) had a single dose of del Nido cardioplegia, group 2 (n = 92) had a single dose of histidine-tryptophane-ketoglutarate, and group 3 (n = 119) had cold blood cardioplegia. Patients were examined perioperatively by memory loop recording and auto-triggered memory loop recording for 30 days, with documentation of predefined events.

RESULTS

Interleukin-6 and cardiac troponin levels in group 1 were significantly higher than those in groups 2 and 3. The incidence of predefined events as markers of inadequate myocardial protection was significantly higher group 1, with more frequent atrial fibrillation attacks and more hospital readmissions. The readmission rate was 17.6% in group 1, 9% in group 2, and 8% in group 3.

CONCLUSIONS

Our data demonstrate the long-term efficacy of cardioplegic techniques, which may become more crucial in high-risk patients who genuinely have a chance to benefit from adjunct myocardial protection. Patients given del Nido cardioplegia had a significantly more prominent inflammatory response and higher troponin levels after cardiopulmonary bypass. This group had issues in the longer term with significantly more cardiac events and a higher rehospitalization rate.

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.

A survey of practices during cardiopulmonary bypass in India: An Indian association of cardiovascular and thoracic anesthesiologist endeavor

Context:

Cardiac anesthesiologists play a key role during the conduct of cardiopulmonary bypass (CPB). There are variations in the practice of CPB among extracorporeal technologists in India.

Aims:

The aim of this survey is to gather information on variations during the conduct of CPB in India.

Settings and Design:

This was an online conducted survey by Indian College of Cardiac Anaesthesia, which is the research and academic wing of the Indian Association of Cardiovascular Thoracic Anaesthesiologists.

Subjects and Methods:

Senior consultants heading cardiac anesthesia departments in both teaching and nonteaching centers (performing at least 15 cases a month) were contacted using an online questionnaire fielded using SurveyMonkey™ software. There were 33 questions focusing on institute information, perfusion practices, blood conservation on CPB; monitoring and anesthesia practices.

Results:

The response rate was 74.2% (187/252). Fifty-one (26%) centers were teaching centers; 18% centers performed more than 1000 cases annually. Crystalloid solution was the most common priming solution used. Twenty-three percent centers used corticosteroids routinely; methylprednisone was the most commonly used agent. The cardioplegia solution used by most responders was the one available commercially containing high potassium St. Thomas solution (55%), followed by Del Nido cardioplegia (33%). Majority of the responders used nasopharyngeal site to monitor intraoperative patient temperature. Antifibrinolytics were commonly used only in patients who were at high risk for bleeding by 51% of responders, while yet, another 39% used them routinely, and 11% never did. About 59% of the centers insist on only fresh blood (<7 days old) when blood transfusion was indicated. The facility to use vaporizer on CPB was available in 62% of the centers. All the teaching centers or high volume centers in India had access to transesophageal echocardiography probe and echo machine, with 51% using them routinely and 38% using them at least sometimes.

Conclusions:

There is a wide heterogeneity in CPB management protocols among various Indian cardiac surgery centers. The survey suggests that adherence to evidence-based and internationally accepted practices appears to be more prevalent in centers that have ongoing teaching programs and/or have high volumes, strengthening the need to devise guidelines by appropriate body to help bring in uniformity in CPB management to ensure patient safety and high quality of clinical care for best outcomes.

Excellent Restoration of Left Ventricular Compliance After Prolonged Del Nido Single-Dose Cardioplegia in an In Vivo Piglet Model

Del Nido cardioplegia (DN) is used in congenital heart surgery and recently in adults, a single dose has been administered. However, the tolerable ischemic time has not been established. The objective is to evaluate the left ventricular (LV) function recovery and accompanying biochemical and histologic markers to clarify the tolerable ischemic time in an in vivo cardiopulmonary bypass (CPB) piglet model. Twenty-one piglets were subjected to either 90 minutes (with or without topical cooling; TC) or 120 minutes (with TC) of global ischemia induced by single-dose DN, while the other 7 served as the control group (CPB only). The CPB temperature was established with a perfusion temperature of 30°C. The LV function recovery was assessed by the percent change in end-systolic elastance (Ees) and the end-diastolic pressure-volume relationship (EDPVR). Creatine kinase-MB (CK-MB) levels and the mitochondrial score were also assessed. LV contractility assessed by %Ees after 90 and 120 minutes of ischemia (89.3 ± 20.6% and 57.9 ± 17.8%) was lower compared with the control group (122.6 ± 35.8%, P = 0.001). Conversely, LV compliance assessed by %EDPVR was preserved in both groups (102.7 ± 28.2% and 88.5 ± 24.0%), which was comparable to the control group (105.8 ± 36.9%, P = 0.531). There was no change in LV contractility after 90 minutes of ischemia with or without TC (89.3 ± 20.6% or 84.8 ± 16.2%, P = 0.657), whereas LV compliance was lower but not statistically different without TC (102.7 ± 28.2% vs 78.0 ± 38.9%). CK-MB and the mitochondrial score were equivalent between all groups. The proposed single-dose ischemic time for redosing is 90 minutes using TC.