Use of del Nido cardioplegia in acute coronary syndrome cases with decreased ejection fraction

BACKGROUND

There has been increasing interest in using del Nido cardioplegia in adult cardiac surgery. However, there is limited evidence for its efficacy in patients with acute coronary syndrome and reduced ejection fraction.

METHODS

This study examined patients with decreased ejection fraction (EF < 40%) who were hospitalized due to acute coronary syndrome and received either del Nido (DN) or cold blood cardioplegia (CB). The patients were matched based on age, gender, myocardial infarction at baseline, and number of conducted surgical procedures. An analysis was conducted on postoperative biomarker release (high-sensitivity troponin T and isoenzyme creatine kinase-MB (CK-MB)), changes in myocardial contractility and perioperative outcomes.

RESULTS

62 pairs of patients with similar baseline characteristics were selected. 51.6% of pairs underwent isolated coronary artery bypass grafting, while 48.4% underwent a complex procedure. Postoperative troponin values did not differ significantly at 12 h (median (IQR): 606.7 (381.4-974.8) pg/mL vs. 552 (231.8-1579.5) pg/mL; p = 0.913), nor did CK-MB (median (IQR): 24.3 (12.6-45.5) ng/mL vs. 23.7 (12.3-49.8) ng/mL; p = 0.972). The postoperative EF was similar between groups (median (IQR): 30% (30-35%) vs. 34% (30-38%); p = 0.323). No difference in perioperative mortality, myocardial infarction, stroke, or composite endpoint was noted. In a multivariate analysis, the cardioplegia protocol did not affect biomarker release or changes in ejection fraction. The first stage of acute kidney injury was more frequent in the CB group (28.5% vs. 9.7%, p = 0.033).

CONCLUSIONS

Both del Nido and cold blood cardioplegia provide adequate cardioprotection in patients with acute coronary syndrome with decreased ejection fraction.

The effect of Del Nido versus custodiol cardioplegia on clinical outcomes and troponin-I changes among pediatrics with tetralogy of fallot undergoing cardiopulmonary bypass

BACKGROUND

Myocardial protection during operations with cardiopulmonary bypass (CPB) and aortic cross clamping is vital. For this purpose, Del Nido (DN) and Custodiol cardioplegia (CC) solutions are used for single-dose cardioplegia in cardiac surgical procedures with CPB. Present study aimed to compare the effects of DN and CC on peri-operative clinical outcomes in pediatrics with Tetralogy of Fallot (TF) undergoing cardiopulmonary bypass.

METHODS

Present randomized clinical trial was performed in two trial groups with parallel design. One group received DN and another group received CC. We assessed circulatory Troponin-I (cTnI) and coronary sinus lactate level as primary outcomes. Secondary outcomes were ventilation time, electrolytes levels, pump time, cross-clamp time and other clinical parameters.

RESULTS

Duration of CPB and cross-clamp were the same in both groups. There were no significant differences in hemodynamic parameters, left ventricular ejection fraction after the surgery and discharge time between the two trial groups. Ventilation time (8.5 vs. 18; p = 0.001), ICU stay, Troponin-I in ICU admission and Coronary sinus lactate level (p = 0.001) were significantly higher among patients of Custodiol group compared to other trial group. Electrolytes Na, Cl and K levels, during CPB, were significantly less in Custodiol group.

CONCLUSION

When used for inducing cardiac arrest during CPB, DN solution offers better maintenance of the electrolyte balance during CPB, and is associated with less circulatory cTnI and coronary sinus lactate level compared with the CC.

Comparison of lactated Ringer's solution and Plasma-Lyte A as a base solution for del Nido cardioplegia: a prospective randomized trial

OBJECTIVES

The use of del Nido cardioplegia has been increasing in popularity for adult cardiac surgery. However, the base solution, Plasma-Lyte A, is not always available in many countries. This prospective randomized controlled trial evaluated myocardial preservation and clinical outcomes when using lactated Ringer's solution (LRS) compared to Plasma-Lyte A as a base solution for del Nido cardioplegia.

METHODS

Adult patients undergoing first-time elective cardiac surgery for acquired heart disease, including isolated coronary artery bypass grafting, isolated valve surgery, combined valve surgery or concomitant coronary artery bypass grafting and valve surgery were randomized to receive either LRS (n = 100) or Plasma-Lyte A (n = 100).

RESULTS

There were no significant differences between the 2 groups in terms of age, comorbidities, Society of Thoracic Surgeons risk score and type of procedures. The primary outcome, postoperative troponin-T at 24 h, was similar in both groups (0.482 vs 0.524 ng/ml; P = 0.464). Other cardiac markers were also similar at all time points. The LRS group had a lower pH (7.228 vs 7.246; P = 0.005) and higher calcium levels (0.908 vs 0.358 mmol/l; P < 0.001) in the delivered cardioplegia, but there were no significant differences in clinical outcomes, such as ventricular fibrillation, left ventricular ejection fraction, inotrope/vasopressor requirement, intra-aortic balloon pump support, intensive care unit stay, hospital stay, atrial fibrillation, red cell transfusion and complications.

CONCLUSIONS

The results suggest that LRS can be used as an alternative to Plasma-Lyte A as the base solution for del Nido cardioplegia, with similar myocardial preservation and clinical outcomes.

Cyclosporine A-enhanced cardioplegia preserves mitochondrial basal respiration after ischemic arrest

BACKGROUND

Mitochondrial permeability transition pore (mPTP) opening plays a crucial role in cell death during ischemia-reperfusion injury (IRI). Cyclosporine A (CsA) inhibits mPTP opening. This study aimed to investigate the effects of CsA treatment during cardioplegia on the mitochondrial function and cardiac IRI.

METHODS

Landrace pigs (52.9 ± 3.7 kg) were subjected to midline sternotomy, cardiopulmonary bypass at 34°C and 90 minutes of cardiac arrest. They received either a single shot of standard 4°C cold histidine-tryptophan-α-ketoglutarate (HTK)-Bretschneider solution (n = 11) or HTK-Bretschneider plus 1.2 mg/L CsA (histidine-tryptophan-α-ketoglutarate plus cyclosporine A (HTK/CsA); n = 11). During reperfusion global left-ventricular function was assessed and myocardial biopsies were harvested at baseline, during ischemia and 45 minutes following reperfusion. High-resolution respirometry and hydrogen peroxide production were measured. Immunohistochemical stainings for apoptosis-inducing factor and hypoxia-inducible factor-1α as well as a flow cytometry-based JC-1 mitochondrial membrane potential assay were performed.

RESULTS

Hemodynamic parameters were comparable between both groups. The cytochrome C release (HTK: 930.3 ± 804.4 pg/mg, HTK/CsA: 699.7 ± 394.0 pg/mg, p = 0.457) as well as PGC1α content (HTK: 66.7%, HTK/CsA: 33.3%, p = 0.284) was lower in the HTK/CsA group. Respiratory measurements revealed that the oxygen flux under basal respiration was higher in the HTK/CsA group (8.2 ± 1.3 pmol·O2·s-1·mg-1·ww) than in the HTK group (3.8 ± 1.4 pmol·O2·s-1·mg-1·ww, p = 0.045). There were no significant differences regarding histological surrogates of apoptosis and necrosis.

CONCLUSIONS

Supplementing cardioplegic solutions with CsA enhances the basal mitochondrial respiration thereby exerting a cardioprotective effect and diminishing IRI-induced damage. CsA seems to preserve mitochondrial function via non-ROS related pathways.

[Efficacy and short-term outcomes of myocardial protection using single-dose histidine-tryptophan-ketoglutarate cardioplegia during aortic root surgery with different duration of myocardial ischemia]

Objective: To explore the efficacy of myocardial protection with single-dose histidine-tryptophan-ketoglutarate (HTK) cardioplegia during aortic root operation, and the correlation between short-term clinical outcomes and duration of myocardial ischemia. Methods: The data of clinical cases undergoing myocardial protection with single-dose HTK cardioplegia during aortic root operation from January 2018 to December 2022 were retrospectively reviewed. Patients were divided into conventional HTK cardioplegia group (<3 h) and prolonged HTK cardioplegia group (≥3 h) according to duration of intraoperative myocardial ischemia. A 1∶1 propensity score matching was performed and the correlations between duration of myocardial ischemia and postoperative short-term outcomes (30-day mortality, readmission, mechanical circulation support and renal insufficiency) were analyzed. Results: A total of 282 patients were included in the final analysis, with 210 cases in the conventional HTK cardioplegia group and 72 cases inthe prolonged HTK cardioplegia group before matching. After matching, there were 64 cases (53 males and 11 females) in the conventional HTK cardioplegia group, with a mean age of (49.4±14.2) years. The prolonged HTK cardioplegia group had 64 cases (55 males and 9 females), with a mean age of (50.5±12.3) years. Higher sensitivity troponin [12 h: 10.1 (4.6, 18.7) μg/Lvs 4.1(2.2, 8.6) μg/L, P=0.002; 24 h: 7.7 (4.5, 19.0) μg/L vs 4.8 (2.2, 11.9) μg/L, P=0.025] and creatine kinase isoenzyme[12 h: 46.3 (28.1, 62.4) μg/L vs 20.7(14.1, 32.9) μg/L, P<0.001; 24 h: 26.3(13.4, 49.2) μg/L vs 14.5 (10.1, 33.5)μg/L, P=0.011] after surgery was detected in prolonged HTK cardioplegia group. Comparisons of other primary and secondary endpoint events showed no significant differences between the two groups (all P>0.05). Multivariate binary logistic regression showed that duration of myocardial ischemia had no significant effect on postoperative 30-day mortality (OR=1.255, 95%CI: 0.500-3.148, P=0.629), 30-day readmission (OR=0.378, 95%CI: 0.069-2.065, P=0.261) and mechanical circulation support (OR=0.991, 95%CI: 0.331-2.970, P=0.998). Conclusion: During aortic root surgery, single-dose HTK cardioplegia may provide satisfactory myocardial protection, and there was no significant correlation between duration of myocardial ischemia and short-term clinical outcomes.

Myocardial protection in cardiac surgery-hindsight from the 2020s

Myocardial protection and specifically cardioplegia have been extensively investigated in the beginnings of cardiac surgery. After cardiopulmonary bypass had become routine, more and more cardiac operations were possible, requiring reliable and reproducible protection for times of blood flow interruptions to the most energy-demanding organ of the body. The concepts of hypothermia and cardioplegia evolved as tools to extend cardiac ischaemia tolerance to a degree considered safe for the required operation. A plethora of different solutions and delivery techniques were developed achieving remarkable outcomes with cross-clamp times of up to 120 min and more. With the beginning of the new millennium, interest in myocardial protection research declined and, as a consequence, conventional cardiac surgery is currently performed using myocardial protection strategies that have not changed in decades. However, the context, in which cardiac surgery is currently performed, has changed during this time. Patients are now older and suffer from more comorbidities and, thus, other organs move more and more into the centre of risk assessment. Yet, systemic effects of cardioplegic solutions have never been in the focus of attention. They say hindsight is always 20-20. We therefore review the biochemical principles of ischaemia, reperfusion and cardioplegic extension of ischaemia tolerance and address the concepts of myocardial protection with 'hindsight from the 2020s'. In light of rising patient risk profiles, minimizing surgical trauma and improving perioperative morbidity management becomes key today. For cardioplegia, this means accounting not only for cardiac, but also for systemic effects of cardioplegic solutions.

Cold modified Del Nido cardioplegia in adults undergoing elective cardiac coronary surgery

INTRODUCTION

The cardioplegic solution of Kirklin (Kn) is frequently used in adult cardiosurgical patients. It requires reinfusion at short intervals, which causes further difficulty during surgery and the quality of myocardial protection is often called into question.

Comparison of Single-Dose Cardioplegia in Valvular Heart Surgery: Lactated Ringer's-Based del Nido vs. Histidine-Tryptophan-Ketoglutarate Cardioplegia Solution

INTRODUCTION

This study evaluated myocardial protection and clinical outcomes when using lactated Ringer's solution as the base solution for del Nido cardioplegia compared with histidine-tryptophan-ketoglutarate (HTK) solution in valvular surgery.

METHODS

From January 2017 to May 2018, 71 adult patients who underwent valvular surgery with del Nido cardioplegia (n=37) or HTK cardioplegia (n=34) were retrospectively analyzed.

RESULTS

Patients' characteristics were comparable between groups. Postoperative peak troponin T levels were similar. The del Nido group had a decreased incidence of ventricular fibrillation after aortic cross-clamp removal (13.51 vs. 55.88%; P<0.001), lower total volume of cardioplegia administered (1,000 [1,000, 1,250] vs. 1,800 [1,500, 2,000] mL; P<0.001), shorter hospital stay (6 [5, 8] vs. 7 [6, 10] days; P=0.03), and less postoperative red cell transfusion (34.29 vs. 61.11%; P=0.024). There is no difference in aortic cross-clamping time, postoperative change in left ventricular ejection fraction, intensive care unit stay, duration of inotropic support, new onset of atrial fibrillation, in-hospital mortality, complications, and three-year overall survival rate.

CONCLUSION

Lactated Ringer's-based del Nido cardioplegia can be safely used for valvular surgery with acceptable clinical outcomes compared to HTK cardioplegia.

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.

Assessing sex-based differences in postsurgical clinical outcomes after use of del Nido cardioplegia

OBJECTIVES

del Nido cardioplegia is used to pharmacologically arrest the heart during cardiac surgery and decrease reperfusion- and ischaemia-related myocardial injury. Studies have demonstrated the physiological differences between male and female hearts, potentially related to cardiac size or myocyte calcium handling; we aimed to assess for between-sex differences in clinical outcomes after receipt of del Nido cardioplegia.

METHODS

Patients who underwent coronary artery bypass or coronary artery bypass graft/valve surgery at our institution using del Nido cardioplegia (January 2014 to December 2019) were included (n = 2118). Clinical data were collected retrospectively. After the creation of a propensity-matched cohort (n = 1252), multivariable logistic regression was used to analyse binary postoperative outcomes, and a Gamma model was used for a continuous postoperative outcome. Our primary end-point was a composite end-point comprised of 30-day mortality and/or need for a post-bypass mechanical support device.

RESULTS

The final cohort included 459 females and 793 males (matched up to 1:2, all standardized mean differences <0.1). Multivariable logistic regression showed that biological sex was not associated with the composite primary end-point (odds ratio = 0.898, P = 0.779). A Gamma model indicated that there were no sex-related differences in vasoactive-inotropic scores reflecting vasopressor and inotrope usage at the time of patient operating room exit (exp[est] = 1.394, P = 0.189).

CONCLUSIONS

Our findings showed no significant between-sex differences in clinical outcomes after receiving del Nido cardioplegia, suggesting adequate myocardial protection as currently administered. Further research is warranted to elicit if there are sex-based differences between cardioplegic solutions.

IRB APPROVAL DATE (PROTOCOL NUMBER)

26 May 2021 (AAAR8359).

Neuroprotective Effects of a Cardioplegic Combination (Adenosine, Lidocaine, and Magnesium) in an Ischemic Stroke Model

Adenosine, lidocaine, and magnesium (ALM) are clinically available cardioplegic solutions. We examined the effects of low-dose ALM on ischemic stroke in cell and animal models. Cobalt chloride (CoCl₂)-treated SH-SY5Y cells were used as a surrogate model to mimic oxygen-glucose deprivation conditions. The cells were incubated with different dilutions of ALM authentic solution (1.0 mM adenosine, 2.0 mM lidocaine, and5 mM MgSO4 in Earle's balanced salt solution). At a concentration of 2.5%, ALM significantly reduced CoCl₂-induced cell loss. This protective effect persisted even when ALM was administered 1 h after the insult. We used transient middle cerebral artery occlusion to investigate the therapeutic effects of ALM in vivo. Rats were randomly assigned to two groups-the experimental (ALM) and control (saline) groups-and infusion was administered during the ischemia for 1 h. The infarction area was significantly reduced in the ALM group compared with the control group (5.0% ± 2.0% vs. 23.5% ± 5.5%, p = 0.013). Neurological deficits were reduced in the ALM group compared with the control group (modified Longa score: 0 [0-1] vs. 2 [1-2], p = 0.047). This neuroprotective effect was substantiated by a reduction in the levels of various neuronal injury markers in plasma. These results demonstrate the neuroprotective effects of ALM and may provide a new therapeutic strategy for ischemic stroke.

Impact of the Cardioplegia Interval on Myocardial Protection Using the Modified St. Thomas Solution in Minimally Invasive Mitral Valve Surgery: A Double-Center Study

It has been reported that a single-dose cardioplegia interval is useful, but the safe interval doses are not clear. We aimed to investigate the impact of the cardioplegia interval on myocardial protection using the modified St. Thomas solution. We included consecutive isolated minimally invasive mitral valvuloplasty procedures (n = 229) performed at a hospital and medical center from January 2014 to December 2020. We compared postoperative peak creatine kinase MB and creatine kinase levels and other indicators between the short (Group S, n = 135; maximum myocardial protection interval <60 minutes) and long (Group L, n = 94; maximum myocardial protection interval ≥60 minutes) interval groups. Propensity score matching was used to adjust for confounders between the two groups. After propensity score matching, Groups S and L contained 47 patients each. Groups S and L did not differ significantly in peak creatine kinase MB (45.8 ± 26.3 IU/L and 41.5 ± 27.9 IU/L, respectively; p = .441) and creatine kinase levels (1,133 ± 567 IU/L and 1,100 ± 916 IU/L, respectively; p = .837) after admission to the intensive care unit on the day of surgery based on propensity score matching. In multivariate analysis, a cardioplegia dosing interval ≥60 minutes was not significantly associated with the maximum creatine kinase MB level after admission to the intensive care unit on the day of surgery (p = .354; 95% confidence interval: -1.67 to 4.65). Using the antegrade modified St. Thomas solution, the long interval dose method is useful and safe in minimally invasive mitral valvuloplasty.

Comparison between Custodiol, del Nido and modified del Nido in the myocardial protection - Cardioplegia Trial: a study protocol for a randomised, double-blind clinical trial

INTRODUCTION

Myocardial protection is essential for successful cardiac surgery, and the search for an ideal cardioplegic solution has continued since its beginning. In this context, Custodiol, del Nido and modified del Nido are single-dose cardioplegic solutions with good safety profiles and great relevance in modern surgical practice. While these solutions have all been evaluated for their impact on patient outcomes independently, limited research exists comparing them directly. Thus, the present study aims to examine the effects of these cardioplegic solutions on myocardial protection and clinical outcomes in adult patients undergoing elective cardiac surgery. The assessment of the increase in myocardial injury biomarkers in patients submitted to all treatment methods may be considered a major strength of our study.

METHODS AND ANALYSIS

This is a clinical trial study protocol that will compare myocardial protection and clinical outcomes among three patient groups based on which cardioplegic solution was used. Patients will be randomised to receive del Nido (n=30), modified del Nido (n=30) or Custodiol (n=30). Myocardial injury biomarkers will be measured at the baseline and 2 hours, 12 hours and 24 hours after the cardiopulmonary bypass. Clinical outcomes will be assessed during the trans operative period and the intensive care unit stay, in addition to other haematological parameters.

ETHICS AND DISSEMINATION

This protocol and its related documents were approved by the Research Ethics Committee of the Hospital Nossa Senhora da Conceição, Brazil, registered under no. 4.029.545. The findings of this study will be published in a peer-reviewed journal in the related field.

TRIAL REGISTRATION NUMBER

RBR-7g5s66.

Efficacy of Whole-Blood Del Nido Cardioplegia Compared with Diluted Del Nido Cardioplegia in Coronary Artery Bypass Grafting: A Retrospective Monocentric Analysis of Pakistan

Background and Objectives: Cardioplegia is one of the most significant components used to protect the myocardium during cardiac surgery. There is a paucity of evidence regarding the utilization of whole-blood Del Nido cardioplegia (WB-DNC) on clinical outcomes in coronary artery bypass grafting (CABG). The purpose of this retrospective cross-sectional study is to compare the effectiveness of diluted (blood to crystalloid; 1:4) Del Nido cardioplegia (DNC) with WB-DNC in patients who underwent elective CABG in a tertiary care hospital in Lahore-Pakistan. Materials and Methods: This was a retrospective descriptive study conducted at the Department of Cardiovascular Surgery, King Edward Medical University, Lahore. The medical database of all consecutive patients admitted from January 2018 to March 2020 and who fulfilled the inclusion criteria were reviewed. Results: Out of 471 patients admitted during the study period, 450 underwent various elective cardiac surgeries. Out of 450, 321 patients (71.33%) were operated on for CABG. Only 234/321 (72.89%) CABG patients fulfilled our inclusion criteria; 120 (51.28%) patients received WB-DNC, while 114 (48.71%) patients were administered with DNC. The former group presented with better clinical outcomes compared with the latter in terms of lesser requirements of inotropic support, low degree of hemodilution, shorter in-hospital stay, improved renal function, and cost-effectiveness. Peak values of serum Troponin-T (Trop-T), creatine kinase-myocardial band (CK-MB) release, and activated clotting time (ACT) were also lower in the WB-DNC group compared with the DNC group. Conclusions: The WB-DNC conferred better myocardial protection, improved early clinical outcomes, and also proved to be economical for patients undergoing elective CABG compared with classical crystalloid cardioplegia solution.

Single- versus multidose cardioplegia in adult cardiac surgery patients: A meta-analysis

OBJECTIVE

To compare outcomes of single (intervention group: del Nido [DN], and histamine-tryptophan-ketoglutarate) versus multidose (control group) cardioplegia in the adult cardiac surgery patients.

METHODS

Medical search engines were interrogated to identify relevant randomized controlled trials and propensity-score matched cohorts. Meta-analysis was conducted for primary (in-hospital/30-day mortality) and secondary (ischemic and cardiopulmonary bypass [CPB] times, reperfusion fibrillation, peak of cardiac enzymes, myocardial infarction) endpoints. Subgroup analyses were conducted for study design and type of intervention, and meta-regression for primary outcome included type of surgery and left ventricular ejection fraction as moderators.

RESULTS

Ten randomized controlled trials and 13 propensity-score matched cohorts were included, reporting on 5516 patients. Estimates are expressed as (parameter value [OR, odds ratio; MD, mean difference; SMD, standardized mean difference]/unit of measure [95% confidence interval], P value). DN reduced ischemic time (MD, -7.18 minutes [-12.52 to -1.84], P < .01), CPB time (MD, -10.44 minutes [-18.99 to -1.88], P .01), reperfusion fibrillation (OR, 0.16 [0.05-0.54], P < .01), and cardiac enzymes (SMD -0.17 [-0.29, 0.05], P < .01) compared with multidose cardioplegia. None of these beneficial effects were reproduced by histamine-tryptophan-ketoglutarate, which instead increased CPB time (MD, 2.04 minutes [0.73-3.37], P < .01) and reperfusion fibrillation (OR, 1.80 [1.20-2.70], P < .01). There was no difference in mortality and myocardial infarction between single and multidose, independently of type of surgery or left ventricular ejection fraction.

CONCLUSIONS

DN decreases operative times, reperfusion fibrillation, and surge of cardiac enzymes compared with multidose cardioplegia.

Asanguinous Del Nido Cardioplegia for an Aortic Valve Replacement Patient with Cold Agglutinins

A patient with known cold agglutinins requiring an aortic valve replacement was referred for surgery. Asanguinous, Del Nido cardioplegia was used for myocardial protection. Warm induction followed by cold infusion prevented any agglutination and eliminated the need for subsequent cardioplegia doses. Following the cross-clamp period, the heart returned to normal sinus rhythm without need for defibrillation. Postoperative ejection fraction and systolic function were normal.

Comparative Study between the Use of Multidose Standard Cardioplegia and Long Acting Del Nido Cardioplegia during Intracardiac Repair for Tetralogy of Fallot in Pediatric Patients

Pediatric myocardium is unique from mature myocardium; thus, the use of adult cardioplegia for pediatric cardiac operations may provide suboptimal myocardial protection. It is found that children undergoing heart surgery show evidence of less myocardial damage when del Nido cardioplegia is used instead of a standard cardioplegic solution. Del Nido cardioplegia solution provides a depolarized hyperkalaemic arrest lasting up to 60 minutes, reduces spontaneous and inducible activity during arrest, and prevents hyper contraction during early reperfusion. In this single blind randomized trial, a total of 60 patients underwent intra cardiac repair for TOF in National Institute of Cardiovascular Diseases, Dhaka, Bangladesh from July 2014 to January 2016 fulfilling inclusion and exclusion criteria. They were randomly assigned in two groups- 30 patients in Del Nido group (Group A) and 30 patients in standard group (Group B). Comparison between groups was done by Chi square test and Student's test. All data were analyzed by SPSS 20.0 for windows. P value less than 0.05 was considered as significant. There was statistically significant difference among the patients in terms of mean total initial cardioplegia volume, mean number of additional dose, mean additional dose amount, mean cross clamp time, mean CPB time (331.67±188.07 vs. 458.67±226.62, p=0.022; 0.13±0.35 vs. 1.27±0.89, p=0.000; 23.33±60.76 vs. 336.83±259.6, p=0.000; 45.10±10.35 vs. 59.23±23.21, p=0.003; 89.30±15.73 vs. 111.10±29.23, p=0.001 respectively). Mean post operative serum troponin I level at arrival in ICU and after 24 hours between two groups were statistically significantly different (55.60±32.91 vs. 83.5±58.99; p=0.024 and 13.01±5.84 vs. 18.16±9.51; p=0.014 respectively). The mean ventilation duration, mean ICU stay were also statistically significant. This study showed that cardiac arrest with Del Nido cardioplegia during intra cardiac repair for TOF was associated with improved myocardial protection over standard cardioplegia in terms of reduced CPB and cross clamp times, lower total volume of cardioplegia.

Does the Type of Cardioplegia Solution Affect Intraoperative Glucose Levels? A Propensity-Matched Analysis

Myocardial protection during cardiac surgery is a multifaceted process that is structured to limit injury and preserve function. Evolving techniques use solutions with varying constituents that enter the systemic circulation and alter intrinsic systemic concentrations. This study compared two distinct cardioplegia solutions on affecting intraoperative glucose levels. Data were abstracted from a multi-institutional perfusion registry, including a total of 1,188 propensity-matched cases performed from January through October 2016, at 17 cardiac surgical centers across the United States in which both del Nido and 4:1 cardioplegia were used during the study period. Covariate data included insulin administration, crystalloid cardioplegia volume, diabetes history, glucose at operating room entry, and nine additional variables. Primary and secondary endpoints were the highest intraoperative glucose level and maximum glucose in excess of 180 mg/dL. Mixed-effects multivariable linear and logistic regression models were used to assess the primary and secondary endpoints, respectively, allowing for statistical control of center and surgeon effects. Greater median crystalloid cardioplegia volume was given in the del Nido group (n = 594) 1,040 mL [interquartile range (IQR) = {800, 1,339}] compared with the 4:1 group (n = 594) 466 mL [IQR = {360, 660}] in the 4:1 group (p < .001) despite these groups being statistically indistinguishable in terms of bypass and cross-clamp times as well as seven other patient covariates. More patients required intraoperative insulin drip in the 4:1 group compared with del Nido (65.7% vs. 56.2%, p < .001). Multivariable linear mixed-effects analysis yielded an estimated maximum intraoperative glucose for the del Nido group of 177.8 mg/dL compared with that of the 4:1 group, 183.5 mg/dL-a statistically significant reduction of 5.7 mg/dL (p = .03). Multivariable logistic mixed-effects analysis showed a statistically nonsignificant reduction in the likelihood of crossing the 180 mg/dL threshold for del Nido compared with 4:1 (odds ratio [OR] = .79, p = .214). After controlling for known confounding variables, intraoperative maximum glucose levels for the del Nido group were 5.7 mg/dL lower than that of the 4:1 group; there was limited evidence suggesting a difference between methods in the likelihood of exceeding the threshold of 180 mg/dL intraoperatively. Further research is warranted to examine the differential effects of cardioplegia solution on intraoperative glucose levels.

Does the Type of Cardioplegic Technique Influence Hemodilution and Transfusion Requirements in Adult Patients Undergoing Cardiac Surgery?

During cardiac surgery, myocardial protection is performed using diverse cardioplegic (CP) solutions with and without the presence of blood. New CP formulations extend ischemic intervals but use high-volume, crystalloid-based solutions. The present study evaluated four commonly used CP solutions and their effect on hemodilution during cardiopulmonary bypass (CPB). Records from 16,670 adult patients undergoing cardiac surgery with CPB between February 2016 and January 2017 were reviewed. Patients were classified into one of four groups according to CP type: 4-1 blood to crystalloid (4:1), microplegia (MP), del Nido (DN) and histidine-tryptophan-ketoglutarate (HTK). Covariate-adjusted estimates of group differences were calculated using multivariable logistic and linear mixed effects regression models. The primary end point was intraoperative transfusion of allogeneic red blood cells (RBCs), with a secondary end point of intraoperative hematocrit change. Among all patients, 8,350 (50.1%) received 4:1, 4,606 (27.6%) MP, 3,344 (20.1%) DN, and 370 (2.2%) HTK. Both 4:1 and MP were more likely to be used in patients undergoing coronary revascularization surgery, whereas DN and HTK were seen more often in patients undergoing valve surgery (p < .001). The highest volume of crystalloid CP solution was seen in the HTK group, 2,000 [1,754, 2200], whereas MP had the lowest, 50 [32, 67], p < .001. Ultrafiltration usage was as follows: HTK-84.9%. DN-83.7%, MP-40.1%, and 4:1-34.0%, p < .001. There were no statistically significant differences on the primary outcome risk of intraoperative RBC transfusion. However, statistically significant differences among all but one of the pair-wise comparisons of CP methods on hematocrit change (p < .05 or smaller), with MP having the lowest predicted drift (-7.8%) and HTK having the highest (-9.4%). During cardiac surgery, the administration of different CP formulations results in varying intraoperative hematocrit changes related to the volume of crystalloid solution administered.

A protocol for the 0.9% saline versus Plasma-Lyte 148 for intensive care fluid therapy (SPLIT) study

BACKGROUND

0.9% saline is the most commonly used intravenous (IV) fluid in the world. However, recent data raise the possibility that, compared with buffered crystalloid fluids such as Plasma-Lyte 148, the administration of 0.9% saline to intensive care unit patients might increase their risk of acute kidney injury (AKI).

OBJECTIVE

To describe the protocol for the 0.9% Saline v Plasma-Lyte 148 for ICU Fluid Therapy (SPLIT) study.

METHODS

This is a multicentre, cluster-randomised, double crossover feasibility study to be conducted in four New Zealand tertiary ICUs over a 28-week period and will enroll about 2300 participants. All ICU patients who need crystalloid IV fluid therapy (except those with established renal failure needing dialysis and those admitted to the ICU for palliative care) will be enrolled. Participating ICUs will be randomly assigned to 0.9% saline or Plasma-Lyte 148 as the routine crystalloid IV fluid, in a blinded fashion, in four alternating 7-week blocks.

MAIN OUTCOME MEASURES

The primary outcome will be the proportion of patients who develop AKI in the ICU. Secondary outcomes will include the difference between the most recent serum creatinine level measured before study enrollment and the peak serum creatinine level in the ICU; use of renal replacement therapy; and ICU and in hospital mortality. All analyses will be conducted on an intention-to-treat basis.

RESULTS AND CONCLUSION

The SPLIT study started on 1 April 2014 and will provide preliminary data on the comparative effectiveness of using 0.9% saline v Plasma- Lyte 148 as the routine IV fluid therapy in ICU patients.

Out-of-hospital administration of intravenous glucose-insulin-potassium in patients with suspected acute coronary syndromes: the IMMEDIATE randomized controlled trial

CONTEXT

Laboratory studies suggest that in the setting of cardiac ischemia, immediate intravenous glucose-insulin-potassium (GIK) reduces ischemia-related arrhythmias and myocardial injury. Clinical trials have not consistently shown these benefits, possibly due to delayed administration.

OBJECTIVE

To test out-of hospital emergency medical service (EMS) administration of GIK in the first hours of suspected acute coronary syndromes (ACS).

DESIGN, SETTING, AND PARTICIPANTS

Randomized, placebo-controlled, double-blind effectiveness trial in 13 US cities (36 EMS agencies), from December 2006 through July 31, 2011, in which paramedics, aided by electrocardiograph (ECG)-based decision support, randomized 911 (871 enrolled) patients (mean age, 63.6 years; 71.0% men) with high probability of ACS.

INTERVENTION

Intravenous GIK solution (n = 411) or identical-appearing 5% glucose placebo (n = 460) administered by paramedics in the out-of-hospital setting and continued for 12 hours.

MAIN OUTCOME MEASURES

The prespecified primary end point was progression of ACS to myocardial infarction (MI) within 24 hours, as assessed by biomarkers and ECG evidence. Prespecified secondary end points included survival at 30 days and a composite of prehospital or in-hospital cardiac arrest or in-hospital mortality, analyzed by intent-to-treat and by presentation with ST-segment elevation.

RESULTS

There was no significant difference in the rate of progression to MI among patients who received GIK (n = 200; 48.7%) vs those who received placebo (n = 242; 52.6%) (odds ratio [OR], 0.88; 95% CI, 0.66-1.13; P = .28). Thirty-day mortality was 4.4% with GIK vs 6.1% with placebo (hazard ratio [HR], 0.72; 95% CI, 0.40-1.29; P = .27). The composite of cardiac arrest or in-hospital mortality occurred in 4.4% with GIK vs 8.7% with placebo (OR, 0.48; 95% CI, 0.27-0.85; P = .01). Among patients with ST-segment elevation (163 with GIK and 194 with placebo), progression to MI was 85.3% with GIK vs 88.7% with placebo (OR, 0.74; 95% CI, 0.40-1.38; P = .34); 30-day mortality was 4.9% with GIK vs 7.7% with placebo (HR, 0.63; 95% CI, 0.27-1.49; P = .29). The composite outcome of cardiac arrest or in-hospital mortality was 6.1% with GIK vs 14.4% with placebo (OR, 0.39; 95% CI, 0.18-0.82; P = .01). Serious adverse events occurred in 6.8% (n = 28) with GIK vs 8.9% (n = 41) with placebo (P = .26).

CONCLUSIONS

Among patients with suspected ACS, out-of-hospital administration of intravenous GIK, compared with glucose placebo, did not reduce progression to MI. Compared with placebo, GIK administration was not associated with improvement in 30-day survival but was associated with lower rates of the composite outcome of cardiac arrest or in-hospital mortality.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00091507.

[Myocardial protection of cardioplegic solution with Salvia miltiorrhizae in extracorporeal circulation of coronary artery bypass graft]

OBJECTIVE

To observe the myocardial protection of cardioplegic solution with Salvia miltiorrhizae (SM) in extracorporeal circulation of coronary artery bypass graft (CABG) and to investigate the mechanisms of SM.

METHODS

30 patients who received CABG under extracorporeal circulation were randomly assigned to two groups, the observation group (15 cases) and the control group (15 cases). Patients in the observation group received the cardioplegic solution with SM and those in the control group received the cardioplegic solution without SM. The indices such as serum SOD activities, MDA contents, LDH, CK-MB, cTnl levels, the rate of heart reskip, activated coagulation time (ACT), the time of assisted respiration, and the days of in-hospital after operation were observed in the two groups pre-operation, post-operation, 6 h and 24 h post-operation, respectively.

RESULTS

When compared with the control group, MDA contents, LDH, CK-MB, cTnl levels were lower, SOD activities (all P<0.05) and heart re-skip rate (P>0.05) higher in the observation group. There was no statistical significance in the time of assisted respiration, the days of in-hospital, or ACT in the two groups (P>0.05).

CONCLUSIONS

The application of cardioplegic solution with SM in extracorporeal circulation of CABG showed obvious myocardial protection. It had better effects than the cardioplegic solution with no SM.

Metabolic monitoring of postischemic myocardium during intermittent warm-blood cardioplegic administration

In 12 patients undergoing elective myocardial revascularization with intermittent administration of warm-blood cardioplegic solution for myocardial protection, we analyzed metabolic changes by assay of global ischemia indicators (pH, lactate, glucose, and potassium), which we measured in the coronary sinus and arterial blood during the ischemic and postischemic periods. A typical cumulative ischemic pattern with progressively decreasing pH values and progressively increasing lactate values could not be observed in all patients. It was not the degree of lactate washout, but the lactate concentration at the end of each reperfusion, that correlated significantly with global metabolic recovery time, which suggests the importance of effective reperfusion.

[Effect of perfusion volume of the Custodiol solution on the efficiency of cardioplegia in experiment]

The purpose of the present study was to compare the efficiency of small and standard volumes (1.5-20 and 7-10 ml/g of the myocardium, respectively) of Custodiol solution in myocardial ischemia lasting 2 and 4 hours. Experiments were carried out on 24 mongrel dogs weighing 22-36 kg under extracorporeal circulation (EC) with bicaval cannulation under moderate general hypothermia and balanced general intravenous anesthesia. According to the solution volume and cardioplegia (CP) duration, all the animals were divided into 4 groups: 1) 2-hour CP (standard volume); 2) 2-hour CP (small volume); 3) 4-hour CP (standard volume); 4) 4-hour CP (small volume); of them Groups 1 and 3 served as a control. Antegrade CP was accomplished by the conventional procedure. In Groups 1 and 3, the volume of Custodiol solution was 1000-2000 ml; in Groups 2 and 4, that was 300-600 ml depending on myocardial mass. In Groups 1 and 3, the mean duration of myocardial perfusion was 9.8+/-2.8 and 8.4+/-1.4 min, respectively; and in Groups 2 and 4, that was 4.2+/-0.7 and 4.5+/-1.4 min. Groups 3 and 4 animals received additional myocardial perfusion with Custodiol solution in a volume of 400-500 and 200-250 ml, respectively. The efficiency of myocardial protection was evaluated from the course of a reperfusion period (RP) and from central hemodynamic changes, the concentrations of glucose, lactate, malonic dialdehyde, medium-weight molecules, and blood gas and electrolyte composition of the coronary sinus. The studies were performed in stages: outcome, launch of blood flow (5-10 in); RP (30 min); complete loading (30 min); disconnection from an extracorporeal circulation apparatus. The experiment has indicated that the use of Custodiol solution in the standard volumes ensures an effective cardioplegic protection within 4 hours. Reductions in the volume and time of perfusion to the values characteristic of extracellular-type solutions cause a lower efficiency of this protection. Moreover, myocardial damage progresses as the duration of CP increases. The used Custodiol solution dose of 1.5-2.0 ml/g of the myocardium is apparent to be insufficient to set an ionic balance between cardioplegic solution and intracellular fluid, which reduces the duration of CP effect and the efficiency of myocardial protection. It may be assumed that lower perfusion volume lowers the efficiency of the buffer system of the solution and the metabolic effects of substrates. The authors consider that the decreased volume and time of perfusion of intracellular Custodial solution are unjustified and may result in the development of complications associated with inadequate cardioplegic myocardial protection.

[Effect of high dose glucose-insulin-potassium infusion in patients with acute ST-segment elevation myocardial infarction: analysis of 7510 patients in China as part of CREATE-ECLA study]

OBJECTIVE

To investigate the effect of high-dose glucose-insulin-potassium (GIK) infusion on the outcomes of ST-elevation myocardial infarction (STEMI) in China.

METHODS

As part of the international multicentre CREATE-ECLA study, 7510 patients with STEMI, aged (62 +/- 12), presenting their symptoms within 12 hours of onset who were hospitalized in 274 centers throughout China from July 2001 through July 2004 were randomized to receive GIK intravenous infusion for 24 hours plus routine treatment (3739) or control group (n=3771) receiving routine treatment alone. The patients were flowed up in the out-patient department 30 days after the randomization to assess the rates of mortality, cardiac arrest, cardiogenic shock and re-infarction.

RESULTS

The median time from symptom onset to randomization was 5.8 hours. The mortality of the control group was 10.4%, not significantly different from that of the GIK group (11.2%, hazard ratio = 1.05, 95% CI: 0.916-1.207, P = 0.476). There rates of cardiac arrest, cardiogenic shock, and re-infarction of the GIK group were 0.8%, 6.8%, and 2.0% respectively, all not significantly different from those of the control group (1.0%, 6.4%, and 1.9% respectively, all P > 0.05). At the Day 7 the heart failure rate of the GIK group was 19.7%, not significantly different from that of the control group (18.3%, P = 0.102). The symptomatic hypotension rate of the GIK group was 3.7%, significantly higher than that of the control group (1.2%, P < 0.01). The phlebitis rate of the GIK group was 2.2%, significantly higher than that f the control group (0.1%, P < 0.01). The net increased fluid volume of the control group wasl3 584 ml. more than that of the GIK group (1036 ml).

CONCLUSIONS

High dose GIK infusion has neutral effect on mortality, cardiac arrest or cardiogenic shock in patients with acute STEMI in China.

Glucose-insulin-potassium therapy in patients with ST-segment elevation myocardial infarction

CONTEXT

The clinical benefit of glucose-insulin-potassium (GIK) infusion in patients with ST-segment elevation myocardial infarction (STEMI) is unclear. While some smaller trials suggest benefit, in the CREATE-ECLA trial, GIK infusion had no effect on 30-day mortality in 20,201 patients.

OBJECTIVES

To determine the association between GIK infusion therapy and 30-day and 6-month outcomes in patients with STEMI.

DESIGN, SETTING, AND PARTICIPANTS

Primary analysis of the OASIS-6 GIK randomized controlled trial of 2748 patients with acute STEMI; prespecified analyses of the combined trial data from the OASIS-6 GIK and CREATE-ECLA GIK trial populations of 22,943 patients with acute STEMI; subgroup analysis on the timing of initiation of GIK infusion therapy and outcomes; and post hoc analyses exploring whether GIK infusion may cause early harm by increasing glucose and potassium levels and net fluid gain.

INTERVENTION

High-dose GIK solution consisting of 25% glucose, 50 U/L of regular insulin, and 80 mEq/L of potassium infused at 1.5 mL/kg per hour for 24 hours.

MAIN OUTCOME MEASURES

Mortality rates at 30 days and 6 months in the OASIS-6 GIK trial and rates of death, heart failure, and the composite of death or heart failure at 3 and 30 days in the combined OASIS-6 GIK and CREATE-ECLA GIK trial populations.

RESULTS

At 6 months, 148 (10.8%) GIK infusion patients and 143 (10.4%) control patients died in the OASIS-6 trial (hazard ratio [HR], 1.04; 95% CI, 0.83-1.31; P = .72); 153 (11.1%) GIK patients and 185 (13.5%) control patients had heart failure (HR, 0.83; 95% CI, 0.67-1.02; P = .08); and 240 (17.5%) GIK patients and 264 (19.2%) control patients had a composite of death or heart failure (HR, 0.91; 95% CI, 0.76-1.08; P = .27). In the prespecified analyses of the combined trial data, there were 712 deaths (6.2%) in the GIK group and 632 deaths (5.5%) in the control group at 3 days (HR, 1.13; 95% CI, 1.02-1.26; P = .03). This difference disappeared by 30 days, with 1108 deaths (9.7%) in the GIK group and 1068 (9.3%) in the control group (HR, 1.04; 95% CI, 0.96-1.13; P = .33). GIK therapy increased levels of glucose, potassium, and net fluid gain postinfusion, all 3 of which predicted death after adjusting for multiple confounders. Adjusting for glucose, potassium, and net fluid gain eliminated the apparent increase in mortality at 3 days observed with GIK infusion, suggesting a direct association with these factors. Administration of GIK infusion within 4 hours of symptom onset yielded no benefit compared with later initiation.

CONCLUSIONS

Infusion of GIK provided no benefit and may cause early harm following STEMI. Avoidance of infusion-related hyperglycemia, hyperkalemia, and net fluid gain may be advisable in future studies of metabolic modulation in patients with STEMI.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00064428.

Does Intermittent Aortic Cross Clamping Decrease the Incidence of Atrial Fibrillation after Coronary Bypass Surgery?

Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG). AF is a vexing problem that causes morbidity, prolongs hospital stay, and increases costs. Numerous factors have been suggested to play a role in the development of AF. The aim of this study was to evaluate the effect of intermittent aortic cross clamping (IACC) compared with hypothermic cardioplegic solution (HCS) in the development of postoperative AF. We evaluated data obtained from 345 patients undergoing CABG with HCS (HCS group, n = 212) and IACC (IACC group, n = 173) between April 2004 and August 2005. Diabetes mellitus was observed more often in the HCS group (P < .05), otherwise both groups had similar preoperative characteristics including sex, age, the number of distal anastomoses, left ventricle ejection fraction, history of myocardial infarction, and use of beta-blocker medication. The only statistically significant difference between the groups was higher postoperative Ca-antagonist use in the HCS group. Rates of postoperative AF, however, were significantly lower in the IACC group (21.52%) than that in the HCS group (11.05%; P < .01). Postoperative Ca-antagonist use in the HCS group and smoking in the IACC group were independent predictors of AF after CABG. The incidence of postoperative AF after CABG with IACC was reduced compared with HCS. IACC with ventricular fibrillation may exert a counteractive effect against AF.

Nitric oxide homeostasis as a target for drug additives to cardioplegia

The vascular endothelium of the coronary arteries has been identified as the important organ that locally regulates coronary perfusion and cardiac function by paracrine secretion of nitric oxide (NO) and vasoactive peptides. NO is constitutively produced in endothelial cells by endothelial nitric oxide synthase (eNOS). NO derived from this enzyme exerts important biological functions including vasodilatation, scavenging of superoxide and inhibition of platelet aggregation. Routine cardiac surgery or cardiologic interventions lead to a serious temporary or persistent disturbance in NO homeostasis. The clinical consequences are "endothelial dysfunction", leading to "myocardial dysfunction": no- or low-reflow phenomenon and temporary reduction of myocardial pump function. Uncoupling of eNOS (one electron transfer to molecular oxygen, the second substrate of eNOS) during ischemia-reperfusion due to diminished availability of L-arginine and/or tetrahydrobiopterin is even discussed as one major source of superoxide formation. Therefore maintenance of normal NO homeostasis seems to be an important factor protecting from ischemia/reperfusion (I/R) injury. Both, the clinical situations of cardioplegic arrest as well as hypothermic cardioplegic storage are followed by reperfusion. However, the presently used cardioplegic solutions to arrest and/or store the heart, thereby reducing myocardial oxygen consumption and metabolism, are designed to preserve myocytes mainly and not endothelial cells. This review will focus on possible drug additives to cardioplegia, which may help to maintain normal NO homeostasis after I/R.

Adenosine instead of supranormal potassium in cardioplegic solution improves cardioprotection

OBJECTIVE

To determine whether adenosine instead of supranormal potassium in cold crystalloid cardioplegia gives satisfactory cardiac arrest and improved cardioprotection. Cold crystalloid cardioplegia with adenosine, procaine and magnesium (A) was compared with standard cold crystalloid hyperkalemic cardioplegia (K).

METHODS

Sixteen pigs were randomized to receive either cold K (n=8) or A (n=8), where hyperkalemia was substituted with 1.2 mM adenosine. The cold (6 degrees C) cardioplegia was given intermittently and antegradely, with an aortic cross-clamp time of 1 h. Hemodynamic data was continuously measured and pressure-volume conductance catheters were used to determine global left ventricular systolic and diastolic function. Coronary flow and O2 content differences allowed determination of left ventricular energetics. Blood samples, and left ventricular microdialysis were used to measure parameters of ischemia. Measurements were done at 1 and 2 h after cross-clamp release.

RESULTS

Mean arterial pressure was reduced with 55 mmHg (standard deviation, SD: 19) in the K group versus 30 mmHg (SD: 14) in the A group 2 h after cross-clamp release (p=0.030). Left ventricular contractility expressed as slope of the preload recruitable stroke work index (Mw) was reduced to 53% (SD: 14) in the K group versus 78% (SD: 23) in the A group 2h after cross-clamp release (p=0.046). Reduction of maximum of first derivate of pressure with respect to time (dP/dtmax) was 804 mmHg/s (SD: 189) in the K group versus 538 mmHg/s (SD: 184) in the A group (p=0.033). The slope of the myocardial oxygen consumption-pressure volume area was at 2 h reperfusion increased from 1.37 (SD: 0.64) to 2.86 (SD: 1.27) in the K group, whereas no shift was detected in the A group (p=0.019). Cardiac troponin T measured in the coronary sinus 1 h after cross-clamp release was 1.25 microg/l (SD: 0.64) in the K group versus 0.73 microg/l (SD: 0.31) in the A group (p=0.046).

CONCLUSION

Adenosine instead of supranormal potassium in cold crystalloid cardioplegia gives satisfactory cardiac arrest, improves post cardioplegic left ventricular systolic function and efficiency, and attenuates myocardial cell damage.

Lidocaine-magnesium blood cardioplegia was equivalent to potassium blood cardioplegia in left ventricular function of canine heart

This study evaluated the effects of lidocaine-magnesium blood cardioplegia on left ventricular function compared with potassium blood cardioplegia. Crystalloid cardioplegia which contains lidocaine has been reported but blood cardioplegia is rare. Thirteen dogs received 60 min of global ischemia under hypothermic cardioplumonary bypass (30 degrees C). Potassium blood cardioplegia was administered every 20 min in group A (n=6), and lidocaine-magnesium blood cardioplegia in group B (n=7). We compared the ratio of Emax obtained during IVC occlusion at pre- and post-global ischemia (%Emax) and LVSW (%LVSV). Cardiac function was evaluated prior to CPB and 60 min after reperfusion. There was no difference in time required for cardiac arrest between the two groups (group A: 78+/-3 s, group B: 89+/-9 s). Percentage maximal elastance was significantly better in group B (group A: 63+/-3%, group B: 76+/-4%, P<0.05). Percentage tissue water content of the myocardium after CPB was significantly lower in group B (group A: 82.3+/-4%, group B: 75.5+/-2%, P<0.05). Lidocaine-magnesium blood cardioplegia was equivalent to potassium blood cardioplegia in systolic left ventricular function and reduced myocardial edema in canine heart.

Benefits of terminal noncardioplegic warm blood retrograde perfusion after terminal warm blood cardioplegia perfusion prior to aortic unclamping in open heart surgery

AIM

The benefits of terminal noncardioplegic warm blood retrograde perfusion (TNWB) and terminal warm blood cardioplegia perfusion (TWBC) after intermittent cold blood cardioplegia perfusion during aortic clamping were studied.

METHODS

The clinical results of consecutive 128 patients who underwent on pump coronary artery bypass grafting (CABG) or valvular surgery were studied retrospectively. The aortic cross-clamp was removed (1) after five-minute TWBC and sequential three-minute TNWB in 59 patients (TNWB group), (2) immediately after five-minute TWBC in 29 patients (TWBC group), or (3) with neither TWBC or TNWB in 36 patients (control group).

RESULTS

The incidence of spontaneous heart beat recovery was best in TNWB group, second in TNBC, and worst in control group (TNWB: 86, TWBC: 42, CONTROL: 14%). The duration from aortic unclamping to heart beat recovery was shorter in TNWB group than TWBC group (TNWB: 2.1, TWB: 4.3 min). Cardiopulmonary bypass duration after aortic unclamping was shortest in TNWB group, second in TWBC group, and longest in control group (TNWB: 21.3, TWB: 27.5, CONTROL: 46.9 min). The postoperative CPK-MB was lowest in TNWB group (TNWB: 65.3, TWB: 87.7, CONTROL: 91.9U/L). Duration of intubation in TNWB group or TWBC group was shorter than control.

CONCLUSIONS

Combination of the terminal noncardioplegic warm blood perfusion and terminal warm blood cardioplegic perfusion contributes to increase the incidence of spontaneous heart beat recovery, shortens cardiopulmonary bypass duration following aortic unclamping, and lowers postoperative CPK-MB.