Reperfusion ventricular fibrillation during coronary artery bypass operations and its association with postoperative enzyme release

del Nido and Histidine-Tryptophan-Ketoglutarate cardioplegia in minimally invasive mitral valve surgery: A propensity-Match study

INTRODUCTION

In the last decade, del Nido cardioplegia has been embedded in adult cardiac surgery involving CABG and aortic valve surgical procedures. We reviewed our early experience with del Nido cardioplegia in the setting of minimally invasive mitral valve surgery.

METHODS

Data on 120 consecutive patients operated between 03/2021 and 06/2022 were retrieved from our internal database (infective endocarditis and urgent operations were excluded). Patients were divided into two groups according to the use of Histidine-Tryptophan-Ketoglutarate or del Nido cardioplegia. A propensity match analysis was performed using thirteen preoperative and intraoperative variables. Several intraoperative data and early postoperative outcomes were investigated, including cardiac enzymes (Troponin I HS and CK-MB) measured upon arrival in the Intensive Care Unit (ICU), after 12 hours and everyday thereafter.

RESULTS

There was no difference in preoperative characteristics and surgical techniques between both unmatched and matched Histidine-Tryptophan-Ketoglutarate and del Nido populations. Patients in the del Nido group received a lower volume of cardioplegia (p < 0.001) and ultrafiltration during CPB (p < 0.001). Histidine-Tryptophan-Ketoglutarate was associated with a lower rate of post cross-clamp spontaneous defibrillation (p < 0.001) and showed a lower level of blood sodium after CPB (p < 0.001). The release of cardiac enzymes was similar between the two groups (p = 0.72). There was no difference in terms of postoperative morbidity and 30 day mortality.

CONCLUSIONS

del Nido cardioplegia in the setting of minimally invasive mitral valve surgery seemed safe with acceptable myocardial protection and excellent early outcomes.

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.

The Effect of Prophylactic Intravenous Amiodarone Administration on Reperfusion Ventricular Fibrillation in Patients With Left Ventricular Hypertrophy Undergoing Cardiopulmonary Bypass Surgery: Protocol for a Randomized Double-Blind Clinical Trial

BACKGROUND

Ventricular fibrillation (VF) is a common arrhythmia that occurs after the release of aortic cross-clamp (ACC) in patients undergoing cardiopulmonary bypass (CPB) surgery. Repeated defibrillation and long duration of VF could increase myocardial injuries. In patients with left ventricular hypertrophy (LVH), VF is easier to occur and more difficult to be terminated. Amiodarone, known as class III antiarrhythmic agent, has the prominent properties of converting VF and restoring the sinus rhythm. Before ACC release, administration of amiodarone has been confirmed useful to reduce occurrence of VF. However, few studies are focused on the effect of amiodarone before ACC release on reducing VF in patients with LVH.

OBJECTIVE

This study aimed at determining the efficacy of prophylactic intravenous amiodarone administration on reperfusion VF after release of ACC in patients with LVH undergoing CPB surgery.

METHODS

This will be a prospective, randomized, double-blind, placebo-controlled trial. The trial will enroll 54 patients with LVH aged 18-75 years who will undergo CPB surgery. All eligible participants will be randomly allocated to either the amiodarone or placebo group by using the block randomization in a 1:1 ratio. The primary end point will be the incidence rate of VF 30 minutes after ACC release and be assessed using the Fisher exact test. All data will be analyzed in accordance with the intention-to-treat principle.

RESULTS

The study began in August 2022, and the data collection will take place for the next 2 academic years. As of this writing, 21 participants have already been recruited for the study.

CONCLUSIONS

With this trial, we are hoping to demonstrate that prophylactic infusion of amiodarone before ACC release could reduce the occurrence of reperfusion VF in patients with LVH.

TRIAL REGISTRATION

ClinicalTrials.gov ChiCTR2000035057; https://www.chictr.org.cn/showprojen.aspx?proj=57145.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/40115.

Preoperative Risk Prediction Score for and In-Hospital Clinical Outcomes of Reperfusion Ventricular Fibrillation After Release of Aortic Cross-Clamps: A Retrospective Study

Reperfusion ventricular fibrillation (VF) is a common arrhythmia after cardiac surgery. Predictors of reperfusion VF and its relationships with the adverse prognosis are still unclear. This study aimed to identify a risk score model to predict reperfusion VF and its effect on in-hospital outcomes. The authors enrolled 1,024 consecutive patients undergoing cardiac surgery, and a total of 823 patients were included in the study. A novel risk score model was developed following logistic regression analysis of the predictors of reperfusion VF. The receiver operating characteristic curve was used to validate this model, and the effect of VF on prognosis was later identified in multivariate or Kaplan-Meier analyses. Risk factors for reperfusion VF occurrence included weight >55 kg, preoperative left ventricular ejection fraction <50%, prior stroke, hypertension, aortic valve replacement, HTK solution, and the use of ≥3 grafts in coronary artery bypass grafting. A novel risk score model was developed using the abovementioned variables, and points were assigned to each risk factor according to its odds ratio. A high score (>6) predicted greater than 65% of patients with VF occurrence. Reperfusion VF increased the risk of in-hospital cardiovascular death (p = 0.03) and renal replacement therapy postoperatively (p = 0.022). More attention should be given to reperfusion VF due to an adverse postoperative prognosis, and the developed risk score model may predict this risk.

The del Nido versus cold blood cardioplegia in aortic valve replacement: A randomized trial

OBJECTIVES

To compare the cardioprotective efficacy of a solution that requires only a single infusion at the start of the ischemic duration versus a solution that requires multiple infusions.

METHODS

Aortic valve replacement was performed for 150 patients, who were randomized into the del Nido (DN) cardioplegia group or the cold blood (CB) cardioplegia group. The DN cardioplegia was delivered every 90 minutes and the CB cardioplegia was delivered every 20 to 30 minutes, or whenever cardiac activity was observed. The primary endpoints were electrical cardiac activity during crossclamp, ventricular fibrillation during reperfusion, and postoperative troponin and creatine kinase (CK-MB isoenzyme) at 24 and 48 hours.

RESULTS

Electrical activity during crossclamp occurred in 29 (39.7%) patients in the DN group versus 34 (45.3%) patients in the CB group (adjusted P = 1.0). The number of procedures with ventricular fibrillation after removing the crossclamp was 41 (54.7%) in the CB group versus 17 (22.7%) in the DN group (adjusted P = .001; relative risk, 2.41). Troponin values appeared to be lower in the DN group (median, 223.10; interquartile range, 168.35-364.77 pg/mL vs 285.5; 196.20-419.45 pg/mL at 24 hours and 159.60; 125.42-217.20 pg/mL vs 201.60; 160.62-268.45 pg/mL at 48 hours) and CK-MB (median, 14.94; interquartile range, 12.16-20.39 ng/mL vs 17.43; 13.66-22.43 ng/mL at 24 hours and 6.19; 4.41-7.63 ng/mL vs 7.38; 4.74-10.20 ng/mL at 48 hours), but no significance was found.

CONCLUSIONS

The del Nido cardioplegia protocol is an acceptable alternative for cold blood cardioplegia in patients undergoing aortic valve replacement.

Postcardioplegia ventricular fibrillation: no impact on subsequent survival

OBJECTIVES

At aortic declamping after cardioplegic cardiac arrest, the initial rhythm can be broadly classified as ventricular fibrillation (VF) or non-VF. VF can be treated with potassium-induced conversion and direct-current countershock is only applied if potassium treatment fails. We aimed to investigate whether there are any differences between these groups of patients in regard to outcomes.

DESIGN

From January 1999 through December 2010, 12,113 patients underwent various types of cardiac surgery. Data from every patient were consecutively registered. Survival was established through the Norwegian National Registry. Cox multivariable modeling with adjustment for clinical, biochemical, and medication baseline data was used for survival analysis.

RESULTS

The mean follow-up time was 7.4 years and total patient-years were 89,268. The percentage of all-cause deaths was 24.9. Adjusted survival for patients with no postcardioplegia VF (n = 9723) and patients with successful potassium-induced conversion (n = 1877) was completely identical. Four hundred patients with electrical conversion after failed potassium treatment had a nonsignificant trend toward an increased mortality (hazard ratio, 95% confidence interval: 1.19 (0.99-1.4); p = 0.07).

CONCLUSIONS

This is the first study reporting the association between postcardioplegia VF, its treatment with potassium and outcome. No impact was found on outcome as judged by all-cause mortality.

Lidocaine for prevention of reperfusion ventricular fibrillation after release of aortic cross-clamping

OBJECTIVE

To determine the efficacy of a bolus of lidocaine administered by way of the pump before releasing the aortic cross-clamp (ACC) in preventing the occurrence of reperfusion ventricular fibrillation.

DESIGN

Prospective, randomized study.

SETTING

University hospital.

PARTICIPANTS

Patients undergoing coronary artery bypass graft surgery (n = 34).

INTERVENTIONS

Seventeen patients received 100 mg of lidocaine by way of the pump 2 minutes before releasing the ACC, and a control group of 17 patients received 5 mL of normal saline.

MEASUREMENTS AND MAIN RESULTS

In the control group, the incidence of reperfusion ventricular fibrillation was 70%, which was significantly decreased to 11% in the lidocaine group. A higher cardiac output after weaning from cardiopulmonary bypass was observed in the lidocaine group; this may be attributed to the lower incidence of reperfusion ventricular fibrillation and consequently the lower need for defibrillation by electric countershocks.

CONCLUSIONS

The results suggest that a bolus of 100 mg of lidocaine administered 2 minutes before release of the ACC can safely decrease the incidence of reperfusion ventricular fibrillation and is associated with better hemodynamics after weaning from cardiopulmonary bypass.

Reperfusion ventricular fibrillation and electric countershocks during coronary artery bypass operations--association with postoperative CK-MB release

Reperfusion ventricular fibrillation during coronary artery bypass surgery is common and electric shocks are often needed to terminate it. Both the fibrillation and the reversing electric shocks are potentially detrimental to the myocardium. In 61 aortocoronary bypass patients with uncomplicated clinical course (no difficulties in weaning from bypass, no ECG changes and no inotropic medication), serial creatine kinase-MB values were recorded. Evaluated explanatory variables were patient age, ejection fraction, aortic occlusion time, perfusion time, number of peripheral anastomoses and of anastomoses to marginal branches, myocardial fibrillation time before aortic cross-clamping, after cross-clamping prior to cardiac arrest and after declamping, and number of defibrillations. The results indicated that reperfusion fibrillation times up to 10 minutes are not harmful, provided that left ventricular decompression is carried out. Too early and thus numerous defibrillations raise creatine kinase-MB levels and probably also damage the myocardium, and therefore should be avoided.

Lidocaine cardioplegia for prevention of reperfusion ventricular fibrillation

Lidocaine addition to crystalloid cardioplegic solution for prevention of reperfusion ventricular fibrillation after the release of the aortic cross-clamp was studied in 50 patients undergoing coronary artery bypass grafting and in 30 patients undergoing mitral or aortic valve replacement. Twenty-six of the patients undergoing coronary artery bypass grafting received lidocaine, 100 mg/L of cardioplegia, whereas a control group of 24 patients received cardioplegia without lidocaine. In the group undergoing valve replacement, 14 patients received lidocaine cardioplegia and 16 patients served as control. In the coronary artery bypass grafting group, lidocaine cardioplegia reduced significantly the incidence of reperfusion ventricular fibrillation from 100% to 42%. In the valve group, lidocaine cardioplegia also reduced significantly the incidence of reperfusion ventricular fibrillation from 93% to 42%. In both groups, lidocaine cardioplegia decreased the number of direct-current countershocks required to defibrillate the heart, with no significant increase in the incidence of high-grade atrioventricular block.

Comparison of bretylium and lidocaine in the prevention of ventricular fibrillation after aortic cross-clamp release in coronary artery bypass surgery

The authors compared bretylium and lidocaine for reducing the incidence and persistence of ventricular fibrillation following aortic cross-clamp release performed during coronary artery bypass surgery. Thirty-three adult patients scheduled for elective bypass surgery were randomly assigned in a double-blind fashion to receive a bolus of bretylium, 10 mg/kg, lidocaine, 2 mg/kg, or saline, in equal volumes prior to the release of the aortic cross-clamp. Coronary artery bypass surgery was conducted using standard cardiopulmonary bypass (CPB) procedures with systemic cooling to 24 degrees to 28 degrees C. Temperature, arterial blood gases, and electrolytes were recorded. After clamp release, the first electrical rhythm was noted. Abnormal rhythms (ventricular fibrillation) were allowed to persist for 1 to 2 minutes, and if spontaneous conversion to a supraventricular rhythm did not occur, defibrillation with internal DC countershocks was applied. Patients were compared with respect to occurrence of ventricular fibrillation, need for DC countershocks, antiarrhythmic drugs, and inotropic support. There was no significant difference among the groups with respect to age, sex, preoperative medications, past medical histories, ejection fractions, average number of bypasses, cross-clamp times, or temperatures during bypass. The incidence of ventricular fibrillation after aortic cross-clamp removal was: saline 91%, lidocaine 64% (P less than 0.01), and bretylium 36% (P less than 0.01). The number of countershocks required to defibrillate, while lower in the bretylium group, did not reach statistical significance. After cardiopulmonary bypass, cardiac output and systemic vascular resistance were comparable. Bretylium warrants further study in this setting.

The influence of age and dietary fat in an animal model of sudden cardiac death

The influence of dietary fat on myocardial vulnerability to arrhythmia was examined using coronary artery occlusion and reperfusion in the anesthetised rat as a whole animal model of ventricular fibrillation and sudden cardiac death. Animals were fed a reference (REF) diet alone or supplemented 12% by weight with tuna fish oil (TFO) (rich in n-3 fatty acids), sunflower seed oil (SSO) (rich in n-6 fatty acids) or sheep perirenal fat (SF) (rich in saturated fatty acids). Feeding periods of 6, 12, and 18 months and a total of 108 rats were used. The incidence of ventricular fibrillation in occlusion was reduced from 46% of REF animals to 6% and 21% in TFO and SSO groups respectively and increased to 68% in the SF-fed rats. The incidence of ventricular tachycardia was also reduced by TFO and SSO. The duration of arrhythmic episodes was increased by SF and reduced by TFO and SSO. The incidence of fibrillation on reperfusion of acutely ischemic myocardium (15 minutes occlusion) was significantly reduced by TFO only (12%, REF = 50%, SSO = 30%, SF = 70%). Severity of arrhythmias increased with age as did the extent of dietary influence. Mortality from fibrillation which only occurred in rats aged 12 months or older (REF = 13%) was increased by SF (43%) mainly in reperfusion (38%) but did not occur in TFO or SSO. These results indicate the potential benefit of dietary modification to include a higher proportion of polyunsaturated fat especially fish oil in reducing risk of sudden cardiac death.(ABSTRACT TRUNCATED AT 250 WORDS)

Technique and results with a roller pump left and right heart assist device

During the last 10 years we have inserted a roller pump-driven left heart assist device in 72 patients and a right heart assist device in 7 patients for profound heart failure after a variety of cardiac surgical procedures. In addition a percutaneous left heart assist device (transseptal insertion of left atrial cannula via a femoral vein) was employed in 5 patients with profound cardiogenic shock after acute myocardial infarction. Thirty patients (41.7%) were weaned from the left heart assist device and 21 (29.2%) were discharged from the hospital. Two patients (40.0%) were weaned from the right heart assist device, but both later died during the postoperative period. Of the 5 patients in whom a percutaneous left heart assist device was inserted, 4 underwent successful emergency percutaneous transluminal coronary angioplasty, but all 5 patients died. Causes of death included severe coagulopathy, irreversible extensive myocardial infarction and cardiac failure, refractory arrhythmias, severe "shock" lung, and multisystem failure. In summary, satisfactory results can be achieved with a roller pump-driven left and right heart assist device for severe postoperative heart failure. Further experience should be obtained with the percutaneous technique to assess its efficacy in treating patients with acute myocardial infarction and cardiogenic shock.