Pharmacologic therapies for the low cardiac output syndrome in children after cardiac surgery: evidence of their efficacy and trends in their use

The low cardiac output syndrome describes the phenomenon of the reduction of cardiac output that can occur following cardiac surgery requiring cardiopulmonary bypass. If unrecognized or untreated, this condition can result in significant morbidity and mortality. Along with non-pharmacologic therapies, pharmacologic agents used to help manage the low cardiac output syndrome include catecholamine inotropes, inodilators, systemic vasodilators, pulmonary vasodilators, and other classes of medications. We summarize the rationale and key evidence supporting the use of these therapies in children. In addition, utilizing provider surveys and registry reviews, we describe the current trends in the use of these medications and the variation demonstrated between providers and centers. Given the heterogeneous etiology of low cardiac output syndrome, successful management requires that pharmacologic therapies be tailored to the physiologic derangements of each patient.

Preoperative Left Ventricle End Diastolic Volume Index as a Predictor for Low Cardiac Output Syndrome After Surgical Closure of Secundum Atrial Septal Defect With Small-Sized Left Ventricle

Introduction: Low cardiac output syndrome is one of the postoperative complications that are associated with significant morbidity and mortality after surgical closure of atrial septal defect (ASD) with small-sized left ventricle (LV). This study investigated whether preoperative left ventricular end-diastolic volume index (LVEDVi) could accurately predict low cardiac output syndrome (LCOS) after surgical closure of ASD with small-sized LV.Method: This retrospective cohort study involved adult ASD patients with small-sized LV from January 2018 to December 2019 in National Cardiovascular Center Harapan Kita. Preoperative MRI data to assess the left and right ventricle volume were collected. A bivariate analysis using independent Student's t-test was done. Diagnostic test using receiver operating characteristic (ROC) curve was also done to obtain the area under the curve (AUC) value. The best cutoff point was determined by Youden's index.Result: Fifty-seven subjects were involved in this study [age (mean ± SD) 32.56 ± 13.15 years; weight (mean ± SD) 48.82 ± 12.15 kg]. Subjects who had post-operative LCOS (n = 30) have significantly lower LVEDVi (45.0 ± 7.42 ml/m2 vs. 64.15 ± 13.37 ml/m2; p < 0.001), LVEDV (64.6 ± 16.0 ml vs. 85.9 ± 20.7 ml; p < 0.001), LVSV (38.97 ± 11.5 ml vs. 53.13 ± 7.5 ml; p < 0.001), and LVSVi (27.28 ± 8.55 ml/m2 vs. 37.42 ± 5.35 ml/m2; p < 0.001) compared to subjects who did not have post-operative LCOS (n = 27). ROC analysis showed that the best AUC was found on LVEDVi (AUC 95.3%; 95% confidence interval: 90.6–100%). The best cutoff value for LVEDVi to predict the occurrence of LCOS after surgical closure of ASD was 53.3 ml/m2 with a sensitivity of 86.7% and a specificity of 85.2%.Conclusion: This study showed that preoperative LVEDVi could predict LCOS after surgical closure of ASD with small-sized LV with a well-defined cutoff. The best cutoff value of LVEDVi to predict the occurrence of LCOS after surgical ASD closure was 53.5 ml/m2.

Diagnosis of pulmonary hypertension associated with congenital heart disease. Part 1. Definition, classification and initial examination of patients

Having discussed current definitions and classification of pulmonary hypertension associated with congenital heart defects, the authors consider characteristic clinical symptoms and data of physical examination separately for every subgroup. An increase in pulmonary vascular resistance after radical correction and with small / concomitant defects leads to insufficient filling of the systemic ventricle and the progression of symptoms of low cardiac output , i.e. shortness of breath, palpitations, fatigue, weakness and decreased exercise tolerance. At late stages, due to transient systemic hypotension the patients feel dizziness, lightheadedness and fainting, as well as signs of congestive right ventricular failure – peripheral edema, liver enlargement, ascites and swelling of the cervical veins. The patients with Eisenmenger syndrome develop cyanosis and signs of systemic complications – polycythemia, deformation of the distal phalanges of the fingers like «drumsticks» and «watch glasses», posture disturbance due to osteoarthropathy and scoliosis, pulmonary and paradoxical systemic thrombosis and embolism, bleeding, symptoms of gout and cholelithiasis, impaired renal function. Even mild pulmonary hypertension after Fontaine’s surgery causes venous hypertension with congestive heart failure, hydrothorax, protein deficiency enteropathy and plastic bronchitis, as well as insufficient blood flow to the systemic ventricle with low cardiac output, shortness of breath, palpitations, fatigue, weakness and decreased exercise tolerance. All forms of pulmonary hypertension cause pain in the region of the heart, hemoptysis, pulmonary hemorrhage, arrhythmias, and developmental delay in children. The patient shall be examined «from head to toe.» The diagnostic value of auscultation depends on the complexity of the congenital malformation leading to pulmonary hypertension Pulse oximetry should be performed separately on the arms and legs at rest and exercise.

Del Nido versus HTK cardioplegia for myocardial protection during adult complex valve surgery: a retrospective study

Background Histidine-tryptophan-ketoglutarate (HTK) and del Nido (DN) cardioplegia are intracellular-type and extracellular-type solution respectively, both can provide a long period of myocardial protection with single-dose infusion, but studies comparing the two are rare for adult cardiac surgery. This study aims to evaluate whether DN is suitable for cardioplegia in complex and high-risk valve surgery with long-term cardiac ischemia when compared with HTK. Methods The perioperative records of adult patients infused with DN/HTK as a cardioplegic solution who underwent complex valve surgery with an expected myocardial ischaemic duration longer than 90 min between Oct 2018 and Oct 2019 were analysed retrospectively. Results Of the 160 patients who received DN/HTK and underwent complex valve surgery, we propensity matched 73 pairs. Both groups achieved satisfactory cardiac arrest effects, and no significant difference was found in their cTnI and CK-MB levels within 12 to 72 h postoperatively. The DN group had a higher rate of return to spontaneous rhythm (0.88 v 0.52, P < 0.001), a lower frequency of postoperative severe arrythmias (12% v 26%, P = 0.036), a higher postoperative stroke volume (65 v 59 ml, P = 0.011) and a higher cardiac output (6.0 v 4.9 L/min, P = 0.007) as evaluated by echocardiography, fewer transfusions and shorter ICU stays (both P < 0.05). The two groups had similar inotrope usage and similar incidences of low cardiac output, morbidities and mortality. Subgroup analysis showed that when the aortic clamping time was greater than 120 min, the advantages of DN were weakened. Conclusions DN can be safely applied to complex valve surgery, and it has a similar myocardial protection effect as HTK. Further prospective studies are required to verify these retrospective findings. Trial registration retrospectively registered.

271 Treatment of thrombophlebitic necrotic lesions in a patient with syncardia—a case report

Aims The 58 years old male patient with an important dilated cardiomyopathy, carrier of ICD, numerous malignant arrhythmias (VT) and without the possibility of a timely heart transplant, underwent emergency surgery by implanting a total artificial heart syncardia. Necrotic tissue was already present on the forearm and in the antecubital region before the surgery; it was caused by extravasation and thrombophlebitis due to continuous intravenous therapies and the lesions were deep down to tendons and bones after a surgical toilet. Years of unstable haemodynamics caused by dilated cardiomyopathy and low cardiac output led to poor peripheral vascularization giving priority to noble structures. Restoration of the tissue using advanced dressings without the use of skin grafts avoiding bacterial infections in a fragile patient. Methods and results A Pubmed search for advanced dressings was performed and a Webinar on the Wound Hygiene technique was attended. In the first instance, a polyurethane foam dressing was used and the wound on the forearm showed major improvements, subsequently with the synergistic help of the ‘Wound Hygiene’ technique and dressings based on connectivine, the tissue healed. The wound located in the antecubital region had continuous biofilm formation and a VacTherapy was planned for this. After 7 days, the conditions worsened and for this reason it was decided to use the Aqua Cell Ag +. This dressing with the silver helps in the formation of granulation tissue and it also prevents infections ‘trapping’ bacteria inside it. Conclusions The use of dressings with the Wound Hygiene technique led to the formation of new tissue without the need to perform a skin graft in a patient with a total artificial heart and without bacterial infections.

Analysis of Risk Factors of Postoperative Neurological Complications in Patients with Stanford Type A Aortic Dissection Undergoing Sun’s Procedure

Objective: This study analyzed the risk factors of neurological complications in patients with Stanford type A aortic dissection after Sun’s procedure in a single-center with the purpose of improving the effects. Methods: From January 2019 to December 2020, the clinical data of 480 patients with Stanford type A aortic dissection, who were treated by Sun’s procedure in our center were retrospectively analyzed. Univariate and multivariate logistic regression analyses were used to determine the risk factors of postoperative neurological complications. According to whether there were neurological complications after surgery, they were divided into two groups: the group with complications (n=70) and the group without complications (n=410). The clinical data of the two groups were collected and compared. Results: There were 70 cases of patients with postoperative neurological complications in 480 cases. The incidence rates of temporary neurological dysfunction (TND) and permanent neurological dysfunction (PND) was 11.5% (55/480) and 3.1% (15/480), respectively. Univariate analysis showed that the age (? 70 years), stroke history, femoral artery intubation and cardiopulmonary bypass (CPB) time were associated with postoperative PND (p < 0.05). Renal dysfunction, emergency surgery, postoperative hypernatremia, postoperative hyperglycemia, postoperative hypoxemia, postoperative low cardiac output syndrome, and assisted time of suction influenced the occurrence of postoperative TND (p < 0.05). Multivariate logistic regression analysis showed that age (? 70 years), stroke history, femoral artery intubation and CPB time were independent risk factors for PND. Renal dysfunction, emergency surgery, postoperative hypernatremia, postoperative hyperglycemia, postoperative hypoxemia, postoperative low cardiac output syndrome, and aspiration time were independent risk factors for TND. Compared with the two groups, the hospitalization time and ICU time of the patients in the neurological complications group were significantly prolonged, and the mortality rate was significantly increased (p < 0.05). Conclusion: There are many risk factors for neurological complications in patients with Stanford type A aortic dissection after surgery. With the improvement of surgical techniques, optimization of cerebral perfusion, and interventions for risk factors, Sun’s procedure remains the preferred treatment for Stanford type A aortic dissection.

Construction and Application of a Model for Predicting the Risk of Delirium in Postoperative Patients With Type a Aortic Dissection

Background: Postoperative delirium (POD), an alteration in a patient's consciousness pattern, can affect the treatment and prognosis of a disease.Objective: To construct a prediction model for delirium in patients with type A aortic dissection after surgery and to validate its effectiveness.Methods: A retrospective cohort design was used to study 438 patients undergoing surgical treatment for type A aortic dissection from April 2019 to June 2020 in tertiary care hospitals. POD (n = 78) and non-delirium groups (n = 360) were compared and analyzed for each index in the perioperative period. A prediction model was established using multifactorial logistic regression, and 30 patients' perioperative data were collected for model validation.Results: Eight predictors were included in this study: smoking, diabetes, previous cardiovascular surgery, ejection fraction (EF), time to aortic block, acute kidney injury, low cardiac output syndrome, and pulmonary complications. The area under the receiver operating characteristic (ROC) curve of the constructed prediction model was 0.98 ± 0.005, and the Youden index was 0.91. The validation results showed 97% sensitivity, 100% specificity, and 93% accuracy. The expression of the model was Z = Smoking assignment* – 2.807 – 6.009*Diabetes assignment – 2.994*Previous cardiovascular surgery assignment – 0.129*Ejection fraction assignment + 0.071*Brain perfusion time assignment – 2.583*Acute kidney injury assignment – 2.916*Low cardiac output syndrome assignment – 3.461*Pulmonary related complications assignment + 20.576.Conclusion: The construction of an effective prediction model for the risk of delirium in patients after type A aortic stratification can help identify patients at high risk of POD early. It also provides a reference for healthcare professionals in the prevention and care of these patients.

To Balloon or Not to Balloon? The Effects of an Intra-Aortic Balloon-Pump on Coronary Artery Flow during Extracorporeal Circulation Simulating Normal and Low Cardiac Output Syndromes

ECMO is the most frequently used mechanical support for patients suffering from low cardiac output syndrome. Combining IABP with ECMO is believed to increase coronary artery blood flow, decrease high afterload, and restore systemic pulsatile flow conditions. This study evaluates that combined effect on coronary artery flow during various load conditions using an in vitro circuit. In doing so, different clinical scenarios were simulated, such as normal cardiac output and moderate-to-severe heart failure. In the heart failure scenarios, we used peripheral ECMO support to compensate for the lowered cardiac output value and reach a default normal value. The increase in coronary blood flow using the combined IABP-ECMO setup was more noticeable in low heart rate conditions. At baseline, intermediate and severe LV failure levels, adding IABP increased coronary mean flow by 16%, 7.5%, and 3.4% (HR 60 bpm) and by 6%, 4.5%, and 2.5% (HR 100 bpm) respectively. Based on our in vitro study results, combining ECMO and IABP in a heart failure setup further improves coronary blood flow. This effect was more pronounced at a lower heart rate and decreased with heart failure, which might positively impact recovery from cardiac failure.

N-Terminal Pro-B-Type Natriuretic Peptide as a Predictor of Adverse Outcomes After Off-Pump Coronary Artery Bypass Surgery: A Prospective Study

Background: The strength of association between preoperative natriuretic peptide levels and adverse outcomes after cardiac surgery recently has been studied in different research, but results still are diversely variable. Methods: Sixty-five consecutive patients undergoing elective off-pump coronary artery bypass grafting prospectively were recruited. Preoperative levels of NTproBNP were measured in venous blood samples collected before induction of anesthesia. Results: The average age was 57.62 ± 7.21. Of the patients, 86.15% were male. Euro-scoreII averaged 1.76 ± 0.34. The mean preoperative NTproBNP levels were 312.41 ± 329.93 pg/mL. Only two patients died (3%). Three patients required prolonged mechanical ventilation (4.6%). Four patients (6%) suffered from new onset postoperative AF. Five patients (7.6%) had low cardiac output, of which three needed IABP, and four patients (6%) had postoperative myocardial infarction. The mean ICU stay was 3.37 ± 0.84 days, and the mean hospital stay was 6.38 ± 1.3 days. There were no significant differences in preoperative NTproBNP levels in patients who had or didn’t have any of the postoperative complications or in-hospital mortality (P > .05). Conclusion: Our study showed no significant correlation between preoperative NTproBNP levels and postoperative low cardiac output, atrial fibrillation, postoperative myocardial infarction, length of ICU stay, prolonged mechanical ventilation, length of hospital stay as well as in-hospital mortality following elective off-pump CABG. Therefore, more prospective specific studies are needed to delineate the role of preoperative natriuretic peptides as significant predictors of poor outcomes after CABG surgery.