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.

The mid-term outcome of interventricular septal hematoma after ventricular septal defect closure

We present the case report of a patient who developed interventricular septal hematoma as a complication during perimembranous ventricular septal defect closure. Although cardiopulmonary bypass was re-established and the hematoma was aspirated, postoperative echocardiography revealed that the hematoma reaccumulated in the interventricular septum. She suffered from low-cardiac-output syndrome for 1 week requiring a large amount of inotropic agents. Postoperative echocardiography revealed that the interventricular septal hematoma gradually disappeared. At 1 year follow-up, 99mTc-tetrofosmin myocardial single-photon emission computed tomographic revealed myocardial ischemia in the inferior and septal walls. At 4 years follow-up, her cardiac function has gradually improved. She has no symptoms of heart failure with angiotensin-converting enzyme inhibitor and beta-blocker.

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.

Cardiac resynchronisation therapy in a pace-dependent infant with tetralogy of Fallot

We present the case of a 5-month-old infant with tetralogy of Fallot and congenital atrio-ventricular block that developed severe left ventricular dysfunction during apical left ventricular pacing, in which cardiac resynchronisation therapy was used as an emergency procedure due to persistent low cardiac output syndrome.

The multivariable prognostic models for severe complications after heart valve surgery

Background To provide multivariable prognostic models for severe complications prediction after heart valve surgery, including low cardiac output syndrome (LCOS), acute kidney injury requiring hemodialysis (AKI-rH) and multiple organ dysfunction syndrome (MODS). Methods We developed multivariate logistic regression models to predict severe complications after heart valve surgery using 930 patients collected retrospectively from the first affiliated hospital of Sun Yat-Sen University from January 2014 to December 2015. The validation was conducted using a retrospective dataset of 713 patients from the same hospital from January 2016 to March 2017. We considered two kinds of prognostic models: the PRF models which were built by using the preoperative risk factors only, and the PIRF models which were built by using both of the preoperative and intraoperative risk factors. The least absolute shrinkage selector operator was used for developing the models. We assessed and compared the discriminative abilities for both of the PRF and PIRF models via the receiver operating characteristic (ROC) curve. Results Compared with the PRF models, the PIRF modes selected additional intraoperative factors, such as auxiliary cardiopulmonary bypass time and combined tricuspid valve replacement. Area under the ROC curves (AUCs) of PRF models for predicting LCOS, AKI-rH and MODS are 0.565 (0.466, 0.664), 0.688 (0.62, 0.757) and 0.657 (0.563, 0.751), respectively. As a comparison, the AUCs of the PIRF models for predicting LOCS, AKI-rH and MODS are 0.821 (0.747, 0.896), 0.78 (0.717, 0.843) and 0.774 (0.7, 0.847), respectively. Conclusions Adding the intraoperative factors can increase the predictive power of the prognostic models for severe complications prediction after heart valve surgery.

Biomarkers in low cardiac output syndrome after open cardiac surgery in children

Background Corrective cardiac surgery is the standard management for complex congenital heart disease. Cardiopulmonary bypass surgery and post-surgical intensive care may lead to low cardiac output syndrome (LCOS), as a major complication after open heart surgery. To diagnose early LCOS, lactate level, pCO2 gap, and mixed venous oxygen saturation (SvO2) are parameters reported to have correlations with decreased cardiac output, morbidity, and post-cardiac surgery mortality. Objective To determine the usefulness of lactate level, pCO2 gap (arterial-vein), and SvO2 for early detection of LCOS in children post-open heart surgery. Methods This prospective cohort study was done from August to October 2017 in the ICU of the Integrated Cardiac Center, Dr. Cipto Mangunkusumo Hospital, Jakarta. Subjects were pediatric patients who underwent cardiac surgery. After surgery, patients underwent monitoring in the ICU for clinical signs of LCOS and examinations for lactate levels, pCO2 gap, and SvO2 at 15 minutes, 4 hours and 8 hours. Results Thirty-three open heart surgery patients were the subjects. Lactate level at 4 hours and 8 hours post-operative were significantly higher in the LCOS group compared to non-LCOS group. For the pCO2 gap, only the 4-hour post-operative results were significantly higher in LCOS group compared to non-LCOS groups. In addition, only SvO2 at 4 hours after surgery was significantly lower in LCOS group compared to non-LCOS group. Conclusion Elevated lactate, high pCO2 gap, as well as decreased SvO2 at 4 hours post-operatively are the most reliable markers of LCOS after pediatric open heart surgery.

Impact of Cone vs. Hetzer Repair on Postoperative Outcomes in Patients With Ebstein's Anomaly: 10-Year Experience From a Single Institution

Objective: The aim of this study was to compare the early outcomes of the cone and Hetzer procedures for Ebstein's malformation.Methods: This retrospective study included patients who underwent either cone (n = 83) or Hetzer repair (n = 45) with Ebstein's malformation from January 2011 to December 2020.Results: One early death occurred in the cone group due to low cardiac output syndrome. Five cone and three Hetzer repair patients required reoperation before discharge. At discharge, the cone group had a better reduction in tricuspid valve regurgitation (TR) than the Hetzer group (74.7 vs. 51.1%, p = 0.009). Two patients in the cone group and seven patients in the Hetzer group required reoperation &gt;30 days after their initial surgery. The cone group with no/mild TR was 75.6%, and the Hetzer group was 48.9% at the time of last follow-up (p = 0.010).Conclusion: Short-term outcomes of the cone repair are better than the Hetzer procedure. The cone repair should be the better option among patients with Ebstein's malformation who need surgical intervention.