Risk Prediction in Children With Congenital Heart Disease: Business As Usual—Or Not?

See Article, p 1083 Successful practice at pediatric specialty hospitals depends on the safe anesthetic care of children with or without congenital heart disease (CHD). Skilled and experienced anesthesia providers safely manage and transition a pediatric patient through all perioperative phases. Preoperatively, it is important to perform a thorough assessment of the patient’s status. This enables the anesthesiologist to formulate an anesthetic plan, to address contingencies, and to prepare for potential problems that may arise. Pediatric anesthesiologists are caring for increasingly complex patients who require preoperative optimization of existing medical problems. Parents and caretakers rightfully expect to be counseled about risks and possible adverse outcomes. It is equally important to consider health care resource utilization during decision-making process for postoperative patient placement, discharge, and follow-up. For pediatric anesthesia practice, the Anaesthesia PRactice In Children Observational Trial (APRICOT) has demonstrated that participation of a senior, experienced anesthesiologist can reduce the likelihood of adverse events in the perioperative period.1 Faraoni et al,2 in this issue of Anesthesia& Analgesia, address a specific patient population that carries a higher-than-average risk for perioperative complications: pediatric patients with CHD who undergo noncardiac surgery. In a previous publication, these authors developed and validated a risk stratification score for children with CHD undergoing noncardiac surgery.3 Eight factors were identified as significant predictors for in-hospital mortality: emergency procedure, severe CHD, single ventricle physiology, previous surgery within 30 days, need for inotropic support, need for preoperative cardiopulmonary resuscitation (CPR), presence of acute or chronic kidney injury, and need for perioperative mechanical ventilation. In the current article, “Integration of the Intrinsic Surgical Risk With Patient Comorbidities and Severity of Congenital Cardiac Disease Does Not Improve Risk Stratification in Children Undergoing Noncardiac Surgery,” the authors raise the question whether addition of intrinsic surgical risk improves the previously established risk stratification system.2 For this latest study, the authors used the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) pediatric database to obtain a derivation cohort using pediatric surgical patients between 2012 and 2016 and a validation cohort with patients drawn from the year 2017. Multivariable logistic regression analysis revealed that unrepaired CHD, severe CHD (defined as uncorrected cyanotic heart disease, documented pulmonary hypertension, ventricular dysfunction requiring medications or listed for heart transplant), emergent procedure, preoperative CPR, inotropic support, acute or chronic kidney injury, and mechanical ventilation were significant independent predictors of 30-day mortality. Interestingly, high surgical risk was associated with decreased odds for 30-day mortality. This current article2 is important for 2 reasons. It confirms many risk predictors that have been identified by previous studies, including the author’s study from 2016, using a large derivation and a separate, equally robust, validation cohort. Additionally, it challenges the assumption―in part derived from adult data and literature―that intrinsic surgical risk is a predominant predictor of 30-day mortality for pediatric patients with CHD who undergo noncardiac procedures. In the adult population, many validated risk stratification systems utilize intrinsic surgical risk in one form or another. These include risk prediction scores like the American Society of Anesthesiologists physical status (ASA-PS) score4 and the Lee Revised Cardiac Risk Index5 and risk prediction models like the Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM)6 and its variant, the Portsmouth POSSUM (P-POSSUM)7; the Surgical Risk Scale (SRS)8; and the Donati Surgical Risk Score.9 For pediatric patients undergoing noncardiac surgery, studies have similarly observed that intrinsic surgical risk is a predictor of mortality10 and unplanned readmissions11 and that risk prediction models like the neurological, airway, respiratory, cardiovascular, other surgical severity (NARCO-SS)12 require input of surgical severity. Intrinsic surgical or, in this setting, the procedure risk category is a main component of the Catheterization Risk Score for Pediatrics (CRISP), which predicts the risk of serious adverse events for individual pediatric patients with CHD undergoing cardiac catheterization procedures.13 Knowledge accumulated over decades has resulted in the contemporary approach to the preoperative assessment of pediatric cardiac patients before surgical procedures. At many pediatric hospitals, the patients are seen and evaluated by a dedicated pediatric cardiac anesthesiology consultation service within a pediatric preoperative assessment center. Data from a recent visit with the primary pediatric cardiologist are integrated with clinical evaluations from the patient’s primary care provider and other subspecialty consultants. A comprehensive preoperative evaluation should include the review of pertinent cardiac studies, including imaging (echocardiography, computed tomography, cardiac magnetic resonance imaging), electrocardiography, electrophysiology, and cardiac catheterization data. In patients with repaired or palliated CHD, the cardiac surgeon’s previous operative notes can provide a better understanding of the current anatomy and potential problems to be encountered intraoperatively. Assessment of the patient should include a survey of all organ functions, with a specific focus on the airway and cardiovascular/pulmonary systems. Elucidating chronic exertional capacity and functional limitations in older patients, along with any recent deterioration, can reflect acute cardiopulmonary changes and trigger direct communication with the pediatric cardiologist so that further evaluation and optimization can be achieved. Results by Faraoni et al2 diverge from existing risk assessment knowledge insofar that higher intrinsic surgical risk conferred a lower odds ratio for 30-day mortality. The reasons for this finding are obscure and remain speculative. While intrinsic surgical risk cannot be ignored, Faraoni et al2 reported in their study that a specific focus should be placed on the patient’s overall condition, including current anatomy of the CHD defect, history of surgical repair or palliation, possible residual lesions, and functional status. Interestingly, a paper by Hennein et al14 published in 1994 reached a similar conclusion: “[…] physiologically well-compensated patients with CHD can undergo elective operations at a low operative risk; however, poorly compensated patients undergoing urgent or emergent operations are at high risk.” In conclusion, using currently proposed risk stratification by Faraoni et al2 can aid in decisions about health care resource allocation. Not only will it guide the informed consent process with caretakers, the newly discovered finding that intrinsic surgical risk does not alter risk stratification in children with CHD undergoing noncardiac surgery will also allow procedures to be undertaken based on the severity of the CHD in the patient. This underscores the importance of further investigations into the interplay between surgical and patient factors.Figure.: Stratification of patient risk in children with CHD undergoing noncardiac surgery. The risk is lowest in children with minor (green) CHD when compared to those with major (yellow) and severe (red) CHD. The 30-day noncardiac surgical mortality risk increases with presence of comorbidities and need for mechanical or inotropic support. *CHD. †Comorbidities = prematurity, chronic lung disease, acute or chronic kidney injury, sepsis and emergent procedure; additional support = inotropes, mechanical ventilation, preoperative CPR. ASD indicates atrial septal defect; CHD, congenital heart disease; CPR, cardiopulmonary resuscitation; CV, cardiovascular; HLHS, hypoplastic left heart syndrome; PI, pulmonary insufficiency; TOF, tetralogy of Fallot; VSD, ventricular septal defect.We suggest the use of a schematic to stratify patient risk when evaluating patients with CHD requiring noncardiac surgery. As displayed here in the Figure, risk varies based on the severity of CHD and the risk changes depending on the presence or absence of comorbidities and the need for additional support―specifically the use of inotropes, mechanical ventilation, or need for preoperative CPR. Finally, to accept the results of the present study by Faraoni et al,2 there must be an underlying assumption that most children with complex CHD undergoing noncardiac surgery will be cared for by providers with significant expertise and experience. DISCLOSURES Name: Benjamin Kloesel, MD, MSBS. Contribution: This author wrote, revised, and approved the manuscript. Name: Nikolaos J. Skubas, MD, DSc, FASE, FACC. Contribution: This author provided the edits and revised and approved the manuscript. Name: Kumar Belani, MBBS, MS, FACA, FAAP. Contribution: This author provided guidance, edited the references, did the figure and the final edits, and approved the manuscript. This manuscript was handled by: Thomas R. Vetter, MD, MPH.