Fatal cardiac arrest in pediatric heart transplant recipients: Query of the UNOS database

Risk factors and outcomes of sudden cardiac arrest in pediatric heart transplant recipients

BACKGROUND

Sudden cardiac arrest (SCA) is a prevailing cause of mortality after pediatric heart transplant (HT) but remains understudied. We analyzed the incidence, outcomes, and risk factors for SCA at our center.

METHODS

Retrospective review of all pediatric HT patients at our center from January 1, 2009 to January 1, 2021. SCA was defined as an abrupt loss of cardiac function requiring cardiopulmonary resuscitation and/or mechanical circulatory support (MCS). Events that occurred in the setting of limited resuscitative wishes, or while on MCS were excluded. Patient characteristics and risk factors were analyzed.

RESULTS

Fourteen of 254 (6%) experienced SCA at a median of 3 (1, 4) years post-HT. Seven (50%) events occurred out-of-hospital. Eleven (79%) died from their initial event, 2 (18%) after failure to separate from extracorporeal membrane (ECMO). In univariate analysis, black race, younger donor age, prior acute cellular rejection (ACR) episode, pacemaker and/or ICD in place, and pre-mortem diagnosis of allograft vasculopathy were associated with SCA (P = .003-0.02). In multivariable analysis, history of ACR, younger donor age, and black race retained significance. [OR = 6.3, 95% CI: 1.6-25.4, P = .01], [OR = 0.9, 95% CI: 0.8-1, P = .04], and [OR = 7.3, 95% CI: 1.1-49.9, P = .04], respectively. SCA occurred in 3 patients with a functioning ICD or pacemaker, which failed to restore a perfusing rhythm.

CONCLUSIONS

SCA occurs relatively early after pediatric HT and is usually fatal. Half of events happen at home. Those who received younger donors, have a history of ACR, or are of black race are at increased risk. ICDs/pacemakers may offer limited protection.

Emergency Department Management of Pediatric Heart Transplant Recipients: Unique Immunologic and Hemodynamic Challenges

BACKGROUND

Since the first heart transplant in 1967, there has been significant progress in this field of cardiac transplantation. Approximately 600 pediatric heart transplants are performed every year worldwide. With the increasing number of pediatric heart transplant patients, and given the few tertiary care pediatric transplant centers, adult and pediatric emergency department (ED) providers are increasingly engaged in the care of pediatric heart transplant recipients in the ED.

OBJECTIVE

The aim of this article is to review common ED scenarios pertinent to the pediatric heart transplant patients.

DISCUSSION

There are complications unique to this population, such as rejection, opportunistic infections, and medication side effects, that require special considerations, and it is helpful for the emergency medicine (EM) provider to have knowledge about them.

CONCLUSIONS

The unique immunological challenges in these patients, including rejection and medication side effects and opportunistic infections, make this population fragile, and the knowledge of these challenges is helpful for EM providers.

Permanent pacemaker implantation in pediatric heart transplant recipients: A systematic review and evidence quality assessment

Bradyarrhythmias are a common complication following pediatric OHT and may require permanent pacemaker implantation (PPM). The purpose of this study was to investigate the incidence, predictors, and outcomes of children undergoing PPM implantation following OHT. A PRISMA-compliant systematic literature review was performed using the PubMed database and the Cochrane Library (end-of-search date: January 27, 2019). The Newcastle-Ottawa scale and the Joanna Briggs Institute tool were used to assess the quality of cohort studies and case reports, respectively. We analyzed data from a total of 11 studies recruiting 7198 pediatric patients who underwent heart transplant. PPM implantation was performed in 1.9% (n = 137/7,198; 95% CI: 1.6-2.2) of the patients. Most patients underwent dual-chamber pacing (46%, 95% CI: 32.6-59.7). Male-to-female ratio was 1.3:1. Mean patient age at the time of OHT was 10.1 ± 6.3. Overall, biatrial anastomosis was used in 62.2% (95% CI: 52.8-70.6) of the patients. The bicaval technique was performed in the remaining 37.8% (95% CI: 29.4-47.1). Sinus node dysfunction was the most frequent indication for PPM implantation (54.4%; 95% CI: 42.6-65.7) followed by AV block (45.6%; 95% CI: 34.3-57.3). The median time interval between OHT and PPM implantation ranged from 17 days to 12.5 years. All-cause mortality was 27.9% (95% CI: 18.6-39.6) during a median follow-up of 5 years. PPM implantation is rarely required after pediatric OHT. The most common indication for pacing is sinus node dysfunction, and patients undergoing biatrial anastomosis may be more likely to require PPM.

Cardiac Arrest in the Pediatric Cardiac ICU: Is Medical Congenital Heart Disease a Predictor of Survival?

OBJECTIVES

Children with medical cardiac disease experience poorer survival to hospital discharge after cardiopulmonary arrest compared with children with surgical cardiac disease. Limited literature exists describing epidemiology and factors associated with mortality in this heterogeneous population. We aim to evaluate the clinical characteristics and outcomes after cardiopulmonary arrest in medical cardiac patients.

DESIGN

We performed a retrospective review of pediatric cardiac patients who underwent cardiopulmonary resuscitation in a tertiary care cardiac ICU. Surgical cardiac patients underwent cardiac surgery immediately prior to ICU admission. Nonsurgical cardiac patients were divided into two groups based on the presence of congenital heart disease: congenital heart disease medical or noncongenital heart disease medical. Clinical and outcome variables were collected. Primary outcome was survival to hospital discharge.

SETTINGS

Texas Children's Hospital cardiac ICU.

PATIENTS

Patients admitted to Texas Children's Hospital cardiac ICU between January 2011 and December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 150 cardiopulmonary arrest events reviewed, 90 index events were included (46 surgical, 26 congenital heart disease medical, and 18 noncongenital heart disease medical). There was no difference in primary outcome among the three groups. The absence of an epinephrine infusion precardiopulmonary arrest was associated with increased odds of survival in the congenital heart disease medical group (p = 0.03). Noncongenital heart disease medical patients experienced pulseless ventricular tachycardia/ventricular fibrillation more frequently than congenital heart disease medical patients (p = 0.02). Congenital heart disease medical patients had trends toward longer cardiac arrest durations, higher prevalence of neurologic sequelae postcardiopulmonary arrest, and higher mortality when extracorporeal support at cardiopulmonary resuscitation was employed.

CONCLUSIONS

Although trends in first documented rhythm, neurologic sequelae, and inotropic support prior to cardiopulmonary arrest were noted between groups, no significant differences in survival after cardiac arrest were seen. Larger scale studies are needed to better describe factors associated with cardiopulmonary arrest as well as survival in heterogeneous medical cardiac populations.