Raheel Rizwan

Worldwide Experience with the Syncardia Total Artificial Heart in the Pediatric Population

Individual centers have documented the use of the Syncardia Total Artificial Heart (TAH) in adolescents with heart failure; however, the number of patients at any given center is small. Herein, we describe the worldwide experience for all patients ≤21 years old supported with the TAH between May 2005 and May 2015 (n = 43). The number of patients experiencing a positive outcome at 60, 90, and 120 days were 30 (70%), 27 (63%), and 25 (58%), respectively. Successful bridge to transplantation varied by diagnosis, but outcomes reported are similar to adults supported with the TAH or biventricular assist devices.

Changing demographics and outcomes of lung transplantation recipients with cystic fibrosis

BACKGROUND Cystic fibrosis (CF) is one of the most common diagnoses in adult and pediatric patients undergoing lung transplantation (LTx). A changing pattern of indications for LTx among patients with CF has been noted. This study analyzes the prevalence and characteristics of patients with CF who underwent LTx in the current era. METHODS A retrospective analysis was performed using data from the United Network of Organ Sharing database of all LTx performed from 1999 to 2013 (N = 20,345). Sub-analyses focused on children (<18 years old). Patients with CF who underwent LTx were assigned to early (1999-2003), mid (2004-2008), and current (2009-2013) eras based on the date of the procedure as well as before and after implementation of the new lung allocation score system in 2005. RESULTS CF was the indication for LTx in 14% (2,877) of who patients underwent LTx, a decrease from >17% in the early era to <13% in the current era (p < 0.001). In the pediatric cohort, CF was the indication for LTx in 383 (53%) patients, a proportion that also decreased across eras (early, 60%; mid, 53%; current, 47%; p = 0.009). The mean age of patients with CF undergoing LTx increased across the eras (early, 28 years ± 10; mid. 28 years ± 10; current, 30 years ± 11; p < 0.001). Pre-transplant ventilator use and incidence of pan-resistant infections also increased (p < 0.001), whereas pre-transplant forced expiratory volume in 1 second and waitlist times decreased (p < 0.001) in patients with CF. Graft survival across the eras remained similar (p > 0.05) at 5.1 years overall. CONCLUSIONS The proportion of LTx performed for CF has significantly decreased over time, a trend especially pronounced in pediatric patients. The change in pre-transplant characteristics across eras indicates a trend to perform LTx in more clinically ill and older patients with CF. The overall post-LTx survival has not changed.

Implications and outcomes of cardiac grafts refused by pediatric centers but transplanted by adult centers

Background According to Organ Procurement Transplant Network policy, hearts from donors age <18 years are offered to pediatric recipients before being offered to adults of the same health status. We aimed to analyze differences in the use of adolescent donor hearts between adult and pediatric candidates and also to analyze the outcomes of pediatric candidates in which an adolescent donor heart was refused and later used in an adult recipient. Methods All adolescent donors (age 12‐17 years) for 2000 to 2015 were identified using the standard United Network of Organ Sharing dataset and matched against the Potential Transplant Recipient dataset. Results Of the 2457 adults who received an adolescent heart, 855 (35%) received it after at least 1 refusal by a pediatric candidate (n = 844). Of the 844 pediatric candidates, 643 (76%) subsequently underwent transplantation (designated PCTs) and 201 (24%) never underwent transplantation (designated PCNTs). Among the latter group, 87 patients (43%) died or became too ill for transplantation. These 87 PCNTs refused 256 hearts that were later accepted by adult recipients. Donor quality was the most common reason for refusal. Overall, adult recipients had similar post‐transplantation survival compared with PCTs, all pediatric transplants, and all adult transplants (P > .10). A breakdown of adolescent heart donors by year shows a trend toward increased use in pediatric candidates. Conclusions A significant number of adolescent donor hearts that are refused by pediatric centers result in excellent post‐transplantation outcomes in adult recipients. One in 10 pediatric candidates died on the waitlist after refusal of these hearts used by adult recipients. This warrants careful evaluation of the refusal criteria used by pediatric centers. Encouragingly, there now appears to be a trend toward an increased use of adolescent donor hearts by pediatric centers.

Pediatric Heart Donor Assessment Tool (PH-DAT): A novel donor risk scoring system to predict 1-year mortality in pediatric heart transplantation

BACKGROUND In this study we sought to quantify hazards associated with various donor factors into a cumulative risk scoring system (the Pediatric Heart Donor Assessment Tool, or PH-DAT) to predict 1-year mortality after pediatric heart transplantation (PHT). METHODS PHT data with complete donor information (5,732) were randomly divided into a derivation cohort and a validation cohort (3:1). From the derivation cohort, donor-specific variables associated with 1-year mortality (exploratory p-value < 0.2) were incorporated into a multivariate logistic regression model. Scores were assigned to independent predictors (p < 0.05) based on relative odds ratios (ORs). RESULTS The final model had an acceptable predictive value (c-statistic = 0.62). The significant 5 variables (ischemic time, stroke as the cause of death, donor-to-recipient height ratio, donor left ventricular ejection fraction, glomerular filtration rate) were used for the scoring system. The validation cohort demonstrated a strong correlation between the observed and expected rates of 1-year mortality (r = 0.87). The risk of 1-year mortality increases by 11% (OR 1.11 [1.08 to 1.14]; p < 0.001) in the derivation cohort and 9% (OR 1.09 [1.04 to 1.14]; p = 0.001) in the validation cohort with an increase of 1-point in score. Mortality risk increased 5 times from the lowest to the highest donor score in this cohort. Based on this model, a donor score range of 10 to 28 predicted 1-year recipient mortality of 11% to 31%. CONCLUSION This novel pediatric-specific, donor risk scoring system appears capable of predicting post-transplant mortality. Although the PH-DAT may benefit organ allocation and assessment of recipient risk while controlling for donor risk, prospective validation of this model is warranted.

Modified Aortic Uncrossing Procedure: A Novel Approach for Norwood Palliation of Complex Univentricular Congenital Heart Disease With a Circumflex Aorta

The circumflex aorta is a rare type of true vascular ring anomaly. It consists of a retroesophageal right aortic arch, a left-sided descending thoracic aorta, and a left-sided ligamentum arteriosum. The “aortic uncrossing procedure” described by Planché and Lacour-Gayet is the procedure of choice for managing this aortic anomaly in patients with a biventricular heart. The presence of a circumflex aorta in a patient with heterotaxy syndrome and univentricular congenital heart disease requiring Norwood palliation is highly unusual. We report such a case and describe our approach to its surgical management.

Sequence of refusals for donor quality, organ utilization, and survival after lung transplantation

BACKGROUND Lung donor utilization rates remain low, with many organs refused for donor quality. However, some centers have successfully transplanted these organs despite multiple refusals for donor quality (RDQs) by other centers. We hypothesized that the number of refusals due to donor quality does not impact post-transplant outcomes. METHODS Lung transplants (LTxs) from 2006 to 2015, identified using the United Network for Organ Sharing (UNOS) database, were matched against the potential transplant recipient (PTR) data set by donor identification. Transplants were categorized into 2 groups: low RDQ (0 to 3 RDQs) and high RDQ (>3 RDQs). Post-transplant survival and predictors for high RDQ were observed using Kaplan‒Meier and logistic regression analyses, respectively. RESULTS Of 10,126 adult (>18 years) LTxs, 77% had at least 1 RDQ, with a median of 4 RDQs. Post-transplant 1-year survival was similar for both the low and high RDQ groups (p = 0.49). Furthermore, groups of recipients who received donors with an increasing number of RDQs (>3, >6, or >10) also had similar post-transplant 1-year survival (p = 0.77). Treatment for rejection within 1 year and intubation at 72 hours post-transplant were higher in the high RDQ group (p < 0.01). An inverse relationship was identified between the number of RDQs and likelihood of utilization. After 10 RDQs, the likelihood of utilization varied significantly by donor characteristics. CONCLUSIONS Lung transplant survival is not associated with number of refusals due to donor quality. When determining whether an organ is suitable for transplant, the number of refusals due to donor quality should not influence ones decision, especially in this era of limited donor supply.

Pediatric Heart Transplantation Long-Term Survival in Different Age and Diagnostic Groups: Analysis of a National Database

Background: The purpose of this study was to evaluate differences in long-term survival without the influence of early mortality, and to identify factors associated with one-year conditional ten-year survival after heart transplantation (HTx) across different age and diagnostic groups. Methods: Organ Procurement and Transplant Network data from January 1990 to December 2005 were used. Cohort was divided according to age (infants [<1 year], children [>1-10 years], and adolescents [11-18 years]) and diagnosis (cardiomyopathy and congenital heart disease [CHD]). Factors associated with one-year conditional ten-year survival were identified using multivariable logistic regression and using a case–control design. Results: One-year conditional ten-year survivors included 1,790 patients compared to 1,114 patients who died after the first posttransplant year and within ten years of transplant with a median follow-up of 4.8 years. Predictors of one-year conditional ten-year survival for infants were recipient’s Caucasian race (odds ratio [OR]: 1.9, 95% confidence interval [CI]: 1.3-2.7) and donor–recipient weight ratio (OR: 0.8, 95% CI: 0.6-1); for children: Caucasian race (OR: 1.6, 95% CI: 1.2-2.1), retransplantation (OR: 0.4, 95% CI: 0.2-0.6), and transplantation after the year 2000 (OR: 1.5, 95% CI: 1.1-2.1); for adolescents only Caucasian race (OR: 2.5, 95% CI: 1.9-2.3). In both CHD and cardiomyopathy, adolescents had worse survival compared to infants and children. There was an era effect with improved survival after 2000. Male gender was a predictor of survival in cardiomyopathy group. Conclusion: Predictors of one-year conditional ten-year survival varied among groups. These data and analyses provide important information that may be useful to clinicians, particularly when counseling patients and families regarding expectations of survival after pediatric HTx.