David M. Peng

Impact of the 18th birthday on waitlist outcomes among young adults listed for heart transplant: A regression discontinuity analysis

BACKGROUNDnPatients listed for heart transplant after their 18th birthday purportedly wait longer to receive a donor heart compared with patients listed before their 18th birthday. It is unclear whether there is an actual difference in wait times and whether any difference in wait time is associated with lower likelihood of transplant and/or higher risk of mortality.nnnMETHODSnOrgan procurement and transplant network data were used to identify all patients listed for heart transplant between 2006 and 2014 within a 1-year period before and after their 18th birthday. The primary study end-point was the waiting time to receive a donor heart. Secondary end-points included the probability of transplant and waitlist mortality. Regression discontinuity analysis was used to analyze the effect of age on either side of the sharp cut-off value of age 18 years (6,574 days of life), when allocation of donor hearts transitions from the pediatric to adult allocation system.nnnRESULTSnA total of 360 patients met the study inclusion criteria, including 207 (57.5%) listed during the 12-month period before their 18th birthday under the pediatric allocation system, and 153 (42.5%) listed during the 12 months after their 18th birthday under the adult allocation system. The pediatric cohort was more likely to be listed Status 1A. Otherwise, the 2 groups shared similar baseline characteristics. Overall, patients listed after their 18th birthday waited 8.5 months longer to receive a transplant than adolescents listed before their 18th birthday (p = 0.01) and had a 47% lower probability of receiving a transplant (p = 0.001), but there was no difference in waitlist mortality (p = 0.37).nnnCONCLUSIONSnPatients listed for heart transplant shortly after their 18th birthday have significantly longer wait-times compared with patients listed shortly before their 18th birthday and a lower probability of transplant, but no significant difference in waitlist mortality. For medically fragile adolescents at high risk of death, birth date may be a relevant factor in the timing of heart transplant listing.

Impact of Heart Transplantation on the Functional Status of U.S. Children with End-Stage Heart Failure. Analysis of Data from the Organ Procurement and Transplantation Network.

Background —There are limited data describing the functional status (FS) of children after heart transplant (HT). We sought to describe the FS of children surviving at least one year after HT, to evaluate the impact of HT on FS, and to identify factors associated with abnormal FS post-HT. nnMethods —Organ Procurement and Transplantation Network data were used to identify all US children age <21 years surviving ≥1 year post-HT from 2005-2014 with a functional status score (FSS) available at three time points (listing, transplant, ≥1 year post-HT). Logistic regression and generalized estimating equations were used to identify factors associated with abnormal FS (FSS≤8) post-HT.nnResults —A total of 1,633 children met study criteria. At the 1-year assessment, 64% were fully active/no limitations (FSS=10), 21% had minor limitations with strenuous activity (FSS=9); 15% scored lower than 9. Compared to listing FS, FS at 1-year post-HT increased in 91% and declined/remained unchanged in 9%. A stepwise regression procedure selected the following variables for association with abnormal FS at 1-year post-HT: age ≥18 years (OR 1.8, 95% CI 1.2-2.7), African American race (OR 1.5, 95% CI 1.1-2.0), support with ≥inotropes at HT (OR 1.7, 95% CI 1.2-2.5), being hospitalized at HT (OR 1.5, 95% CI 1.0-2.19), chronic steroid use at HT (OR 1.5, 95% CI 1.0-2.2), and treatment for early rejection (OR 2.0, 95% CI 1.5-2.7). nnConclusions —Among US children who survive at least one year after HT, functional status is excellent for the majority of patients. HT is associated with substantial improvement in functional status for most children. Early rejection, older age, African American race, chronic steroid use, hemodynamic support at HT and being hospitalized at HT are associated with abnormal functional status post-HT.Background: There are limited data describing the functional status (FS) of children after heart transplant (HT). We sought to describe the FS of children surviving at least 1 year after HT, to evaluate the impact of HT on FS, and to identify factors associated with abnormal FS post-HT. Methods: Organ Procurement and Transplantation Network data were used to identify all US children <21 years of age surviving ≥1 year post-HT from 2005 to 2014 with a functional status score (FSS) available at 3 time points (listing, transplant, ≥1 year post-HT). Logistic regression and generalized estimating equations were used to identify factors associated with abnormal FS (FSS⩽8) post-HT. Results: A total of 1633 children met study criteria. At the 1-year assessment, 64% were “fully active/no limitations” (FSS=10), 21% had “minor limitations with strenuous activity” (FSS=9); and 15% scored ⩽8. In comparison with listing FS, FS at 1 year post-HT increased in 91% and declined/remained unchanged in 9%. A stepwise regression procedure selected the following variables for association with abnormal FS at 1 year post-HT: ≥18 years of age (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2–2.7), black race (OR, 1.5; 95% CI, 1.1–2.0), support with ≥inotropes at HT (OR, 1.7; 95% CI, 1.2–2.5), hospitalization status at HT (OR, 1.5; 95% CI, 1.0–2.19), chronic steroid use at HT (OR, 1.5; 95% CI, 1.0–2.2), and treatment for early rejection (OR, 2.0; 95% CI, 1.5–2.7). Conclusion: Among US children who survive at least 1 year after HT, FS is excellent for the majority of patients. HT is associated with substantial improvement in FS for most children. Early rejection, older age, black race, chronic steroid use, hemodynamic support at HT, and being hospitalized at HT are associated with abnormal FS post-HT.

Diagnosing neonatal aortic coarctation in the setting of patent ductus arteriosus

BACKGROUNDnIn neonates, it is challenging to diagnose aortic coarctation in the setting of a patent ductus arteriosus (PDA). Frequently, serial echocardiograms are performed, and diagnosis is delayed until the PDA closes. The purpose of this study was to identify echocardiographic predictors of neonatal coarctation in the presence of a PDA in cases in which diagnosis is uncertain.nnnMETHODSnWe retrospectively identified neonates diagnosed with possible but not definitive coarctation in the presence of a PDA by echocardiography (January 2004 through August 2013). The carotid-subclavian artery index (CSAi) was defined as the distal transverse arch diameter divided by the distance between the left common carotid and left subclavian arteries. Medical records were reviewed to identify patients who underwent coarctation repair within 1 year. A separate validation group was identified with the same methodology (September 2013 through April 2015).nnnRESULTSnThirty-three patients were identified (median age 1, range 0-8 days). Twelve patients (36%) underwent coarctation repair. The coarctation group had smaller aortic and mitral valves, distal transverse arch, and isthmus z scores, larger right innominate artery, and longer transverse arch compared with the remaining group (p < 0.05). The CSAi was lower in the coarctation group (p = 0.014), and a cutoff of less than 0.85 yielded a sensitivity of 0.83 and specificity of 0.86 for coarctation (area under the receiver operating characteristic curve, 0.91). In the validation group (n = 12; median follow-up, 316 days), none of the 8 patients with a CSAi of greater than 0.85 have required surgery. The intraclass correlation coefficient for CSAi was 0.79 (95% confidence interval, 0.18 to 0.95).nnnCONCLUSIONSnThe CSAi, a simple and reproducible measure, can identify neonates at risk for aortic coarctation even in the presence of a PDA, prevent multiple echocardiographic evaluations, and hence guide appropriate resource utilization.

Coronary Sinus Obstruction after Atrioventricular Canal Defect Repair

The coronary sinus can become obstructed with any instrumentation at or near the ostium such as in atrioventricular canal defect repairs. This complication may lead to a wide range of consequences including dyspnea, angina, myocardial infarction, and sudden death. The following report illustrates the importance of careful perioperative echocardiographic evaluation of the coronary sinus in procedures that may affect the sinus and its ostium.

Utility of screening echocardiogram after endomyocardial biopsy for identification of cardiac perforation or tricuspid valve injury

Per protocol, our institution obtains echocardiograms immediately after each EMB to rule out procedural complication. We sought to determine the incidence of echocardiogram‐detected cardiac perforation and TV injury and to evaluate the utility of routine screening echocardiogram after each EMB in the current era. At a single center, 99% (1917/1942) EMB performed in 162 patients were immediately followed by an echocardiogram per protocol. There were five newly diagnosed pericardial effusions, and only one required pericardiocentesis. In the three echocardiograms demonstrating new flail TV, only one patient underwent surgical repair 2 months later. This study demonstrates the very low incidence of significant hemopericardium and TV injury after EMB in pediatric heart transplant recipients and argues against the utility of post‐EMB echocardiograms to screen solely for procedural complications.

Pathological antibody-mediated rejection in pediatric heart transplant recipients: Immunologic risk factors, hemodynamic significance, and outcomes.

Biopsy‐diagnosed pAMR has been observed in over half of pediatric HT recipients within 6 years of transplantation. We report the incidence and outcomes of pAMR at our center. All endomyocardial biopsies for all HT recipients transplanted between 2010 and 2015 were reviewed and classified using contemporary ISHLT guidelines. Graft dysfunction was defined as a qualitative decrement in systolic function by echocardiogram or an increase of ≥3 mm Hg in atrial filling pressure by direct measurement. Among 96 patients, pAMR2 occurred in 7 (7%) over a median follow‐up period of 3.1 years, while no cases of pAMR3 occurred. A history of CHD, DSA at transplant, and elevated filling pressures were associated with pAMR2. Five‐sixths (83%) of patients developed new C1q+ DSA at the time of pAMR diagnosis. There was a trend toward reduced survival, with 43% of patients dying within 2.3 years of pAMR diagnosis.