Background-We compared the therapeutic potential of purified mobilized human CD34ϩ cells with that of mobilized total mononuclear cells (tMNCs) for the preservation/recovery of myocardial tissue integrity and function after myocardial infarction (MI). Methods and Results-CD34ϩ cells were purified from peripheral blood tMNCs of healthy volunteers by magnetic cell sorting after a 5-day administration of granulocyte colony-stimulating factor. Phosphate-buffered saline (PBS), 5ϫ10 5 CD34

Background-A growing population of patients with coronary artery disease experiences angina that is not amenable to revascularization and is refractory to medical therapy. Preclinical studies have indicated that human CD34 ϩ stem cells induce neovascularization in ischemic myocardium, which enhances perfusion and function. Methods and Results-Twenty-four patients (19 men and 5 women aged 48 to 84 years) with Canadian Cardiovascular Society class 3 or 4 angina who were undergoing optimal medical treatment and who were not candidates for mechanical revascularization were enrolled in a double-blind, randomized (3:1), placebo-controlled dose-escalating study. Patients received granulocyte colony-stimulating factor 5 g · kg Ϫ1 · d Ϫ1 for 5 days with leukapheresis on the fifth day. Selection of CD34ϩ cells was performed with a Food and Drug Administration-approved device. Electromechanical mapping was performed to identify ischemic but viable regions of myocardium for injection of cells (versus saline). The total dose of cells was distributed in 10 intramyocardial, transendocardial injections. Patients were required to have an implantable cardioverterdefibrillator or to temporarily wear a LifeVest wearable defibrillator. No incidence was observed of myocardial infarction induced by mobilization or intramyocardial injection. The intramyocardial injection of cells or saline did not result in cardiac enzyme elevation, perforation, or pericardial effusion. No incidence of ventricular tachycardia or ventricular fibrillation occurred during the administration of granulocyte colony-stimulating factor or intramyocardial injections. One patient with a history of sudden cardiac death/ventricular tachycardia/ventricular fibrillation had catheter-induced ventricular tachycardia during mapping that required cardioversion. Serious adverse events were evenly distributed. Efficacy parameters including angina frequency, nitroglycerine usage, exercise time, and Canadian Cardiovascular Society class showed trends that favored CD34 ϩ cell-treated patients versus control subjects given placebo. Conclusions-A randomized trial of intramyocardial injection of autologous CD34ϩ cells in patients with intractable angina was completed that provides evidence for feasibility, safety, and bioactivity. A larger phase IIb study is currently under way to further evaluate this therapy. (Circulation. 2007;115:3165-3172.)

Background Multicenter longitudinal objective data for Fontan patients surviving into adulthood are lacking. Objectives Describe transplant-free survival and explore relationships between laboratory measures of ventricular performance and functional status over time. Methods Exercise testing, echocardiography, B-type natriuretic peptide (BNP), functional health assessment, and medical history abstraction were repeated 9.4 ± 0.4 years after the Fontan Cross-Sectional Study (Fontan 1) compared to previous values. Cox regression analysis explored risk factors for interim death or cardiac transplantation. Results From the original cohort of 546 subjects, 466 were recontacted and 373 (80%) were enrolled at 21.2 ± 3.5 years of age. Among subjects with paired testing, percent predicted maximum VO2 decreased (69 ± 14 vs. 61 ± 16, p <0.001, n = 95), ejection fraction decreased (58 ± 11 vs. 55 ± 10, p <0.001, n=259), and BNP increased (Median (IQR) 13 (7,25) vs. 18 (9,36) pg/mol, p <0.001, n = 340). At latest follow-up lower Pediatric Quality of Life Inventory (PedsQL) physical summary score was associated with poorer exercise performance (R2 adjusted = 0.20, p <0.001, n = 274). Cumulative complications since the Fontan included additional cardiac surgery (32%), catheter intervention (62%), arrhythmia treatment (32%), thrombosis (12%), and protein losing enteropathy (8%). Since Fontan 1, 54 subjects (10%) have received a heart transplant (n = 23) or died without transplantation (n = 31). The interval risk of death/transplantation was associated with poorer ventricular performance and functional health status assessed at Fontan 1, but was not associated with ventricular morphology, subject age or type of Fontan connection. Conclusions Interim transplant-free survival over 12 years in this Fontan cohort was 90% and was independent of ventricular morphology. Exercise performance decreased and was associated with worse functional health status. Future interventions might focus on preserving exercise capacity. (Clinical Trials Registration #: NCT00132782)

Objectives To describe growth patterns in infants with single ventricle physiology and determine factors influencing growth. Study design Data from 230 subjects enrolled in the Pediatric Heart Network Infant Single Ventricle Enalapril Trial were used to assess factors influencing change in weight-for-age z-score (Δz) from study enrollment (0.7 ± 0.4 months) to pre-superior cavopulmonary connection (SCPC) (5.1 ± 1.8 months, period 1), and pre-SCPC to final study visit (14.1 ± 0.9 months, period 2). Predictor variables included patient characteristics, feeding regimen, clinical center, and medical factors during neonatal (period 1) and SCPC hospitalizations (period 2). Univariate regression analysis was performed, followed by backward stepwise regression and bootstrapping reliability to inform a final multivariable model. Results Weights were available for 197/230 subjects for period 1 and 173/197 for period 2. For period 1, greater gestational age, younger age at study enrollment, tube feeding at neonatal discharge, and clinical center were associated with a greater negative Δz (poorer growth) in multivariable modeling (adjusted R2 = 0.39, p < 0.001). For period 2, younger age at SCPC and greater daily caloric intake were associated with greater positive Δz (better growth) (R2 = 0.10, p = 0.002). Conclusions Aggressive nutritional support and earlier SCPC are modifiable factors associated with a favorable change in weight-for-age z-score.

Background-Aging is a risk factor for coronary and peripheral artery disease. Tumor necrosis factor-␣ (TNF-␣), a proinflammatory cytokine, is expressed in ischemic tissue and is known to modulate angiogenesis. Little is known about the role of TNF-␣ receptors (TNFR1/p55 and TNFR2/p75) in angiogenic signaling. Methods and Results-We studied neovascularization in the hindlimb ischemia model in young and old TNFR2/p75 knockout (p75KO) and wild-type age-matched controls. Between days 7 to 10 after hindlimb surgery, 100% of old p75KOs experienced autoamputation of the operated limbs, whereas none of the age-matched wild-type mice exhibited hindlimb necrosis. Poor blood flow recovery in p75KO mice was associated with increased endothelial cell apoptosis, decreased capillary density, and significant reductions in the expression of vascular endothelial growth factor and basic fibroblast growth factor-2 mRNA transcripts in ischemic tissue and in circulating endothelial progenitor cells. The number of circulating bone marrow-derived endothelial progenitor cells was significantly reduced in p75KO mice. Transplantation of wild-type bone marrow mononuclear cells into irradiated old p75KO mice 1 month before hindlimb surgery prevented limb loss. Conclusions-Our present study suggests that ischemia-induced endothelial progenitor cell-mediated neovascularization is dependent, at least in part, on p75 TNF receptor expressed in bone marrow-derived cells. Specifically, endothelial cell/endothelial progenitor cell survival, vascular endothelial growth factor expression, endothelial progenitor cell mobilization from bone marrow, endothelial progenitor cell differentiation, and ultimately ischemia-induced collateral vessel development are dependent on signaling through TNFR2/p75. Furthermore, because TNFR2/p75 becomes an age-related limiting factor in postischemic recovery, it may be a potential gene target for therapeutic interventions in adult vascular diseases. (Circulation. 2007;115:752-762.)

Objectives To describe neurodevelopmental outcomes in infants with single ventricle (SV) physiology and determine factors associated with worse outcomes. Study design Neurodevelopmental outcomes for infants with SV enrolled in a multicenter drug trial were assessed at 14 months of age using the Bayley Scales of Infant Development-II. Multivariable regression analysis was used to identify factors associated with worse outcomes. Results Neurodevelopmental testing was performed at 14±1 months in 170/185 subjects in the trial. Hypoplastic left heart syndrome was present in 59% and 75% had undergone the Norwood operation. Mean psychomotor (PDI) and mental developmental indices (MDI) were 80±18 and 96±14 respectively (normal 100±15, P<0.001 for each). Group-based trajectory analysis provided a two-group model (high” and “low”) for height z-score trajectory and brain type natriuretic peptide (BNP) trajectory. The predicted PDI scores were 15 points higher in the “high” height z-score trajectory compared with the “low” cluster (P<.001). A higher number of serious adverse events during the trial was associated with lower PDI scores (P=.02). The predicted MDI scores were 13–17 points lower in “low height trajectory- high BNP trajectory” group compared with the other three groups (P<.001). MDI scores were also lower in subjects who required extracorporeal membrane oxygenation during the neonatal hospitalization (P=.01) or supplemental oxygen at discharge (P=.01). Conclusions Neurodevelopmental outcome at 14 months of age is impaired in infants with SV physiology. Low height trajectory and high BNP trajectory were associated with worse neurodevelopmental outcomes. Efforts to improve nutritional status alone may not improve neurodevelopmental outcomes.

Background Angiotensin converting enzyme (ACE) inhibitor therapy improves clinical outcome and ventricular function in adults with heart failure. Infants with single ventricle physiology have poor growth and are at risk for abnormalities in ventricular systolic and diastolic function. The ability of ACE inhibitor therapy to preserve ventricular function and improve somatic growth and outcomes in these infants is unknown. Methods and Results The Pediatric Heart Network conducted a double-blind trial involving 230 infants with single ventricle physiology randomized to receive enalapril (target dose 0.4 mg/kg/day) or placebo and followed to 14 months of age. The primary endpoint was weight-for-age z-score at 14 months. The primary analysis was intention-to-treat. A total of 185 infants completed the study. There were 24 and 21 withdrawals/deaths in the enalapril and placebo groups, respectively (P=0.74). Weight-for-age z-score was not different between the enalapril and placebo groups (mean±standard error, −0.62±0.13 vs. −0.42 ±0.13, P=0.28). There were no significant group differences in height-for-age z-score, Ross heart failure class, brain natriuretic peptide concentration, Bayley scores of infant development, or ventricular ejection fraction. The incidence of death or transplantation was 13% and did not differ between groups. Serious adverse events occurred in 88 patients in the enalapril group and 87 patients in the placebo group. Conclusions Administration of enalapril to infants with single ventricle physiology in the first year of life did not improve somatic growth, ventricular function, or heart failure severity. The results of this randomized trial do not support the routine use of enalapril in this population. Clinical Trials Registration Information ClinicalTrials.gov NCT00113087 http://www.clinicaltrials.gov/ct2/show/NCT00113087?term=enalapril+and+single+ventricle&rank=1

Objectives To assess variation in feeding practice at Norwood discharge, factors associated with tube feeding, and associations between site, feeding mode, and growth prior to stage II. Study design From May 2005 to July 2008, 555 subjects from 15 centers were enrolled in the Pediatric Heart Network Single Ventricle Reconstruction Trial; 432 survivors with Norwood discharge feeding data were analyzed. Results Demographic and clinical variables were compared among 4 feeding modes: oral only (n=140), oral/tube (n=195), nasogastric tube (N-tube) only (n=40), and gastrostomy tube (G-tube) only (n=57). There was significant variation in feeding mode among sites (oral only 0–81% and G-tube only 0–56%, p<0.01). After adjusting for site, multivariable modeling showed G-tube feeding at discharge was associated with longer hospitalization, and N-tube feeding was associated with greater number of discharge medications (R2=0.65, p<0.01). After adjusting for site, mean pre-stage II weight-for-age z-score (WAZ) was significantly higher in the oral only group (−1.4) vs. the N-tube only (−2.2) and G-tube only (−2.1) groups (p=0.04 and 0.02, respectively). Conclusions Feeding mode at Norwood discharge varied among sites. Prolonged hospitalization and greater number of medications at the time of Norwood discharge were associated with tube feeding. Infants exclusively fed orally had a higher WAZ pre-stage II than those fed exclusively by tube. Exploring strategies to prevent morbidities and promote oral feeding in this highest risk population is warranted.