Eric J. Devaney

Prospective Trial of a Pediatric Ventricular Assist Device

BACKGROUND Options for mechanical circulatory support as a bridge to heart transplantation in children with severe heart failure are limited. METHODS We conducted a prospective, single-group trial of a ventricular assist device designed specifically for children as a bridge to heart transplantation. Patients 16 years of age or younger were divided into two cohorts according to body-surface area (cohort 1, <0.7 m(2); cohort 2, 0.7 to <1.5 m(2)), with 24 patients in each group. Survival in the two cohorts receiving mechanical support (with data censored at the time of transplantation or weaning from the device owing to recovery) was compared with survival in two propensity-score-matched historical control groups (one for each cohort) undergoing extracorporeal membrane oxygenation (ECMO). RESULTS For participants in cohort 1, the median survival time had not been reached at 174 days, whereas in the matched ECMO group, the median survival was 13 days (P<0.001 by the log-rank test). For participants in cohort 2 and the matched ECMO group, the median survival was 144 days and 10 days, respectively (P<0.001 by the log-rank test). Serious adverse events in cohort 1 and cohort 2 included major bleeding (in 42% and 50% of patients, respectively), infection (in 63% and 50%), and stroke (in 29% and 29%). CONCLUSIONS Our trial showed that survival rates were significantly higher with the ventricular assist device than with ECMO. Serious adverse events, including infection, stroke, and bleeding, occurred in a majority of study participants. (Funded by Berlin Heart and the Food and Drug Administration Office of Orphan Product Development; ClinicalTrials.gov number, NCT00583661.).

Berlin Heart EXCOR Pediatric Ventricular Assist Device for Bridge to Heart Transplantation in US Children

Background— Recent data suggest that the Berlin Heart EXCOR Pediatric ventricular assist device is superior to extracorporeal membrane oxygenation for bridge to heart transplantation. Published data are limited to 1 in 4 children who received the device as part of the US clinical trial. We analyzed outcomes for all US children who received the EXCOR to characterize device outcomes in an unselected cohort and to identify risk factors for mortality to facilitate patient selection. Methods and Results— This multicenter, prospective cohort study involved all children implanted with the Berlin Heart EXCOR Pediatric ventricular assist device at 47 centers from May 2007 through December 2010. Multiphase nonproportional hazards modeling was used to identify risk factors for early (<2 months) and late mortality. Of 204 children supported with the EXCOR, the median duration of support was 40 days (range, 1–435 days). Survival at 12 months was 75%, including 64% who reached transplantation, 6% who recovered, and 5% who were alive on the device. Multivariable analysis identified lower weight, biventricular assist device support, and elevated bilirubin as risk factors for early mortality and bilirubin extremes and renal dysfunction as risk factors for late mortality. Neurological dysfunction occurred in 29% and was the leading cause of death. Conclusions— Use of the Berlin Heart EXCOR has risen dramatically over the past decade. The EXCOR has emerged as a new treatment standard in the United States for pediatric bridge to transplantation. Three-quarters of children survived to transplantation or recovery; an important fraction experienced neurological dysfunction. Smaller patient size, renal dysfunction, hepatic dysfunction, and biventricular assist device use were associated with mortality, whereas extracorporeal membrane oxygenation before implantation and congenital heart disease were not.

Bridging children of all sizes to cardiac transplantation: The initial multicenter North American experience with the Berlin Heart EXCOR ventricular assist device

BACKGROUND Beginning in 2000 and accelerating in 2004, the Berlin Heart EXCOR (Berlin Heart Inc Woodlands, TX) became the first pediatric-specific ventricular assist device (VAD) applied throughout North America for children of all sizes. This retrospective study analyzed the initial Berlin Heart EXCOR pediatric experience as a bridge to transplantation. METHODS Between June 2000 and May 2007, 97 EXCOR VADs were implanted in North America at 29 different institutions. The analysis is limited to 73 patients (75%) from 17 institutions, for which retrospective data were available. RESULTS Median age and weight at VAD implant were 2.1 years (range, 12 days-17.8 years) and 11 kg (range, 3-87.6 kg), respectively. The primary diagnoses were dilated cardiomyopathy in 42 (58%), congenital heart disease in 19 (26%), myocarditis in 7 (10%), and other cardiomyopathies in 5 (7%). Pre-implant clinical condition was critical cardiogenic shock in 38 (52%), progressive decline in 33 (45%), or other in 2 (3%). Extracorporeal membrane oxygenation was used as a bridge to EXCOR in 22 patients (30%). Device selection was left VAD (LVAD) in 42 (57%) and biventricular assist devices (BiVAD) in 31 (43%). The EXCOR bridged 51 patients (70%) to transplant and 5 (7%) to recovery. Mortality on the EXCOR was 23% (n = 17) overall, including 35% (11 of 31) in BiVAD vs 14% (6 of 42) in LVAD patients (p = 0.003). Multivariate analysis showed younger age and BiVAD support were significant risk factors for death while on the EXCOR. CONCLUSIONS This limited but large preliminary North American experience with the Berlin Heart EXCOR VAD as a bridge to cardiac transplantation for children of all ages and sizes points to the feasibility of this approach. The prospective investigational device evaluation trial presently underway will further characterize the safety and efficacy of the EXCOR as a bridge to pediatric cardiac transplantation.

Esophagectomy for achalasia: patient selection and clinical experience

BACKGROUND In 1989, we predicted an increasing number of esophagectomies for megaesophagus and for recurrent symptoms after prior esophagomyotomy or balloon dilatation for achalasia. Patient selection in this group is challenging, as the potential operative morbidity of an esophagectomy must be weighed against the expected clinical outcome after a redo esophagomyotomy or alternative procedures designed to salvage the native esophagus. METHODS The hospital records of 93 patients undergoing esophagectomy for achalasia during the past 20 years were reviewed retrospectively and the results of operation assessed using our prospectively established Esophageal Resection Database and follow-up information obtained through personal contact with the patients. RESULTS Patient age averaged 51 years. Indications for esophagectomy included tortuous megaesophagus (64%), failure of prior myotomy (63%), and associated reflux stricture (7%). Ninety-four percent of the patients underwent a transhiatal esophagectomy. Stomach was used as the esophageal substitute in 91% cases. Intraoperative blood loss averaged 672 mL. Postoperative length of stay averaged 12.5 days. Major complications included anastomotic leak (10%), recurrent laryngeal nerve injury (5%), delayed mediastinal bleeding requiring thoracotomy (2%), and chylothorax (2%). There were 2 hospital deaths (2%) from respiratory insufficiency and sepsis. Follow-up has averaged 38 months. In all, 95% of patients eat well; nearly 50% have required an anastomotic dilatation; troublesome regurgitation has been rare; and 4% have refractory postvagotomy dumping. CONCLUSIONS Esophagectomy, preferably through a transhiatal approach, is generally safe and effective therapy in selected patients with achalasia. Unique technical considerations include difficulty encircling the dilated cervical esophagus, deviation of the esophagus into the right chest, large aortic esophageal arteries, and adherence of the exposed esophageal submucosa to the adjacent aorta after prior myotomy.

Fontan operation in the current era: a 15-year single institution experience.

Objective:Evaluate current risk factors for mortality and morbidity in patients undergoing the Fontan procedure at a single institution in the current era. Summary Background Data:An emphasis on early relief of volume and pressure overload culminating in the Fontan procedure has improved patient outcomes for patients with a single ventricle. Methods:A cross-sectional retrospective study was performed for 636 primary Fontan procedures between July 1992 and June 2007. Results:Anatomy included left ventricular hypoplasia in 64% and right ventricular hypoplasia in 36%. A lateral tunnel (LT) was performed in 92% and an extracardiac conduit (EC) in 8%. Hospital survival was 96%. Long-term survival was 97% at a mean follow-up of 50 months (range, 0–173 months). Ventricular anatomy and preoperative hemodynamics did not predict early or late survival. Longer aortic cross clamp (XC) time was associated with decreased late survival (P = 0.01). Fontan takedown was required in 3% and protein-losing enteropathy (PLE) developed in 6%. At follow-up, 98% of patients were either NYHA class I or II and 87% were in normal sinus rhythm. Patients with chest tube drainage >2 weeks had an increased risk of PLE (P < 0.0001) and diminished short- and long-term survival (P = 0.026 and P < 0.0001, respectively). Conclusions:The Fontan procedure can be performed with low risk regardless of ventricular anatomy. Duration of XC time is associated with survival. Prolonged CT drainage correlates with late PLE and diminished survival. There was a low prevalence of late rhythm disturbances and other complications.

A United Network for Organ Sharing analysis of heart transplantation in adults with congenital heart disease: Outcomes and factors associated with mortality and retransplantation

OBJECTIVES Heart transplantation in patients with adult congenital heart disease is increasing, yet no large studies have defined how this subgroup differs from other adult recipients. We investigated outcomes and risk factors for mortality and retransplantation among patients with adult congenital heart disease compared with adult recipients. METHODS A review was performed of 18- to 45-year-old patients undergoing heart transplantation from 1990-2008 reported to the United Network for Organ Sharing database. Trends were compared between 2 eras: era 1 (1990-1998) and era 2 (1999-2008). Multivariable semiparametric hazard models identified factors associated with time-related death and retransplantation. RESULTS Of 8496 patients identified, 575 had adult congenital heart disease. The prevalence of heart transplantation among adult recipients decreased by 28% over time (P < .001) and increased among patients with adult congenital heart disease by 41% (P < .001). Induction therapy use was less in patients with adult congenital heart disease (66%) compared with that seen in adult recipients (71%, P = .02). Steroid maintenance was less in patients with adult congenital heart disease (92%) compared with that seen in adult recipients (97%, P < .001). Post-heart transplantation survival among adult recipients improved over time (P = .02) but not among patients with adult congenital heart disease (P = .81). Overall post-heart transplantation mortality (P = .006) and retransplantation (P = .03) were significantly higher for patients with adult congenital heart disease than for adult recipients, mainly because of an early hazard phase. Adult congenital heart disease was a risk factor for both death (P < .001) and retransplantation (P = .04). Any induction therapy and steroid maintenance was associated with improved survival for all recipients (P = .001). CONCLUSIONS Adult congenital heart disease represent an increasing proportion of heart transplant recipients. Compared with adult recipients, patients with adult congenital heart disease experience higher post-heart transplantation mortality and retransplantation. Immunosuppression differs among patients with adult congenital heart disease and adult recipients. Further studies should investigate whether post-heart transplantation outcomes would be improved by more aggressive induction therapy or judicious steroid tapers.

Performance of CryoValve SG Decellularized Pulmonary Allografts Compared With Standard Cryopreserved Allografts

BACKGROUND There is no ideal option for pulmonary valve replacement in children. Cryopreserved pulmonary allografts frequently demonstrate early valve regurgitation and may elicit an immune response. To improve these shortcomings, the SynerGraft process (CryoLife, Kennesaw, GA) decellularizes an allograft, leaving only connective tissue, which then becomes repopulated with host cells. A previous study at our institution demonstrated superior short-term durability of the SynerGraft-processed CryoValve SG compared with standard allografts. Longer-term impact of the technology remains unknown. METHODS A single institution review was performed of all CryoValve SGs implanted between 2001 and 2004. Forty-one CryoValve SG patients and 41 age and diagnosis-matched standard allograft controls were evaluated. Demographics, survival, reintervention, and echocardiographic findings were analyzed. RESULTS There were no significant differences between groups in demographics, valve diameter, orthotopic-heterotopic allograft position, or follow-up. For the entire cohort, there was no difference in early or late insufficiency or stenosis at a mean follow-up of 46 +/- 14 months. However, freedom from moderate to severe insufficiency (>3+) was significantly better for CryoValve SG patients (p = 0.05). In addition, for patients greater than 2 years of age, CryoValve SGs were significantly less regurgitant (p = 0.045) and stenotic (p = 0.041). Long-term survival was identical at 85% (35 of 41). CONCLUSIONS When compared with standard allografts, CryoValve SGs demonstrate superior freedom from significant insufficiency at intermediate follow-up. In older children, CryoValve SGs display less insufficiency and stenosis. For infants, patient age, valve diameter, previous conduit, and rapid somatic growth would likely be the predominant factors leading to allograft failure.

Myosin light chain 2-based selection of human iPSC-derived early ventricular cardiac myocytes

Applications of human induced pluripotent stem cell derived-cardiac myocytes (hiPSC-CMs) would be strengthened by the ability to generate specific cardiac myocyte (CM) lineages. However, purification of lineage-specific hiPSC-CMs is limited by the lack of cell marking techniques. Here, we have developed an iPSC-CM marking system using recombinant adenoviral reporter constructs with atrial- or ventricular-specific myosin light chain-2 (MLC-2) promoters. MLC-2a and MLC-2v selected hiPSC-CMs were purified by fluorescence-activated cell sorting and their biochemical and electrophysiological phenotypes analyzed. We demonstrate that the phenotype of both populations remained stable in culture and they expressed the expected sarcomeric proteins, gap junction proteins and chamber-specific transcription factors. Compared to MLC-2a cells, MLC-2v selected CMs had larger action potential amplitudes and durations. In addition, by immunofluorescence, we showed that MLC-2 isoform expression can be used to enrich hiPSC-CM consistent with early atrial and ventricular myocyte lineages. However, only the ventricular myosin light chain-2 promoter was able to purify a highly homogeneous population of iPSC-CMs. Using this approach, it is now possible to develop ventricular-specific disease models using iPSC-CMs while atrial-specific iPSC-CM cultures may require additional chamber-specific markers.

Designing Heart Performance by Gene Transfer

The birth of molecular cardiology can be traced to the development and implementation of high-fidelity genetic approaches for manipulating the heart. Recombinant viral vector-based technology offers a highly effective approach to genetically engineer cardiac muscle in vitro and in vivo. This review highlights discoveries made in cardiac muscle physiology through the use of targeted viral-mediated genetic modification. Here the history of cardiac gene transfer technology and the strengths and limitations of viral and nonviral vectors for gene delivery are reviewed. A comprehensive account is given of the application of gene transfer technology for studying key cardiac muscle targets including Ca(2+) handling, the sarcomere, the cytoskeleton, and signaling molecules and their posttranslational modifications. The primary objective of this review is to provide a thorough analysis of gene transfer studies for understanding cardiac physiology in health and disease. By comparing results obtained from gene transfer with those obtained from transgenesis and biophysical and biochemical methodologies, this review provides a global view of cardiac structure-function with an eye towards future areas of research. The data presented here serve as a basis for discovery of new therapeutic targets for remediation of acquired and inherited cardiac diseases.

Early and Intermediate Outcome After Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries

BACKGROUND Anatomic repair of congenitally corrected transposition of the great arteries has become a useful surgical strategy with potential advantages over conventional surgical repair. We describe early and intermediate outcomes after anatomic repair and analyze potential risk factors influencing these outcomes. METHODS A retrospective review was performed on all patients undergoing anatomic repair between January 1993 and January 2009. The primary outcome was in-hospital mortality. Variables potentially associated with outcome were identified a priori. Bivariate analyses were performed to determine the association between these variables and all outcome measures. RESULTS In 65 patients who underwent anatomic repair, 35 had Senning/arterial switch and 30 had Senning/Rastelli. Early and intermediate survival rates for Senning/arterial switch operations were 94% and 91%, respectively. Repairs were successful in patients with tricuspid regurgitation, left ventricular outflow obstruction, and left ventricular dysfunction. Predictors of outcome were not identified in this subset. Early and intermediate survival rates for Senning/Rastelli operations were 77% and 60%, respectively. Longer aortic cross-clamp (p = 0.03) and cardiopulmonary bypass times (p = 0.01) were associated with mortality. Ventricular septal defect enlargement was associated with surgical heart block (p < 0.01). Age, prior procedures, atrial-apical discordance, and tricuspid regurgitation were not associated with outcome. CONCLUSIONS Senning/arterial switch operations can be performed with excellent intermediate-term outcomes in patients with lesions previously thought to confer higher risk. Candidates for Senning/Rastelli procedures may be at increased risk for postoperative morbidity and mortality. More data are necessary to determine factors influencing outcome after anatomic repair.