Victor Bautista-Hernandez

Impaired Mitochondrial Biogenesis Precedes Heart Failure in Right Ventricular Hypertrophy in Congenital Heart Disease

Background— The outcome of the surgical repair in congenital heart disease correlates with the degree of myocardial damage. In this study, we determined whether mitochondrial DNA depletion is a sensitive marker of right ventricular (RV) damage and whether impaired mitochondrial DNA (mtDNA) replication contributes to the transition from compensated hypertrophy to failure. Methods and Results— RV samples obtained from 31 patients undergoing cardiac surgery were compared with 5 RV samples from nonfailing hearts (control). Patients were divided into compensated hypertrophy and failure groups, based on preoperative echocardiography, catheterization, and/or MRI data. Mitochondrial enzyme activities (citrate synthase and succinate dehydrogenase) were maintained during hypertrophy and decreased by ≈40% (P<0.05 versus control) at the stage of failure. In contrast, mtDNA content was progressively decreased in the hypertrophied RV through failure (by 28±8% and 67±11%, respectively, P<0.05 for both), whereas mtDNA-encoded gene expression was sustained by increased transcriptional activity during compensated hypertrophy but not in failure. Mitochondrial DNA depletion was attributed to reduced mtDNA replication in both hypertrophied and failing RV, and it was independent of PGC-1 downregulation but was accompanied by reduced expression of proteins constituting the mtDNA replication fork. Decreased mtDNA content in compensated hypertrophy was also associated with pathological changes of mitochondria ultrastructure. Conclusions— Impaired mtDNA replication causes early and progressive depletion of mtDNA in the RV of the patients with congenital heart disease during the transition from hypertrophy to failure. Decreased mtDNA content probably is a sensitive marker of mitochondrial injury in this patient population.

Long-term results of right ventricular outflow tract reconstruction in neonatal cardiac surgery: Options and outcomes

OBJECTIVES Neonatal surgery for tetralogy of Fallot and truncus arteriosus requires reconstruction of the right ventricular outflow tract. Although the method of reconstruction is often dictated by the individual anatomy, choices exist. This review examines the durability and outcomes of right ventricular outflow tract reconstruction in the neonate. METHODS This is a retrospective review of all 278 neonates with the diagnosis of tetralogy of Fallot and truncus arteriosus undergoing right ventricular outflow tract reconstruction at a single center between 1990 and 2007. Diagnostic variants included tetralogy of Fallot/pulmonary stenosis (n = 83), tetralogy of Fallot/pulmonary atresia (n = 81), and tetralogy of Fallot with absent pulmonary valve (n = 17). Truncus arteriosus was present in 97 patients. Patients were analyzed on the basis of diagnosis and the method of right ventricular outflow tract reconstruction: aortic homograft, pulmonary homograft, transannular patch, transannular patch with monocusp pulmonary valve, and nontransannular patch. Freedom from reoperation/reintervention was determined by using the log-rank test. RESULTS The mean age at right ventricular outflow tract reconstruction was 11.8 +/- 8 days, and hospital survival was 95.0% for the tetralogy of Fallot group and 90.7% for the truncus arteriosus group. Overall freedom from reoperation and reintervention was 76.2% +/- 14.8% in the nontransannular patch group and 59.5% +/- 6.8% in the transannular patch group; both were significantly greater than seen in patients receiving either aortic (0%) or pulmonary (6.7% +/- 4.2%) homografts (P < .05). There was no difference between aortic and pulmonary homografts. Among patients with tetralogy of Fallot/pulmonary stenosis, there was no difference in 10-year freedom from reoperation/reintervention between the transannular (70.8% +/- 7.4%) and nontransannular patch methods (76.2% +/- 14.8%, P = .53). At 10 years, the diagnosis of tetralogy of Fallot/pulmonary stenosis was associated with a greater freedom from reoperation/reintervention (68% +/- 6.8%) when compared with tetralogy of Fallot/pulmonary atresia (5.3% +/- 4.3%, P = .0001), tetralogy of Fallot/absent pulmonary valve (0%, P = .00315), or truncus arteriosus (4.2% +/- 2.8%, P = .0001). Eight patients (4 with tetralogy of Fallot/pulmonary stenosis, 3 with tetralogy of Fallot/pulmonary atresia, and 1 with tetralogy of Fallot/absent valve) underwent placement of a transannular patch with monocusp valve. Among this group, freedom from reoperation/reintervention is 41.7% +/- 20.5% at 2.5 years. Monocusp function, as determined by means of echocardiographic analysis obtained at 11.4 +/- 11.7 months (range, 0.3-31 months) showed an average monocusp gradient of 23.5 +/- 26.1 mm Hg, and 3 (37.5%) patients had more than moderate pulmonary regurgitation. CONCLUSIONS The durability of neonatal right ventricular outflow tract reconstruction is diagnosis and method dependent. Anatomy allowing right ventricular outflow tract patching (either transannular or nontransannular) provides a durability advantage compared with that seen with a homograft. There was no difference in performance between aortic and pulmonary homografts, and the monocusp valve has limited durability and effectiveness in neonatal right ventricular outflow tract surgery. The long-term outcomes of transannular and nontransannular patching techniques for neonatal repair of tetralogy of Fallot/pulmonary stenosis are similar.

Endovascular repair of concomitant celiac trunk and abdominal aortic aneurysms in a patient with Behçet's disease.

Purpose: To report endovascular repair of dual aneurysms in a patient with Behçets disease. Case Report: A 37-year-old man diagnosed 6 months prior with Behçets disease presented with a pulsating abdominal mass. Computed tomography revealed a 70-mm-diameter pseudoaneurysm in the abdominal aorta and another (20 mm) in the celiac trunk 5 mm from the aorta. Staged endovascular repair began with the aortic aneurysm, which was excluded with a bifurcated 23×140-mm Excluder stent-graft. Three days later, 2 Jostent stent-grafts were placed in the celiac trunk, successfully excluding the lesion. Fifteen days later, the patient was discharged on a regimen of clopidogrel, cyclosporine, and warfarin. At 6 months, the CT scan showed good perfusion of the stent-grafts. Conclusions: Aneurysmal involvement of the celiac trunk in a patient with Behçets disease is a rare pathology that appears amenable to stent-graft repair.

Impact of Age and Duration of Banding on Left Ventricular Preparation Before Anatomic Repair for Congenitally Corrected Transposition of the Great Arteries

BACKGROUND The optimal age and duration of left ventricular (LV) training in congenitally corrected transposition (ccTGA) with an unprepared LV is unknown. The objective of this study was to review the effect of age at pulmonary artery banding (PAB) and duration of ventricular training on LV function and aortic regurgitation (AR) after anatomic repair. METHODS The medical records of all patients who underwent PA banding for LV training between 1998 and 2011 were retrospectively reviewed. The primary end points were moderate or more LV dysfunction and moderate or more AR after anatomic repair. RESULTS During the study period, 25 patients with ccTGA underwent PAB for LV preparation. There was 1 early death. Eighteen patients underwent anatomic repair at a median of 10 months (range, 2 weeks to 11 years) from PAB. At the most recent follow-up after anatomic repair, moderate AR developed in 1 patient, and moderate or more LV dysfunction developed in 4. LV dysfunction developed in 4 of 6 patients banded after 2 years of age, compared with 0 of 12 patients banded before 2 years (p = 0.005). After anatomic repair, LV dysfunction developed in 4 of 7 patients repaired after age 3 years compared with 0 of 11 repaired before 3 years (p = 0.01). CONCLUSIONS Early PAB strategy is associated with favorable LV and neoaortic valve function after anatomic repair for ccTGA with an unprepared LV. Candidates for anatomic repair who require LV training should be referred early in infancy for consideration of appropriate timing of PAB.

Outcomes of transcatheter approach for initial treatment of pulmonary atresia with intact ventricular septum

To review the short and medium term outcome of transcatheter pulmonary valve perforation (PVP) in patients with pulmonary atresia‐intact ventricular septum and non‐right ventricular dependant coronary circulation (PA/IVS non‐RVDCC).

Preoperative Extracorporeal Membrane Oxygenation as a Bridge to Cardiac Surgery in Children With Congenital Heart Disease

BACKGROUND The efficacy of extracorporeal membrane oxygenation (ECMO) in bridging children with unrepaired heart defects to a definitive or palliative surgical procedure has been rarely reported. The goal of this study is to report our institutional experience with ECMO used to provide preoperative stabilization after acute cardiac or respiratory failure in patients with congenital heart disease before cardiac surgery. METHODS A retrospective review of the ECMO database at Childrens Hospital Boston was undertaken. Children with unrepaired congenital heart disease supported with ECMO for acute cardiac or respiratory failure as bridge to a definitive or palliative cardiac surgical procedure were identified. Data collection included patient demographics, indication for ECMO, details regarding ECMO course and complications, and survival to hospital discharge. RESULTS Twenty-six patients (18 male, 8 female) with congenital heart disease were bridged to surgical palliation or anatomic repair with ECMO. Median age and weight at ECMO cannulation were, respectively, 0.12 months (range, 0 to 193) and 4 kg (range, 1.8 to 67 kg). Sixteen patients (62%) survived to hospital discharge. Variables associated with mortality included inability to decannulate from ECMO after surgery (p = 0.02) and longer total duration of ECMO (p = 0.02). No difference in outcomes was found between patients with single and biventricular anatomy. CONCLUSIONS Extracorporeal membrane oxygenation, used as a bridge to surgery, represents a useful modality to rescue patients with failing circulation and unrepaired complex heart defects.

Surgical repair of truncal valve regurgitation

OBJECTIVES Truncal valve regurgitation remains a short- and long-term risk factor for patients with truncus arteriosus. There are limited data available on techniques and outcomes of truncal valve repair (TVR). The aim of this study was to report our experience with TVR in patients of all ages. METHODS From 1997 to 2012, 36 patients (13 neonates, 30 children and 3 adults) underwent TVR for significant regurgitation. RESULTS There were 3 early deaths (8%), all of which were in neonates. Twenty-two patients had a quadricuspid, 13 a tricuspid and 1 a bicuspid truncal valve before repair. Valve repair improved regurgitation in 31 of 36 repairs. The median regurgitation decreased from moderate-severe to mild (P < 0.001). During a mean follow-up of 38.3 ± 44.9 months (range 1 month-15 years), there was 1 late death, 16 patients required reoperation on the truncal valve and 1 required a second reoperation. Freedom from reoperation was 91.4 ± 4.8% at 1 year, 55.0 ± 10.4% at 5 and 22.9 ± 12.2% at 10 years. A quadricuspid valve after repair tended to worsen freedom from reoperation (P = 0.15), and tricuspidization tended to improve freedom from reoperation (P = 0.19). Neonatal repair (hazards ratio (HR) 4.1, P = 0.03) and leaflet thinning (HR 22.5, P = 0.002) were independent predictors of reoperation. CONCLUSIONS Valve repair for truncal valve regurgitation is feasible, with good results. Surgical creation of a tricuspid truncal valve seems to provide the best outcomes in this challenging population.

Impact of pacing on systemic ventricular function in L-transposition of the great arteries

OBJECTIVE(S) To assess the impact of univentricular versus biventricular pacing (BiVP) on systemic ventricular function in patients with congenitally corrected transposition of the great arteries (ccTGA). METHODS We performed a retrospective review of all patients with a diagnosis of ccTGA who underwent pacemaker insertion. From 1993 to 2014, 53 patients were identified from the cardiology database and surgical records. RESULTS Overall mortality was 7.5% (n = 4). One patient required transplantation and 3 late deaths occurred secondary to end-stage heart failure. Median follow-up was 3.7 years (range, 4 days to 22.5 years). Twenty-five (47%) underwent univentricular pacing only, of these, 8 (32%) developed significant systemic ventricular dysfunction. Twenty-eight (53%) received BiVP, 17 (26%) were upgraded from a dual-chamber system, 11 (21%) received primary BiVP. Fourteen (82%) of the 17 undergoing secondary BiVP demonstrated systemic ventricular dysfunction at the time of pacer upgrade, with 7 (50%) demonstrating improved systemic ventricular function after pacemaker upgrade. Overall, 42 (79%) patients underwent univentricular pacing, with 22 (52%) developing significant systemic ventricular dysfunction. In contrast, the 11 (21%) who received primary BiVP had preserved systemic ventricular function at latest follow-up. CONCLUSIONS Late-onset systemic ventricular dysfunction is a major complication associated with the use of univentricular pacing in patients with ccTGA. All patients with ccTGA who develop heart block should undergo primary biventricular pacing, as this prevents late systemic ventricular dysfunction. Preemptive placement of BiVP leads at the time of anatomical repair or other permanent palliative procedure will facilitate subsequent BiVP should heart block develop.

Mechanisms of tricuspid regurgitation in patients with hypoplastic left heart syndrome undergoing tricuspid valvuloplasty

OBJECTIVES Tricuspid regurgitation (TR) remains a risk factor for morbidity and mortality through staged palliation in patients with hypoplastic left heart syndrome (HLHS). Reports on the mechanisms associated with TR in patients with HLHS are limited. Thus, we sought to describe our experience with tricuspid valve (TV) repair in these patients, focusing on the mechanisms of TR and corresponding surgical techniques. METHODS We performed a retrospective single-center review (January 2000 to December 2012) of patients with HLHS undergoing TV repair and completing Fontan circulation. We evaluated the pre- and postoperative echocardiograms, intraoperative findings, and surgical techniques used. RESULTS A total of 53 TV repairs were performed in 35 patients with HLHS completing staged palliation. TV repairs were performed at stage II in 15, between stage II and III in 4, at stage III in 27, and after stage III in 7. The surgical techniques for valvuloplasty included annuloplasty (38%), anteroseptal (AS) commissuroplasty (66%), anterior papillary muscle repositioning (11%), multiple commissuroplasties (9%), septal-posterior commissuroplasty (9%), and fenestration closure (4%). The predominant jet of TR emanated along the AS commissure in 68% of the cases. All patients survived the procedure and were discharged. Preoperative echocardiography showed a dilated TV annulus on the lateral dimension, anteroposterior dimension, and area that was significantly reduced after TV repair (P < .0001). The preoperative mean TR, as assessed by lateral (P = .002) and anteroposterior (P = .005) vena contracta, was also significantly reduced after TV repair. TV repair did not significantly affect right ventricular systolic function immediately after surgery (P = .17) or at the most recent follow-up visit (P = .52). Patients with anterior leaflet prolapse were at increased risk of worse outcomes, including moderate or greater right ventricular dysfunction (P = .02). Patients requiring reoperation for TV repair were younger (6.3 vs 28.1 months, P < .0001) at the initial operation. One patient died of heart failure. Freedom from TV replacement and transplant-free survival were both 97% at the most recent follow-up point. CONCLUSIONS TR in patients with HLHS commonly emanates from the AS commissure. The associated mechanisms are often annular dilatation and anterior leaflet prolapse. Preoperative anterior leaflet prolapse was associated with worse outcomes. Annuloplasty, closure of the AS commissure, and repositioning of the anterior papillary muscle are effective in addressing TR in the short- and mid-term in this challenging population.

Atrioventricular valve annular remodeling with a bioabsorbable ring in young children.

To the Editor: Atrioventricular (AV) valve repair for regurgitation has been shown to be preferable to valve replacement in young children ([1][1]). Besides valvuloplasty technique, annulus reduction and stabilization with a ring have been demonstrated to be necessary to maintain effective leaflet