Serial assessment of postoperative ventricular mechanics in young children with tetralogy of Fallot: Comparison of transannular patch and valve-sparing repair

Comparing clinical and echocardiographic outcomes following valve-sparing versus transannular patch repair of tetralogy of Fallot: a systematic review and meta-analysis

OBJECTIVES

Transannular patch (TAP) repair of tetralogy of Fallot (ToF)relieves right ventricular tract obstruction but may lead to pulmonary regurgitation. Valve-sparing (VS) procedures can avoid this situation, but there is a potential for residual pulmonary stenosis. Our goal was to evaluate clinical and echocardiographic outcomes of TAP and VS repair for ToF.

METHODS

A systematic search of the PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials and Web of Science databases was carried out to identify articles comparing conventional TAP repair and VS repair for ToF. Random-effects models were used to perform meta-analyses of the clinical and echocardiographic outcomes.

RESULTS

Forty studies were included in this meta-analysis with data on 11 723 participants (TAP: 6171; VS: 5045). Participants who underwent a VS procedure experienced a significantly lower cardiopulmonary bypass time [mean difference (MD): -14.97; 95% confidence interval (CI): -22.54, -7.41], shorter ventilation duration (MD: -15.33; 95% CI: -30.20, -0.46) and shorter lengths of both intensive care unit (ICU) (MD: -0.67; 95% CI: -1.29, -0.06) and hospital stays (MD: -2.30; 95% CI: [-4.08, -0.52). There was also a lower risk of mortality [risk ratio: 0.40; 95% CI: (0.27, 0.60) and pulmonary regurgitation [risk ratio: 0.35; 95% CI: (0.26, 0.46)] associated with the VS group. Most other clinical and echocardiographic outcomes were comparable in the 2 groups.

CONCLUSIONS

This meta-analysis confirms the well-established increased risk of pulmonary insufficiency following TAP repair while also demonstrating that VS repairs are associated with several improved clinical outcomes. Continued research can identify the criteria for adopting a VS approach as opposed to a traditional TAP repair.

Right Ventricular and Outflow Tract Functional Characteristics After Repair of Tetralogy of Fallot with Major Aortopulmonary Collaterals

This study describes right ventricle (RV) characteristics and right ventricle to pulmonary artery (RV-PA) conduit function pre- and post-repair in patients with tetraology of Fallot with major aortopulmonary collaterals (TOF/MAPCAs). We reviewed patients who underwent single-stage, complete unifocalization, and repair of TOF/MAPCAs between 2006 and 2019 with available pre- and early postoperative echocardiograms. For a subset of patients, 6-12 month follow-up echocardiogram was available. RV and left ventricle (LV) characteristics and RV-PA conduit function were reviewed. Wilcoxon signed rank test and McNemar's test were used. 170 patients were reviewed, 46 had follow-up echocardiograms. Tricuspid valve annular plane systolic excursion (TAPSE) Z-scores were reduced from pre- (Z-score 0.01) to post-repair (Z-score -4.5, p < 0.001), improved but remained abnormal at follow-up (Z-score -4.0, p < 0.001). RV fractional area change (FAC) and LV ejection fraction were not significantly different before and after surgery. Conduit regurgitation was moderate or greater in 11% at discharge, increased to 65% at follow-up. RV-PA conduit failure (severe pulmonary stenosis or severe pulmonary regurgitation) was noted in 61, and 63% had dilated RV (diastolic RV area Z-score > 2) at follow-up. RV dilation correlated with the severe conduit regurgitation (p = 0.018). Longitudinal RV function was reduced after complete repair of TOF/MAPCAs, with decreased TAPSE and preserved FAC and LV ejection fraction. TAPSE improved but did not normalize at follow-up. Severe RV-PA conduit dysfunction was observed prior to discharge in 11% of patients and in 61% at follow-up. RV dilation was common at follow-up, especially in the presence of severe conduit regurgitation.

Right Ventricular Strain in Patients With Ductal-Dependent Tetralogy of Fallot

BACKGROUND

Right ventricular (RV) dysfunction is an independent predictor of poor outcomes in patients with tetralogy of Fallot (TOF), and global longitudinal strain (GLS) is a well-validated echocardiographic technique to measure RV function. Although trends in RV GLS have been examined in patients with TOF, they have not been studied specifically in those with ductal-dependent TOF, a group in which there is not a clear consensus on the best surgical strategy. The aim of this study was to assess the midterm trajectory of RV GLS in patients with ductal-dependent TOF, drivers of this trajectory, and differences in RV GLS between repair strategies.

METHODS

This was a retrospective two-center cohort study of patients with ductal-dependent TOF who underwent repair. Ductal dependence was defined as being initiated on prostaglandin therapy and/or undergoing surgical intervention on or before 30 days of life. RV GLS was measured on echocardiography preoperatively, early after complete repair, and at 1 and 2 years of age. RV GLS was trended over time and compared between surgical strategies and with control subjects. Mixed-effects linear regression models were used to evaluate the factors associated with changes in RV GLS over time.

RESULTS

Forty-four patients with ductal-dependent TOF were included in the study, of whom 33 (75%) underwent primary complete repair and 11 (25%) underwent staged repair. Complete TOF repair was performed at a median of 7 days in the primary-repair group and 178 days in the staged-repair group. RV GLS improved over time from post-complete repair echocardiography through 2 years of age (-17.4% [interquartile range, -15.5% to -18.9%] vs -21.5% [interquartile range, -18.0% to -23.3%], P < .001). However, compared with age-matched control subjects, patients had worse RV GLS at all time points. There was no difference in RV GLS between the staged and primary complete repair groups at 2-year follow-up. Shorter intensive care unit length of stay after complete repair was independently associated with improvement in RV GLS over time. Strain improved by 0.07% (95% CI, 0.01 to 0.12) for each fewer day in the intensive care unit (P = .03).

CONCLUSIONS

RV GLS improves over time among patients with ductal-dependent TOF, though it is consistently reduced compared with control subjects, suggesting an altered deformation pattern in patients with ductal-dependent TOF. There was no difference in RV GLS between the primary- and staged-repair groups at midterm follow-up, suggesting that repair strategy is not a risk factor for worse RV strain in the mid postoperative period. A shorter complete-repair intensive care unit length of stay is associated with an improved trajectory of RV GLS.

Predictive value of fetal echocardiographic parameters in surgical strategy for Tetralogy of Fallot

OBJECTIVES

This study aimed to evaluate whether fetal echocardiographic parameters were predictive of the postnatal surgical treatment required for fetuses with Tetralogy of Fallot (TOF).

METHODS

The fetal echocardiographic and postnatal clinical data of all cases of prenatal TOF at Xinhua Hospital from 2016 to 2020 were reviewed. Patients were categorized based on the operation type, and cardiac parameters were compared between groups.

RESULTS

Of the 37 fetuses assessed, the development of the pulmonary valve annulus (PVA) was significantly poorer in the transannular patch group. Patients with a prenatal PVA z-score (Schneider's method) ≥ -2.645, a PVA z-score (Lee's method) ≥ -2.805, a PVA/aortic valve annulus diameter ratio ≥ .697, and a pulmonary annulus index ≥ .823 were more likely to undergo pulmonary valve-sparing surgery. There was a strong correlation between prenatal and postnatal PVA z-scores. The PVA growth potential was greater in the pulmonary valve-sparing surgery group.

CONCLUSIONS

PVA-related parameters evaluated by fetal echocardiography can predict the type of surgical intervention required and are valuable in improving prenatal counseling in fetal cases of TOF.

Right Ventricular Strain Is Associated With Increased Length of Stay After Tetralogy of Fallot Repair

BACKGROUND

Little is known regarding right ventricular (RV) remodeling immediately after Tetralogy of Fallot (TOF) repair. We sought to describe myocardial deformation by cardiac magnetic resonance imaging (CMR) after TOF repair and investigate associations between these parameters and early post-operative outcomes.

METHODS

Fifteen infants underwent CMR without sedation as part of a prospective pilot study after undergoing complete TOF repair, prior to hospital discharge. RV deformation (strain) was measured using tissue tracking, in addition to RV ejection fraction (EF), volumes, and pulmonary regurgitant fraction. Pearson correlation coefficients were used to determine associations between both strain and CMR measures/clinical outcomes.

RESULTS

Most patients were male (11/15, 73%), with median age at TOF repair 53 days (interquartile range, 13,131). Most patients had pulmonary stenosis (vs. atresia) (11/15, 73%) and 7 (47%) received a transannular patch as part of their repair. RV function was overall preserved with mean RV EF of 62% (standard deviation [SD], 9.8). Peak radial and longitudinal strain were overall diminished (mean ± SD, 33.80 ± 18.30% and −15.50 ± 6.40%, respectively). Longer hospital length of stay after TOF repair was associated with worse RV peak radial ventricular strain (correlation coefficient (r), −0.54; p = 0.04). Greater pulmonary regurgitant fraction was associated with shorter time to peak radial RV strain (r = −0.55, p = 0.03).

CONCLUSIONS

In this small study, our findings suggest presence of early decrease in RV strain after TOF repair and its association with hospital stay when changes in EF and RV size are not yet apparent.

Right ventricular failure in congenital heart disease

PURPOSE OF REVIEW

We aim to review select literature pertaining to congenital heart disease (CHD)-induced right ventricular (RV) function and failure.

RECENT FINDINGS

We review recent findings pertaining to children and adults with repaired tetralogy of Fallot (rTOF), systemic RV and hypoplastic left heart syndrome (HLHS). We emphasize pathophysiological mechanisms contributing to RV dysfunction in these conditions, the risk factors for adverse outcomes and the continuing challenges in treating these patients. We discuss how recent pathology findings, as well as developments in imaging and computer modeling have broadened our understanding of the pathophysiology of these conditions. We further review developments in the molecular and cellular basis of RV failure; and in particular, the RV molecular response to stress in repaired tetralogy of Fallot (rTOF). We highlight some of the genetic complexities in HLHS and how these may influence the long-term outcomes in these patients.

SUMMARY

Recent literature has led to new understandings in the pathology, pathophysiology, risk factors for adverse outcomes, molecular and genetic basis for RV dysfunction and failure in CHD. Although these findings provide new therapeutic targets, the treatment of RV failure at this time remains limited.