Tetralogy of Fallot in adults.

BACKGROUND: Following surgical repair in infancy, a high proportion of children born with tetralogy of Fallot are surviving into adulthood, and it is important that these patients are monitored by an adult congenital heart disease specialist for problems and complications that can occur in the adult patient. OBJECTIVE: To provide an overview on the management of adult patients with repaired tetralogy of Fallot and emphasise the need for specialist follow-up. DISCUSSION: Following surgical repair of tetralogy of Fallot, it is important to have lifelong surveillance in adulthood for complications such as pulmonary valve dysfunction. Modern imaging modalities have helped with monitoring and the early detection of problems. Cardiac surgery has been refined over the years, leading to improved longevity. Over the past 23 years, percutaneous interventions have been developed to deal with valve complications and the results have been promising. Healthy behaviour, such as regular exercise, and behaviours to minimise the risk of endocarditis should be encouraged. Regular follow-up with an adult congenital heart disease specialist is important. Patients wishing to undertake a pregnancy should be supervised through a high-risk pregnancy clinic.

Long-Term Effects of Pulmonary Valve Implantation and Prosthesis Evolution in Patients with Repaired Tetralogy of Fallot. / Efeitos de Longo Prazo do Implante Valvar Pulmonar e Evolução da Prótese em Pacientes com Tetralogia de Fallot Corrigida.

BACKGROUND: Pulmonary valve regurgitation is a significant long-term complication in patients with tetralogy of Fallot (TOF). OBJECTIVE: This study aims to investigate the effects of pulmonary valve implantation (PVI) on the anatomy and function of the right ventricle (RV) and the long-term evolution of the implanted prosthesis in the pulmonary position. METHODS: A single-center retrospective cohort analysis was performed in 56 consecutive patients with TOF who underwent PVI. The study included patients of both sexes, aged ≥ 12 years, and involved assessing clinical and surgical data, pre- and post-operative cardiovascular magnetic resonance imaging, and echocardiogram data more than 1 year after PVI. RESULTS: After PVI, there was a significant decrease in RV end-systolic volume indexed by body surface area (BSA), from 89 mL/BSA to 69 mL/BSA (p < 0.001) and indexed RV end-diastolic volume, from 157 mL/BSA to 116 mL/BSA (p < 0.001). Moreover, there was an increase in corrected RV ejection fraction [ RVEFC = net pulmonary flow (pulmonary forward flow - regurgitant flow) / R V end-diastolic volume ] from 23% to 35% (p < 0.001) and left ventricular ejection fraction from 58% to 60% (p = 0.008). However, a progressive increase in the peak pulmonary valve gradient was observed over time, with 25% of patients experiencing a gradient exceeding 60 mmHg. Smaller prostheses (sizes 19 to 23) were associated with a 4.3-fold higher risk of a gradient > 60 mmHg compared to larger prostheses (sizes 25 to 27; p = 0.029; confidence interval: 1.18 to 17.8). CONCLUSION: As expected, PVI demonstrated improvements in RV volumes and function. Long-term follow-up and surveillance are crucial for assessing the durability of the prosthesis and detecting potential complications. Proper sizing of prostheses is essential for improved prosthesis longevity.

Differences in Right Heart Function After Pulmonary Valve Replacement in Patients With Pulmonary Valve Stenosis Versus Tetralogy of Fallot.

BACKGROUND: There are limited data about the impact of timing of pulmonary valve replacement (PVR) on right heart reverse remodeling in patients with pulmonary regurgitation following intervention for isolated pulmonary valve stenosis (PS). This study compared differences in postprocedural right heart reverse remodeling after early versus late PVR (defined as PVR before versus after attainment of the conservative consensus criteria proposed by Bokma et al, 2018) in patients with prior intervention for PS, using patients with tetralogy of Fallot as the reference group. METHOD AND RESULTS: Right atrial reservoir strain and right ventricular free wall strain was measured at baseline, 1 and 3 years after PVR. There were 114 patients with PS (early PVR, 87 [76%]; late PVR, 27 [24%]) and 291 patients with tetralogy of Fallot (early PVR, 197 [67%]; late PVR, 96 [33%]). The PS group had greater improvement in right atrial reservoir strain at 1 year (12%±4% versus 8%±4%; P<0.001) and 3 years (15%±6% versus 9%±6%; P<0.001), and a greater improvement in right ventricular free wall strain at 1 year (12%±4% versus 7%±3%, P=0.008) and 3-years (16%±6% versus 12%±5%; P=0.01) after PVR compared with the tetralogy of Fallot group. There was no difference in right heart reverse remodeling between patients who underwent early versus later PVR within the PS group. In contrast, late PVR was associated with less right heart reverse remodeling within the tetralogy of Fallot group. CONCLUSIONS: These data suggest that patients with palliated PS presenting pulmonary regurgitation have a more benign clinical course, and hence delaying PVR in this population may be appropriate.

Molecular Pathways and Animal Models of Tetralogy of Fallot and Double Outlet Right Ventricle.

Tetralogy of Fallot and double-outlet right ventricle are outflow tract (OFT) alignment defects situated on a continuous disease spectrum. A myriad of upstream causes can impact on ventriculoarterial alignment that can be summarized as defects in either i) OFT elongation during looping morphogenesis or ii) OFT remodeling during cardiac septation. Embryological processes underlying these two developmental steps include deployment of second heart field cardiac progenitor cells, establishment and transmission of embryonic left/right information driving OFT rotation and OFT cushion and valve morphogenesis. The formation and remodeling of pulmonary trunk infundibular myocardium is a critical component of both steps. Defects in myocardial, endocardial, or neural crest cell lineages can result in alignment defects, reflecting the complex intercellular signaling events that coordinate arterial pole development. Importantly, however, OFT alignment is mechanistically distinct from neural crest-driven OFT septation, although neural crest cells impact indirectly on alignment through their role in modulating signaling during SHF development. As yet poorly understood nongenetic causes of alignment defects that impact the above processes include hemodynamic changes, maternal exposure to environmental teratogens, and stochastic events. The heterogeneity of causes converging on alignment defects characterizes the OFT as a hotspot of congenital heart defects.

Assessment of Pulmonary Arterial Vascular Impedance in Fetuses With Tetralogy of Fallot.

OBJECTIVE: To evaluate the vascular impedance of the pulmonary arteries in fetuses with tetralogy of Fallot (TOF) by Doppler echocardiography. METHODS: A total of 42 fetuses with TOF (TOF group) and 84 gestational age-matched normal fetuses (control group) were prospectively collected from the Second Xiangya Hospital of Central South University from August 2022 to January 2023. The severity of TOF was classified into mild TOF (z score ≥-2), moderate TOF (-4 < z score < -2), or severe TOF (z score ≤-4) according to the z score value of the pulmonary annulus diameter. The pulsatility index (PI) of the main pulmonary artery (MPA), distal left pulmonary artery (DLPA), and distal right pulmonary artery (DRPA) were measured by pulsed-wave Doppler. The differences in clinical data and echocardiographic parameters between TOF group, control group, and TOF subgroups were compared. RESULTS: Compared with the control group, MPA-PI increased significantly, whereas DLPA-PI and DRPA-PI decreased in TOF group (all P < .001). There were no significant differences in MPA-PI and DRPA-PI among mild TOF, moderate TOF, and severe TOF (all P > .05). However, DLPA-PI decreased significantly in severe TOF compared with mild TOF (P < .05). CONCLUSION: Fetuses with TOF presented increased vascular impedance in the pulmonary trunk and decreased impedance in distal pulmonary artery branches. Further large and follow-up studies are needed to demonstrate the associations between those changed vascular impedances and the development of PA in patients with TOF.

Transcatheter-Based Interventions for Tetralogy of Fallot Across All Age Groups.

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Palliative procedures, either surgical or transcatheter, aim to improve oxygen saturation, affording definitive procedures at a later stage. Transcatheter interventions have been used before and after surgical palliative or definitive repair in children and adults. This review aims to provide an overview of the different catheter-based interventions for TOF across all age groups, with an emphasis on palliative interventions, such as patent arterial duct stenting, right ventricular outflow tract stenting, or balloon pulmonary valvuloplasty in infants and children and transcatheter pulmonary valve replacement in adults with repaired TOF, including the available options for a large, dilated native right ventricular outflow tract.

Exercise Capacity and Reoperation Late After Transatrial Fallot Repair.

BACKGROUND: The exercise capacity long after repair of tetralogy of Fallot, when performed exclusively with a transatrial repair, is unclear. It is also unknown whether echocardiography and cardiopulmonary exercise testing can predict the risk of reoperation in this patient group. METHOD: We retrospectively reviewed the clinical records of 59 patients who underwent cardiopulmonary exercise testing after transatrial Fallot repair at a single centre. Patients underwent cardiopulmonary exercise testing at a mean age of 16.6±4.4 years, and at 15.3±4.1 years after Fallot repair. RESULTS: At testing, the volume of oxygen consumption at maximal exercise (VO2 max) was 71%±13% and the oxygen pulse was 80%±17% of predicted values. Seventeen (17) patients (29%) had a VO2 max superior to 80% of the predicted value. Thirty-two (32) patients (56%) had severe pulmonary regurgitation, three (5%) had moderate pulmonary regurgitation, and 12 (21%) had mild pulmonary regurgitation. After a mean of 7.8±3.9 years following cardiopulmonary exercise testing (23±5.3 years after the repair), 21 (40%) patients underwent reoperation. Right ventricular dilation and systolic function on echocardiography were both significantly associated with subsequent reoperation rates. Patients who had severe right ventricular dilation were eight times more likely to undergo subsequent reoperation (hazard ratio 8.67; 1.82-41.3; p=0.007). No cardiopulmonary exercise testing variable independently predicted reoperation. CONCLUSIONS: The exercise capacity at adolescence following transatrial repair of tetralogy of Fallot is maintained at around 70% of predicted values. Only the patients with normal right ventricular size and normal right ventricular function seemed to be protected from reoperation over the subsequent decade. We found no exercise variables which predicted reoperation.

The effects of pregnancy in subjects with repaired tetralogy of Fallot.

BACKGROUND: Previous reports reveal inconsistent findings of right ventricular (RV) changes following pregnancy in subjects with repaired tetralogy of Fallot (rTOF). METHODS: A two-center, retrospective cohort study which included women with rTOF who completed pregnancy that were matched to nulliparous women with rTOF by age at the time of baseline cardiac magnetic resonance (CMR), RV ejection fraction (RVEF), and indexed RV end-diastolic volume (RVEDVi). Pre-pregnancy and postpartum cardiac magnetic resonance (CMR) were analyzed and compared to sequential CMR of nulliparous subjects with rTOF. RESULTS: Thirty-six women with rTOF who completed pregnancy were matched to 72 nulliparous women with rTOF. Over a mean period of 3.1 years for the pregnancy group and 2.7 years for the comparison group, there was no significant change in the RVEDVi, RVEF, RV mass, pulmonary regurgitation severity, left ventricular (LV) volumes, LV ejection fraction (LVEF), or LV mass when comparing the baseline CMR and the follow-up CMR in either of the groups. There was a slight increase in RV indexed end-systolic volume (RVESVi) when comparing the baseline CMR and the follow-up CMR in the pregnancy group (68.93, SD 23.34 ml/m2 at baseline vs. 72.97, SD 25.24 mL/m2 at follow-up, P = .028). Using a mixed effects model for CMR parameters change over time; when adjusted for time between baseline and follow-up CMR there was no significant difference in rate of change between the pregnancy and comparison groups. CONCLUSIONS: Most ventricular remodeling parameters measured by CMR did not significantly change in subjects with rTOF who completed pregnancy or in nulliparous subjects with rTOF. In the pregnancy group, RVESVi is larger in those individuals who have undergone pregnancy without a significant change in ventricular function. These patients should be followed longitudinally to determine the long-term ventricular and clinical effects of pregnancy.

Tetralogy of Fallot regurgitation energetics and kinetics: an intracardiac flow analysis of the right ventricle using computational fluid dynamics.

Repaired Tetralogy of Fallot (rTOF) patients suffer from pulmonary regurgitation and may require pulmonary valve replacement (PVR). Cardiac magnetic resonance imaging (cMRI) guides therapy, but conventional measurements do not quantify the intracardiac flow effects from pulmonary regurgitation or PVR. This study investigates intracardiac flow parameters of the right ventricle (RV) of rTOF by computational fluid dynamics (CFD). cMRI of rTOF patients and controls were retrospectively included. Feature-tracking captured RV endocardial contours from long-axis/short-axis cine. Ventricular motion was reconstructed via diffeomorphic mapping, serving as domain boundary for CFD simulations. Vorticity (1/s), viscous energy loss (ELoss, mJ/L) and turbulent kinetic energy (TKE, mJ/L) were quantified in RV outflow tract (RVOT) and RV inflow. These parameters were normalized against total RV kinetic energy (KE) and RV inflow vorticity to derive dimensionless metrics. Vorticity contours by Q-criterion were qualitatively compared. rTOF patients (n = 15) had mean regurgitant fraction 38 ± 12% and RV size 162 ± 35 mL/m2. Compared to controls (n = 12), rTOF had increased RVOT vorticity (142.6 ± 75.6/s vs. 40.4 ± 11.8/s, p < 0.0001), Eloss (55.6 ± 42.5 vs. 5.2 ± 4.4 mJ/L, p = 0.0004), and TKE (5.7 ± 5.9 vs. 0.84 ± 0.46 mJ/L, p = 0.0003). After PVR, there was decrease in normalized RVOT Eloss/TKE (p = 0.0009, p = 0.029) and increase in normalized tricuspid inflow vorticity/KE (p = 0.0136, p = 0.043), corresponding to reorganization of the "donut"-shaped tricuspid ring-vortex. The intracardiac flow in rTOF patients can be simulated to determine the impact of PVR and improve the clinical indications guided by cardiac imaging.

The Ongoing Debate: Longevity of Biological Valves in Pulmonary Position.

BACKGROUND: In patients with tetralogy of Fallot (ToF) or ToF-like anatomy, factors possibly impacting the longevity of biological valves in the pulmonary position were investigated. METHOD: Between 1997 and 2017, 79 consecutive hospital survivors with a median age of 8.7 years (range: 0.2-56.1 years; interquartile range [IQR]: 14.8 years) with ToF or ToF-like anatomy underwent surgical implantation of Contegra (n = 34), Hancock (n = 23), Perimount (n = 9), pulmonary homograft (n = 9), and miscellaneous (n = 4) conduits. The median internal graft diameter was 19 mm (range: 11-29 mm; IQR: 8 mm) which refers to a median z-score of 0.6 standard deviation (SD) (range: -1.8 to 4.0 SD; IQR: 2.1 SD). RESULTS: The median time of follow-up was 9.4 years (range: 1.1-18.8 years; IQR: 6.0 years). Thirty-nine patients (49%) underwent surgical (n = 32) or interventional (n = 7) pulmonary valve re-replacement. Univariate Cox regression revealed patient age (p = 0.018), body surface area (p = 0.004), internal valve diameter (p = 0.005), and prosthesis z-score (p = 0.018) to impact valve longevity. Multivariate Cox regression analysis, however, did not show any significant effect (likely related to multicollinearity). Subgroup analysis showed that valve-revised patients have a higher average z-score (p = 0.003) and younger average age (p = 0.007). CONCLUSION: A decreased longevity of biological valves in the pulmonary position is related to younger age, lower valve diameter, and higher z-score. Because valve size (diameter and z-score) can be predicted by age, patient age is the crucial parameter influencing graft longevity.

Multidetector Computed Tomography Assessment of Anatomical Ventricular Tachycardia Isthmuses in Repaired Tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) is associated with risk for sustained monomorphic ventricular tachycardia (VT). Preemptive electrophysiology study before transcatheter pulmonary valve placement is increasing, but the value of MDCT for anatomical VT isthmus assessment is unknown. OBJECTIVES: The purpose of this study was to determine the impact of multidetector computed tomography (MDCT) in the evaluation of sustained monomorphic VT for repaired TOF. METHODS: Consecutive pre-transcatheter pulmonary valve MDCT studies were identified, and anatomical isthmus dimensions were measured. For a subset of patients with preemptive electrophysiology study, MDCT features were compared with electroanatomical maps. RESULTS: A total of 61 repaired TOFs with MDCT were identified (mean 35 ± 14 years, 58% men) with MDCT electroanatomical map pairs in 35 (57%). Calcification corresponding to patch material was present in 46 (75%) and was used to measure anatomical VT isthmuses. MDCT wall thickness correlated positively with number of ablation lesions and varied with functional isthmus properties (blocked isthmus 2.6 mm [Q1, Q3: 2.1, 4.0 mm], slow conduction 4.8 mm [Q1, Q3: 3.3, 6.0 mm], and normal conduction 5.6 mm [Q1, Q3: 3.9, 8.3 mm]; P < 0.001). A large conal branch was present in 6 (10%) and a major coronary anomaly was discovered in 3 (5%). Median ablation lesion distance was closer to the right vs the left coronary artery (10 mm vs 15 mm; P = 0.01) with lesion-to-coronary distance <5 mm in 3 patients. CONCLUSIONS: MDCT identifies anatomical structures relevant to catheter ablation for repaired TOF. Wall thickness at commonly targeted anatomical VT isthmuses is associated with functional isthmus properties and increased thermal energy delivery.

Flow pattern analysis of right ventricular outflow tract in repaired tetralogy of Fallot through 4D flow MRI.

Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.

Growth of the right ventricular outflow tract in repaired tetralogy of Fallot: A longitudinal CMR study.

BACKGROUND: Many patients with repaired tetralogy of Fallot require pulmonary valve replacement (PVR) due to significant pulmonary regurgitation (PR). Transcatheter PVR (TPVR) is an equally effective and less invasive alternative to surgical PVR but many native right ventricular outflow tracts (RVOTs) are too large for TPVR at time of referral. Understanding the rate of growth of the RVOT may help optimize timing of referral. This study aims to examine the longitudinal growth of the native RVOT over time in repaired tetralogy of Fallot (TOF). METHODS: A retrospective review of serial cardiac MRI cardiovascular magnetic resonance (CMR) data from 121 patients with repaired TOF and a native RVOT (median age at first CMR 14.7 years, average interval between the first and last CMR of 8.1 years) was performed to measure serial changes in RVOT diameter, cross-sectional area, perimeter-derived diameter, and length. RESULTS: All parameters of RVOT size continued to grow with increasing age but growth was more rapid in the decade after TOF repair (for minimum systolic diameter, mean increase of 5.7 mm per 10 years up to year 12, subsequently 2.3 mm per 10 years). The RVOT was larger with a transannular patch and in patients without pulmonary stenosis (p < 0.001 for both), but this was not associated with rate of growth. More rapid RVOT enlargement was noted in patients with larger right ventricular end-diastolic volume (RVEDV), higher PR fraction, and greater rates of increases in RVEDV and PR (p < 0.001 for all) CONCLUSIONS: in patients with repaired TOF, using serial CMR data, we found that RVOT size increased progressively at all ages, but the rate was more rapid in the first decade after repair. More rapid RVOT enlargement was noted in patients with a larger RV, more PR, and greater rates of increases in RV size and PR severity. These results may be important in considering timing of referral for transcatheter pulmonary valves, in planning transcatheter and surgical valve replacement, and in designing future valves for the native RVOT.

Assessment of right ventricular diastolic function in pediatric patients with repaired tetralogy of Fallot by cardiovascular magnetic resonance and echocardiography.

OBJECTIVES: Cardiovascular magnetic resonance (CMR) imaging is routinely performed for assessing right ventricular (RV) systolic but not diastolic function. We aimed to investigate CMR-based assessment of RV diastolic function in pediatric patients with repaired tetralogy of Fallot (rTOF), compared to transthoracic echocardiography (TTE) measurements. METHODS: A total of 130 consecutive pediatric patients with rTOF who underwent clinically indicated CMR and same-day TTE were included. Forty-three controls were recruited. Phase-contrast images were used to measure trans-tricuspid valve flow velocities during early (E) and late diastolic (A) phases (measured in cm/s). Feature tracking of the tricuspid annulus was performed to derive early (e') and late diastolic (a') myocardial velocities (measured in cm/s). RV diastolic function was evaluated by E/A ratio, E/e' ratio, and E-wave deceleration time (measured in milliseconds). Regression analyses were utilized to identify potential variables associated with RV diastolic dysfunction (DD). The performance of CMR-derived parameters in diagnosing RV DD was assessed using receiver-operating characteristic analyses. RESULTS: Good agreement was found between CMR and TTE measurements (ICC 0.70-0.89). Patients with RV DD (n = 67) showed significantly different CMR-derived parameters including E and e' velocities, and E/A and E/e' ratio, compared to patients without DD (n = 63) (all p < 0.05). CMR-derived E and e' velocities and E/e' ratio were independent predictors of RV DD. E/e' of 5.8 demonstrated the highest discrimination of RV DD (AUC 0.76, sensitivity 70%, specificity 86%). CONCLUSIONS: CMR-derived parameters showed good agreement with TTE parameters in determining RV DD. CMR-derived E/e' was proved to be the most effective in identifying RV DD. CLINICAL RELEVANCE STATEMENT: This study demonstrated the feasibility and efficacy of CMR in assessing diastolic function in pediatric patients. RV DD was presented in over half of patients according to current TTE guidelines, highlighting the need for assessing RV diastolic function during follow-up. KEY POINTS: • Routinely acquired cine and phase-contrast cardiovascular magnetic resonance (CMR) images yielded right ventricular (RV) diastolic parameters which demonstrated good agreement with transthoracic echocardiography (TTE) measurements. • There was a high prevalence of RV diastolic function impairment in pediatric patients with repaired tetralogy of Fallot (rTOF). • CMR is a reliable complementary modality of TTE for RV diastolic function evaluation.

Comparison of management strategies for neonates with symptomatic tetralogy of Fallot and weight <2.5 kg.

OBJECTIVE: To compare management strategies for neonates <2.5 kg with tetralogy of Fallot and symptomatic cyanosis who either undergo staged repair (SR) (initial palliation followed by later complete repair) or primary repair (PR). METHODS: Consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing <2.5 kg at initial intervention and between 2005 and 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Primary outcome was mortality and secondary outcomes included component (eg, initial palliation, complete repair, or primary repair) and cumulative (SR: initial palliation followed by later complete repair) hospital and intensive care unit lengths of stay, durations of ventilation, inotrope use, cardiopulmonary bypass time, procedural complications, and reintervention. Outcomes were compared with propensity score adjustments with PR as the reference group. RESULTS: The cohort included 76 SR (initial palliation: 53 surgical and 23 transcatheter) and 44 PR patients. The observed risk of overall mortality was similar between SR and PR groups (15.8% vs 18.2%: P = .735). The adjusted hazard of mortality remained similar between groups overall (hazard ratio, 0.59; 95% confidence interval, 0.26-1.36; P = .214), as well as during short-term (<4 months: hazard ratio, 0.37; 95% confidence interval, 0.13-1.09; P = .071) and midterm (>4 months: hazard ratio, 1.32; 95% confidence interval, 0.30-5.79; P = .717) follow-up. Reintervention in the first 18 months was common in both groups (53.2% vs 48.4%; hazard ratio, 1.69; 95% confidence interval, 0.96-2.28; P = .072). Adjusted procedural complications and neonatal morbidity burden were overall lower in the SR group. Cumulative secondary outcome burdens largely favored the PR group. CONCLUSIONS: In this study comparing SR and PR treatment strategies for neonates with tetralogy of Fallot and symptomatic cyanosis and weight <2.5 kg, mortality and reintervention burden was high and independent of treatment strategy. Other potential advantages were observed with each approach.

Unchanged right ventricular strain in repaired tetralogy of Fallot after pulmonary valve replacement with radial long-axis cine magnetic resonance images.

We measured right ventricular (RV) strain by applying a novel postprocessing technique to conventional short-axis cine magnetic resonance imaging in the repaired tetralogy of Fallot (TOF) and investigated whether pulmonary valve replacement (PVR) changes the RV strain. Twenty-four patients with repaired TOF who underwent PVR and 16 healthy controls were enrolled. Global maximum and minimum principal strains (GPSmax, GPSmin) and global circumferential and longitudinal strains (GCS, GLS) were measured from short-axis cine images reconstructed radially along the long axis. Strain parameters before and after PVR were compared using paired t-tests. One-way ANOVA with Tukey post-hoc analysis was used for comparisons between the before and after PVR groups and the control group. There were no differences in strain parameters before and after PVR. The GPSmax before PVR was lower than that in the control group (P = 0.002). Before and after PVR, GCSs were higher and GLSs were lower than those in the control group (before and after GCSs: P = 0.002 for both, before and after GLSs: P < 0.0001 and P = 0.0003). RV strains from radially reconstructed short-axis cine images revealed unchanged myocardial motion after PVR. When compared to the control group, changes in GCS and GLS in TOF patients before and after PVR might be due to RV remodeling.

Biventricular Global Function Index Is Associated With Adverse Outcomes in Repaired Tetralogy of Fallot.

INTRODUCTION: Cardiac magnetic resonance (CMR) derived biventricular global function index (BVGFI) is a new CMR parameter that integrates biventricular volumes, mass, and function using clinically available CMR parameters. The associations of BVGFI with clinical outcomes in repaired tetralogy of Fallot are unknown. METHODS: Patients with repaired tetralogy of Fallot who had a CMR before the occurrence of a composite outcome of death, resuscitated sudden death, or sustained ventricular tachycardia were studied. BVGFI was calculated as the average of right and left GFI. GFI was defined as (ventricular stroke volume×100)/(ventricular mean cavity volume + total ventricular myocardial volume). Ventricular mean cavity volume was defined as ([end-diastolic + end-systolic volume]/2). Cox multivariable regression analysis and classification and regression tree methodology were used. RESULTS: Of the 736 eligible subjects (mean age at CMR 25.4±14.5 years), with a median follow-up of 28 months, 55 subjects (7.4%) reached the composite outcome (46 deaths and 9 sustained ventricular tachycardia). Independent associations with the composite outcome were as follows: BVGFI <37 (hazard ratio, 2.52; P=0.004), right ventricular end-systolic volume index >85 mL/m2 (hazard ratio, 3.25; P<0.001), atrial tachycardia (hazard ratio, 2.03; P=0.021), and age at repair >2.5 years (hazard ratio, 3.37; P<0.001). Classification and regression tree analysis identified BVGFI as the most discriminatory CMR parameter associated with a high risk for adverse outcomes. CONCLUSIONS: BVGFI, a novel CMR-derived imaging biomarker combining biventricular volumes, mass, and function, may improve risk stratification for adverse clinical outcomes in patients with repaired tetralogy of Fallot.