Repaired Tetralogy of Fallot: Have We Understood the Right Timing of PVR?

Despite many advances in surgical repair during the past few decades, the majority of tetralogy of Fallot patients continue to experience residual hemodynamic and electrophysiological abnormalities. The actual issue, which has yet to be solved, is understanding how this disease evolves in each individual patient and, as a result, who is truly at risk of sudden death, as well as the proper timing of pulmonary valve replacement (PVR). Our responsibility should be to select the most appropriate time for each patient, going above and beyond imaging criteria used up to now to make such a clinically crucial decision. Despite several studies on timing, indications, procedures, and outcomes of PVR, there is still much uncertainty about whether PVR reduces arrhythmia burden or improves survival in these patients and how to appropriately manage this population. This review summarizes the most recent research on the evolution of repaired tetralogy of Fallot (from adolescence onwards) and risk factor variables that may favor or delay PVR.

Cardiopulmonary Exercise Testing after Surgical Repair of Tetralogy of Fallot-Does Modality Matter?

BACKGROUND: Despite a successful repair of tetralogy of Fallot (rToF) in childhood, residual lesions are common and can contribute to impaired exercise capacity. Although both cycle ergometer and treadmill protocols are often used interchangeably these approaches have not been directly compared. In this study we examined cardiopulmonary exercise test (CPET) measurements in rToF. METHODS: Inclusion criteria were clinically stable rToF patients able to perform a cardiac magnetic resonance imaging (CMR) and two CPET studies, one on the treadmill (incremental Bruce protocol) and one on the cycle ergometer (ramped protocol), within 12 months. Demographic, surgical and clinical data; functional class; QRS duration; CMR measures; CPET data and international physical activity questionnaire (IPAQ) scores of patients were collected. RESULTS: Fifty-seven patients were enrolled (53% male, 20.5 ± 7.8 years at CPET). CMR measurements included a right ventricle (RV) end-diastolic volume index of 119 ± 22 mL/m2, a RV ejection fraction (EF) of 55 ± 6% and a left ventricular (LV) EF of 56 ± 5%. Peak oxygen consumption (VO2)/Kg (25.5 ± 5.5 vs. 31.7 ± 6.9; p < 0.0001), VO2 at anaerobic threshold (AT) (15.3 ± 3.9 vs. 22.0 ± 4.5; p < 0.0001), peak O2 pulse (10.6 ± 3.0 vs. 12.1± 3.4; p = 0.0061) and oxygen uptake efficiency slope (OUES) (1932.2 ± 623.6 vs. 2292.0 ± 639.4; p < 0.001) were significantly lower on the cycle ergometer compared with the treadmill, differently from ventilatory efficiency (VE/VCO2) max which was significantly higher on the cycle ergometer (32.2 ± 4.5 vs. 30.4 ± 5.4; p < 0.001). Only the VE/VCO2 slope at the respiratory compensation point (RCP) was similar between the two methodologies (p = 0.150). CONCLUSIONS: The majority of CPET measurements differed according to the modality of testing, with the exception being the VE/VCO2 slope at RCP. Our data suggest that CPET parameters should be interpreted according to test type; however, these findings should be validated in larger populations and in a variety of institutions.

The mechanics of congenital heart disease: from a morphological trait to the functional echocardiographic evaluation.

Advances in pediatric cardiac surgery have resulted in a recent growing epidemic of children and young adults with congenital heart diseases (CHDs). In these patients, congenital defects themselves, surgical operations and remaining lesions may alter cardiac anatomy and impact the mechanical performance of both ventricles. Cardiac function significantly influences outcomes in CHDs, necessitating regular patient follow-up to detect clinical changes and relevant risk factors. Echocardiography remains the primary imaging method for CHDs, but clinicians must understand patients' unique anatomies as different CHDs exhibit distinct anatomical characteristics affecting cardiac mechanics. Additionally, the use of myocardial deformation imaging and 3D echocardiography has gained popularity for enhanced assessment of cardiac function and anatomy. This paper discusses the role of echocardiography in evaluating cardiac mechanics in most significant CHDs, particularly its ability to accommodate and interpret the inherent anatomical substrate in these conditions.

Adherence to clinical practice guidelines for pulmonary valve intervention after tetralogy of Fallot repair: A nationwide cohort study.

Objectives: To determine guideline adherence pertaining to pulmonary valve replacement (PVR) referral after tetralogy of Fallot (TOF) repair. Methods: Children and adults with cardiovascular magnetic resonance imaging scans and at least moderate pulmonary regurgitation were prospectively enrolled in the Comprehensive Outcomes Registry Late After TOF Repair (CORRELATE). Individuals with previous PVR were excluded. Patients were classified according to presence (+) versus absence (-) of PVR and presence (+) versus absence (-) of contemporaneous guideline satisfaction. A validated score (specific activity scale [SAS]) classified adult symptom status. Results: In total, 498 participants (57% male, mean age 32 ± 14 years) were enrolled from 14 Canadian centers (2013-2020). Mean follow-up was 3.8 ± 1.8 years. Guideline criteria for PVR were satisfied for the majority (n = 422/498, 85%), although referral for PVR occurred only in a minority (n = 167/498, 34%). At PVR referral, most were asymptomatic (75% in SAS class 1). One participant (0.6%) received PVR without meeting criteria (PVR+/indication-). The remainder (n = 75/498, 15%) did not meet criteria for and did not receive PVR (PVR-/indication-). Abnormal cardiovascular imaging was the most commonly cited indication for PVR (n = 61/123, 50%). The SAS class and ratio of right to left end-diastolic volumes were independent predictors of PVR in a multivariable analysis (hazard ratio, 3.33; 95% confidence interval, 1.92-5.8, P < .0001; hazard ratio, 2.78; 95% confidence interval, 2.18-3.55, P < .0001). Conclusions: Although a majority of patients met guideline criteria for PVR, only a minority were referred for intervention. Abnormal cardiovascular imaging was the most common indication for referral. Further research will be necessary to establish the longer-term clinical impact of varying PVR referral strategies.

Double-Outlet Left Ventricle: Case Series and Systematic Review of the Literature.

Double-outlet left ventricle (DOLV) is an abnormal ventriculo-arterial connection characterized by the origin of both great arteries from the morphological left ventricle. The aim of our paper is to describe the morphological and imaging features of DOLV and to assess the prevalence of the associated malformations and their surgical outcomes. METHODS From 2011 to 2022, we retrospectively reviewed the electronic case records of patients diagnosed with DOLV at the Bambino Gesu Children's Hospital. A systematic search was developed in MEDLINE, Web of Science, and EMBASE databases to identify reports assessing the morphology and outcomes of DOLV between 1975 and 2023. RESULTS: Over a median follow-up of 9.9 years (IQR 7.8-11.7 y), four cases of DOLV were identified at our institution. Two patients were diagnosed with (S,D,D) DOLV subaortic VSD and pulmonary stenosis (PS): one patient had (S,D,D) DOLV with doubly committed VSD and hypoplastic right ventricle, and another patient had (S,D,L) DOLV with subaortic VSD and PS (malposition type). Pulmonary stenosis was the most commonly associated lesion (75%). LITERATURE REVIEW: After systematic evaluation, a total of 12 reports fulfilled the eligibility criteria and were included in our analysis. PS or right ventricular outflow tract obstruction was the most commonly associated lesion (69%, 95% CI 62-76%). The most common locations of VSD were subaortic (pooled prevalence: 75%, 95% CI 68-81), subpulmonary (15%, 95% CI 10-21), and doubly committed (7%, 95% CI 4-12). The position of the great arteries showed that d-transposition of the aorta was present in 128 cases (59% 95% CI 42-74), and l-transposition was present in 77 cases (35%, 95% CI 29-43).

Overcoming Underpowering in the Outcome Analysis of Repaired-Tetralogy of Fallot: A Multicenter Database from the CMR/CT Working Group of the Italian Pediatric Cardiology Society (SICPed).

Background: Managing repaired tetralogy of Fallot (TOF) patients is still challenging despite the fact that published studies identified prognostic clinical or imaging data with rather good negative predictive accuracy but weak positive predictive accuracy. Heterogeneity of the initial anatomy, the surgical approach, and the complexity of the mechanism leading to dilation and ventricular dysfunction explain the challenge of predicting the adverse event in this population. Therefore, risk stratification and management of this population remain poorly standardized. Design: The CMR/CT WG of the Italian Pediatric Cardiology Society set up a multicenter observational clinical database of repaired TOF evaluations. This registry will enroll patients retrospectively and prospectively assessed by CMR for clinical indication in many congenital heart diseases (CHD) Italian centers. Data collection in a dedicated platform will include surgical history, clinical data, imaging data, and adverse cardiac events at 6 years of follow-up. Summary: The multicenter repaired TOF clinical database will collect data on patients evaluated by CMR in many CHD centers in Italy. The registry has been set up to allow future research studies in this population to improve clinical/surgical management and risk stratification of this population.

Patient-Reported Outcomes After Tetralogy of Fallot Repair.

BACKGROUND: Comprehensive assessment of tetralogy of Fallot (TOF) outcomes extends beyond morbidity and mortality to incorporate patient-reported outcomes (PROs), including quality of life (QOL) and health status (HS). OBJECTIVES: This study explored PROs in adolescents and adults with TOF and delineated variables associated with PROs. METHODS: This was a cross-sectional observational study within a larger prospective registry of adolescents and adults with repaired TOF and moderate or greater pulmonary regurgitation from North America, Europe, and Asia. Participants completed PROs, including a QOL linear analogue scale (QOL-LAS) and an HS visual analogue scale (HS-VAS). Scores were classified according to age cohorts: <18, 18 to 25, 26 to 40, and >40 years. RESULTS: The study included 607 patients (46.3% female; median age 28.5 years). Median QOL-LAS scores (0-100) were similar across age cohorts (85, 80, 80, 80; P = 0.056). Median HS-VAS scores (0-100) were lowest for the oldest cohort (77) compared with the 3 younger cohorts (85, 80, 80) (P = 0.004). With advancing age, there were increased reports of poor mobility (P < 0.001) and pain or discomfort (P = 0.004); problems in these dimensions were reported by 19.1% and 37.2% of patients aged >40 years, respectively. Of factors associated with superior PROs on multivariable regression modeling (ie, being White, being nonsyndromic, having employment, and having better left ventricular function; P < 0.05), asymptomatic status (functional class I) was the variable associated with the greatest number of QOL and HS measures (P < 0.001). CONCLUSIONS: Strategies to improve TOF outcomes should consider PROs alongside conventional clinical variables. Factors associated with poorer PROs represent opportunities to intervene to improve the lives of patients with TOF.

Non-Invasive Imaging Assessment in Patients with Aortic Coarctation: A Contemporary Review.

Coarctation of the aorta (CoA) is a congenital abnormality characterized by a narrowing of the aortic lumen, which can lead to significant morbidity and mortality if left untreated. Even after repair and despite significant advances in therapeutic management, these patients have overall reduced long-term survival due to the consequences of chronic afterload increase. Cardiovascular imaging is key from the first diagnosis to serial follow-up. In recent years, novel imaging techniques have emerged, increasing accessibility to advanced imaging modalities and enabling early and non-invasive identification of complications after repair. The aim of this paper is to provide a comprehensive review of the role of different imaging techniques in the evaluation and management of patients with native or repaired CoA, highlighting their unique strengths and limitations.

The Role of Cardiopulmonary Testing to Risk Stratify Tetralogy of Fallot Patients.

Neonatal repair has completely changed the clinical history of patients with tetralogy of Fallot (ToF); however, these patients carry a significant risk of severe arrhythmias and sudden cardiac death in the long term. The exact mechanism for late sudden cardiac death is multifactorial and still not well defined, and the risk stratification for primary prophylaxis in these patients remains challenging. Cardiopulmonary exercise testing (CPET) is a well-established and safe method to assess cardiopulmonary function in children and adults with congenital heart disease. Several parameters obtained with CPET have been identified as potential prognostic of major adverse cardiovascular events in congenital heart disease. CPET is routinely used to assess functional capacity also in patients with ToF, and there is some evidence showing its usefulness in predicting the cardiac adverse events in patients with repaired ToF. Current guidelines recognize the importance of CPET in the evaluation and management of patients with ToF, but there is no clear consensus on which the CPET parameter or level of exercise intolerance, as measured by CPET, is truly predictive of an increased risk of arrhythmia and major adverse cardiovascular events in this population. Therefore, the aim of this narrative review is to describe the current evidence on the potential use of CPET in the risk stratification of patients with repaired ToF.

La chirurgie réparatrice néonatale a complètement changé le parcours clinique des patients nés avec une tétralogie de Fallot (TF). Ces patients demeurent toutefois exposés à un risque important d'arythmie sévère et de mort cardiaque subite (MCS) à long terme. Le mécanisme causal exact de la MCS tardive est multifactoriel et demeure mal défini, ce qui complique la stratification du risque pour le traitement préventif primaire chez ces patients. L'épreuve d'effort cardiorespiratoire (EECR) est une méthode sécuritaire et bien établie pour évaluer la fonction cardiopulmonaire des enfants et des adultes atteints de cardiopathie congénitale (CC). Plusieurs paramètres obtenus lors d'une EECR ont été décrits comme des marqueurs pronostiques potentiels d'événements cardiovasculaires indésirables majeurs (ECIM) en contexte de CC. L'EECR est couramment utilisée pour évaluer la capacité fonctionnelle des patients atteints de TF et des données probantes démontrent son utilité pour prédire les manifestations cardiaques défavorables chez les patients opérés d'une TF. Les lignes directrices en vigueur conviennent de l'importance de l'EECR dans l'évaluation et la prise en charge des patients opérés d'une TF, mais il n'existe aucun consensus clair sur le paramètre ou le seuil d'intolérance à l'effort mesuré par l'EECR qui possède une réelle valeur prédictive d'un risque élevé d'arythmie et d'ECIM dans cette population. L'objectif de la présente synthèse narrative est de décrire les données probantes actuelles sur l'utilisation potentielle de l'EECR dans la stratification du risque chez les patients opérés d'une TF.

Soluble Isoform of Suppression of Tumorigenicity 2 (ST2) Biomarker in a Large Cohort of Healthy Pediatric Population: Determination of Reference Intervals.

Introduction: Only little data exists on ST2 reference intervals in healthy pediatric populations despite the high importance of this biomarker in adults with heart failure. The aim of the study was to assess the reference intervals of ST2 in a wide healthy pediatric cohort. Methods: We evaluated the serum concentrations of ST2 biomarker in 415 healthy pediatric subjects referred to our analysis laboratory. Subjects were categorized according to age (i.e., 0−6 (n = 79), 7−11 (n = 142) and 12−18 years (n = 191)) and sex. They were not suffering from any cardiac disorders, metabolic disorders, lung diseases, autoimmune disorders or malignancies. A written consent was obtained for each individual. No duplicate patients were included in the analysis and the presence of outliers was investigated. Reference intervals (Mean and central 95% confidence intervals) were determined. Results: Three outliers have been identified and removed from the analysis (60.0, 64.0 and 150.2 ng/mL). A total of 412 subjects were therefore included. The mean value for the whole population was 15.8 ng/mL (2.4−36.4 ng/mL). Males present a significantly higher mean concentration compared to females (17.2 versus 14.4 ng/mL, p = 0.001). A significant trend toward higher ST2 values with age was also observed, but for males only (r = 0.43, p < 0.0001). If considering age partitions, only males of 12−18 years (mean = 21.7 ng/mL) had significantly higher ST2 values compared to the other groups (ranging from 11.9 for males 0−6 years to 15.2 for females 12−18 years; p < 0.0001). Conclusions: We described age and sex-specific reference intervals for ST2 in a large healthy pediatric population. We found that ST2 values differ between sexes if considering all participants. A significant increase in ST2 with age was also observed, but only for males of 12−18 years.

Syndromic and Non-Syndromic Patients with Repaired Tetralogy of Fallot: Does It Affect the Long-Term Outcome?

BACKGROUND: The impact of genetic syndromes on cardiac magnetic resonance imaging (cMRI) parameters, particularly on right and/or left ventricular dysfunction, associated with clinical parameters following the repair of Tetralogy of Fallot (rToF) is not well known. Therefore, this study aimed to assess the differences in clinical, surgical, and cMRI data in syndromic and non-syndromic rToF patients. METHODS: All syndromic rToF patients undergoing a cMRI without general anesthesia between 2010 and 2020 who were able to match with non-syndromic ones for birth date, sex, type of surgery, timing of cMRI, and BSA were selected. Demographic, clinical, surgical, MRI, ECG, and Holter ECG data were collected. RESULTS: A total of one hundred and eight rToF patients equally subdivided into syndromic and non-syndromic, aged 18.7 ± 7.3 years, were studied. Del22q11.2 and Down syndrome (DS) were the most frequent syndromes (42.6% and 31.5%, respectively). Regarding the cMRI parameters considered, left ventricular (LV) dysfunction (LVEF < 50%) was more frequently found in syndromic patients (p = 0.040). In addition, they were older at repair (p = 0.002) but underwent earlier pulmonary valve replacement (PVR) (15.9 ± 5.6 vs. 19.5 ± 6.0 years, p = 0.049). On multivariate Cox regression analysis, adjusted for age at first repair, LV dysfunction remained significantly more associated with DS than del22q11.2 and non-syndromic patients (HR of 5.245; 95% CI 1.709-16.100, p = 0.004). There were only four episodes of non-sustained ventricular tachycardia in our cohort. CONCLUSIONS: Among the cMRI parameters commonly taken into consideration in rToF patients, LV dysfunction seemed to be the only one affected by the presence of a genetic syndrome. The percentage of patients performing PVR appears to be similar in both populations, although syndromic patients were older at repair and younger at PVR. Finally, the number of arrhythmic events in rToF patients seems to be low and unaffected by chromosomal abnormalities.

Cardiopulmonary Exercise Testing in Repaired Tetralogy of Fallot: Multiparametric Overview and Correlation with Cardiac Magnetic Resonance and Physical Activity Level.

Patients with repaired Tetralogy of Fallot (rToF) typically report having preserved subjective exercise tolerance. Chronic pulmonary regurgitation (PR) with varying degrees of right ventricular (RV) dilation as assessed by cardiac magnetic resonance imaging (MRI) is prevalent in rToF and may contribute to clinical compromise. Cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capacity, and the International Physical Activity Questionnaire (IPAQ) can provide additional data on physical activity (PA) achieved. Our aim was to assess the association between CPET values, IPAQ measures, and MRI parameters. All rToF patients who had both an MRI and CPET performed within one year between March 2019 and June 2021 were selected. Clinical data were extracted from electronic records (including demographic, surgical history, New York Heart Association (NYHA) functional class, QRS duration, arrhythmia, MRI parameters, and CPET data). PA level, based on the IPAQ, was assessed at the time of CPET. Eighty-four patients (22.8 ± 8.4 years) showed a reduction in exercise capacity (median peak VO2 30 mL/kg/min (range 25-33); median percent predicted peak VO2 68% (range 61-78)). Peak VO2, correlated with biventricular stroke volumes (RVSV: ß = 6.11 (95%CI, 2.38 to 9.85), p = 0.002; LVSV: ß = 15.69 (95% CI 10.16 to 21.21), p < 0.0001) and LVEDVi (ß = 8.74 (95%CI, 0.66 to 16.83), p = 0.04) on multivariate analysis adjusted for age, gender, and PA level. Other parameters which correlated with stroke volumes included oxygen uptake efficiency slope (OUES) (RVSV: ß = 6.88 (95%CI, 1.93 to 11.84), p = 0.008; LVSV: ß = 17.86 (95% CI 10.31 to 25.42), p < 0.0001) and peak O2 pulse (RVSV: ß = 0.03 (95%CI, 0.01 to 0.05), p = 0.007; LVSV: ß = 0.08 (95% CI 0.05 to 0.11), p < 0.0001). On multivariate analysis adjusted for age and gender, PA level correlated significantly with peak VO2/kg (ß = 0.02, 95% CI 0.003 to 0.04; p = 0.019). We observed a reduction in objective exercise tolerance in rToF patients. Biventricular stroke volumes and LVEDVi were associated with peak VO2 irrespective of RV size. OUES and peak O2 pulse were also associated with biventricular stroke volumes. While PA level was associated with peak VO2, the incremental value of this parameter should be the focus of future studies.

Risk Factors of Right Ventricular Dysfunction and Adverse Cardiac Events in Patients with Repaired Tetralogy of Fallot.

AIM: This study evaluates the risk factors associated with right ventricular (RV) dilation and dysfunction leading to pulmonary valve replacement (PVR) or adverse cardiac events in repaired Tetralogy of Fallot (rToF) patients. METHODS: Data from all rToF patients who underwent magnetic resonance imaging (MRI) evaluation at our hospital between February 2007 and September 2020 were collected. RESULTS: Three hundred and forty-two patients (60% males, 42% older than 18 years), with a median age of 16 years (IQR 13-24) at the time of MRI, were included. All patients underwent complete repair at a median age of 8 months (IQR 5-16), while palliation was performed in 56 patients (16%). One hundred and forty-four patients (42%) subsequently received pulmonary valve replacement (PVR). At the multivariate analysis, male gender was an independent predictor for significant RV dilation, RV and left ventricular (LV) dysfunction. Transventricular ventricular septal defect (VSD) closure and previous palliation significantly affected LV function and RV size, respectively. Male gender and the transventricular VSD closure were independent predictors for PVR. CONCLUSIONS: Male gender and surgical history (palliation, VSD closure approach) significantly affected the long-term outcomes in rToF patients and should be taken into consideration in the follow-up management and in PVR timing in this patient population.

The Effects of Physical Inactivity and Exercise at Home in Young Patients with Congenital Heart Disease during the COVID-19 Pandemic.

Background: The COVID-19 pandemic had a significant impact on the population's ability to be physically active. Purpose: Evaluate the effect of the COVID-19 mitigation measures on exercise tolerance in patients with congenital heart disease (CHD). Materials and methods: All subjects (880, 6-18 years old) who performed a stress test at our hospital from October 2020 to February 2021 and had a similar test one year earlier were enrolled. A questionnaire on the degree of physical activity carried out in 2020 concerning the period prior to the pandemic was compiled. Exercise tolerance and the main anthropometric parameters between the first and second tests were compared. Results: 110 subjects (11.9 ± 4.1 years) were included in the study. The percentage of patients engaged in regular physical activity (RPA) decreased significantly during the pandemic (p < 0.001), and BMI increased significantly (p < 0.001), except among the subjects who began RPA during the lockdown, whereas test duration did not decrease significantly overall but increased in this last subgroup (p < 0.05) Conclusions: The COVID-19 lockdown led to a less active lifestyle with a significant increase in BMI in our group of CHD. These data could have negative effects on the risk profile of this population. RPA practiced at home seems to be effective in counteracting such effects.

Right ventricular dilatation in patients with pulmonary regurgitation after repair of tetralogy of Fallot: How fast does it progress?

OBJECTIVE: Pulmonary valve regurgitation (PR) and right ventricular (RV) dilatation are important residual findings after surgical repair of tetralogy of Fallot (TOF). We sought to describe the natural course of RV dilatation over time in patients with severe PR after TOF repair and to determine risk factors for quick progression of RV dilatation and dysfunction. METHODS: Data of 85 consecutive TOF patients with PR and RV dilatation, undergoing serial cardiovascular magnetic resonance (CMR) scans between July 2002 and December 2016 in two institutions, were retrospectively reviewed. The dataset was analyzed regarding right and left ventricular (LV) volume and function and potential risk factors of progressive RV dilatation. RESULTS: There was no significant increase in RV end-diastolic volumes (RVEDVi) indexed body surface area (BSA) (median 150 [81-249] vs. 150 [82-260] mL/m2) and end-systolic volumes indexed for BSA (RVESVi) (75 [20-186] vs. 76 [39-189] mL/m2) between the first and last CMR in the overall group. Similarly, there were no significant changes in LV volumes indexed for BSA (LVEDVi 78 [56-137] vs. 81 [57-128] mL/m2 and LV end-systolic volume index 34 [23-68] vs. 35 [18-61] mL/m2). Global function remained also unchanged for both ventricles. RVEDVi increased statistically significantly (≥20 mL/m2) in twenty patients (24%) from 154 mL/m2 (87-237) to 184 mL/m2 (128-260, P < 0.001). LV dimensions showed a similar trend with LVEDVi increase from 80 ml/m2 (57-98) to 85 ml/m2 (72-105, P = 0.002). Shorter time interval between repair and first CMR was the only risk factor predictive for progressive RV dilatation. CONCLUSION: In the majority of patients with repaired TOF and severe PR, RV dilatation is unchanged during a follow-up of 3 years. RV dilatation seems to progress early after surgery and subsequently stabilize. RV dilatation significantly progresses in a subgroup of 24% of patients, with a shorter time interval since surgical repair.

Patient-specific three-dimensional aortic arch modeling for automatic measurements: clinical validation in aortic coarctation.

AIM: A validated algorithm for automatic aortic arch measurements in aortic coarctation (CoA) patients could standardize procedures for clinical planning. METHODS: The model-based assessment of the aortic arch anatomy consisted of three steps: first, machine-learning-based algorithms were trained on 212 three-dimensional magnetic resonance (MR) data to automatically allocate the aortic arch position in patients and segment the aortic arch; second, for each CoA patient (N = 33), the min/max aortic arch diameters were measured using the proposed software, manually and automatically, from noncontrast-enhanced three-dimensional steady-state free precession MRI sequence at five selected sites and compared ('internal comparison' referring to the same environment); third, moreover, the same min/max aortic arch diameters were compared, obtaining them independently, manually from common MR management software (MR Viewforum) and automatically from the model (external comparison). The measured sites were: aortic sinus, sino-tubular junction, mid-ascending aorta, transverse arch and thoracoabdominal aorta at the level of the diaphragm. RESULTS: Manual and software-assisted measurements showed a good agreement: the difference between diameter measurements was not statistically significant (at α = 0.05), with only one exception, for both internal and external comparison. A high coefficient of correlation was attained for both maximum and minimum diameters in each site (for internal comparison, R > 0.73 for every site, with P < 2 × 10). Notably, in tricuspid aortic valve patients external comparison showed no statistically significant difference at any measurement sites. CONCLUSION: The automatically derived aortic arch model, starting from three-dimensional MR images, could be a support to take the measurements in CoA patients and to quickly provide a patient-specific model of aortic arch anomalies.

Role of cardiovascular magnetic resonance end-systolic 3D-SSFP sequence in repaired tetralogy of Fallot patients eligible for transcatheter pulmonary valve implantation.

To evaluate the usefulness of cardiovascular magnetic resonance (CMR) 3D steady state free precession (SSFP) sequence acquired at end-systole (ES) in repaired Tetralogy of Fallot (rToF) patients eligible for percutaneous pulmonary valve implantation (PPVI). Between 2012 and 2018, 78 rToF patients were selected for pulmonary valve replacement (PVR) according to CMR criteria. CMR protocol included 3D-SSFP sequence used to assess the right ventricle outflow tract (RVOT) diameters at three levels (pulmonary valve remnant, mid-portion, bifurcation) in mid-diastole (MD) or ES, RVOT length and coronary artery anatomy. In 20 rToF patients without indications for PVR (controls), 3D SSFP sequence was acquired at both cardiac phases (MD and ES) to evaluate RVOT dimension throughout the cardiac cycle. Invasive balloon sizing was recorded in patients undergoing PPVI. The 3D-SSFP sequence was performed in MD on 39 patients and in ES on other 39, of whom 26 patients met the criteria for PPVI. The latter was unsuccessful in ten patients (38%), mainly due (80% of cases) to significant size discrepancy at PV remnant and bifurcation levels (p = 0.019 and 0.037 respectively) between the measurements by 3D-SSFP in MD and those by the balloon size in systole. Significant RVOT size difference between MD and ES was present at mid-portion and bifurcation levels in the PVR candidate group, and at all three-levels in the control group (all p < 0.001). ES 3D-SSFP sequence is able to quantify RVOT dilation in rToF patients at its maximum expansion, thus improving selection of PPVI candidates.

Improving the role of echocardiography in studying the right ventricle of repaired tetralogy of Fallot patients: comparison with cardiac magnetic resonance.

Right ventricular (RV) evaluation represents one of the major clinical tasks in the follow-up of repaired tetralogy of Fallot patients (rToF) with pulmonary valve regurgitation, as both severe RV dilatation and dysfunction are key factors in defining the need of pulmonary valve replacement. The aim of our study was to report the diagnostic accuracy of echocardiography in the identification of rToF patients with severely dilated and/or depressed RV as compared to cardiac magnetic resonance (CMR). Among our patients with rToF, a subgroup of 95 (17.6 ± 6.8 years; 60% male), who underwent right ventricular qualitative and quantitative evaluation with CMR following echocardiographic suspicion of severe dilation/dysfunction, were included in the analysis. When comparing echocardiographic RV functional parameters to CMR findings, we found no association between CMR-ejection fraction (EF) and either tricuspid annulus plane systolic excursion (TAPSe) nor tissue Doppler systolic tricuspid excursion velocity (all p = ns). In contrast RVFAC was strongly associated with CMR-EF (r = 0.44; p < 0.01) as well as to longitudinal components of RV mechanics including tissue Doppler s' (r = 0.40; p < 0.01) and TAPSE (r = 0.36; p < 0.01). When comparing echocardiographic and CMR structural parameters of the RV, we found that CMR RV volume was strongly related to echocardiographic measurements of RV end diastolic area (from the 4 chamber apical view) and with proximal parasternal short axis right ventricle outflow-dimension. Accordingly a regression model was derived from multiple regression analysis, which allows a more accurate estimate of CMR RV volume from echocardiography (r2 = 0.59, p < 0.001). Our study demonstrates a significant, although imperfect, correlation between echocardiographic and CMR RV functional and geometrical parameters. Combining echocardiographic measures of RV inflow and RV outflow, we deliver a simple formula to estimate CMR-RV volume, improving the echocardiographic accuracy in RV volume quantification.