Autograft Reoperation Following the Ross Procedure: Evolving Strategies and Future Perspectives.

Background: Pulmonary autograft failure remains a cause of reoperation following the Ross procedure. The aim of this study is to describe our evolving approach to autograft reoperations. Methods: Retrospective study of all patients who underwent a pulmonary autograft reoperation following a Ross procedure between June 1997 and July 2022. Results: Two-hundred and thirty-five Ross procedures were performed. Thirty-six patients (15%) plus one referral underwent an autograft reoperation at a median of 7.8 years (IQR 4.6-13.6). The main indication was: neoaortic root dilatation associated with mild/moderate (n = 12) or severe (n = 8) aortic regurgitation; isolated severe aortic regurgitation (n = 6); infective endocarditis (IE) (n = 8); and aortic root pseudoaneurysm with no history of IE (n = 3). The autograft was spared in 29 cases (78%): 9 patients (24%) underwent aortic valve repair or aortic root remodeling, 15 patients (40%) aortic root reimplantation, 5 patients neoaortic root stabilization with a Personalized External Aortic Root Support (PEARS) sleeve. There were no in-hospital deaths. At a median follow up of 37 months (IQR 8-105), all patients were alive, 30 (81%) were asymptomatic. Eight patients (22%) required nine further reoperations. Estimated freedom from further reoperation was 90%, 72%, and 72% at 12-, 36-, and 60-months. Conclusions: Autograft reoperations following the Ross procedure can be safely performed and do not affect overall survival in the early and mid-term. Valve-sparing autograft replacement is technically feasible but remains at risk of further interventions. Alternative strategies, such as the PEARS sleeve, are becoming increasingly available but requires validation in the long term.

An unmet need: arrhythmia detection by implantable loop recorder in the systemic right ventricle.

AIMS: Patients with systemic right ventricles are at high risk of sudden cardiac death. Arrhythmia is a significant risk factor. Routine Holter monitoring is opportunistic with poor adherence. The aim of this study was to determine if continuous rhythm monitoring with an implantable loop recorder (ILR) could allow early detection of clinically important arrhythmias. METHODS AND RESULTS: Implantable loop recorder implantation was offered to patients with atrial switch repair for transposition of the great arteries. Recordings were made with symptoms or, automatically for pauses, significant bradycardia or tachycardia and reviewed by the multi-disciplinary team. Twenty-four out of 36 eligible patients underwent ILR implantation with no complication. Forty-two per cent had preserved ventricular function, 75% were NYHA functional class I, 88% had low sudden cardiac death risk, 33% had previous intra-atrial re-entrant tachycardia (IART), and none had known conduction disease. Eighteen out of 24 (75%) patients made 52 recordings (52% automated) over 39.5 months (1.6-72.5). Thirty-two out of 52 (62%) recordings in 15/24 (63%) of the cohort were clinically significant and included sinus node disease (two patients), atrioventricular block (two patients), IART (seven patients), and IART with sinus node disease or atrioventricular block (four patients). Implantable loop recorder recordings prompted medication change in 11 patients [beta-blockers (n = 9), anti-coagulation (n = 5), and stopping anti-coagulation (n = 1)] and device therapy recommendation in seven patients [five pacemakers (three: atrioventricular block) and two defibrillators]. Two patients declined intervention; one suffered an arrhythmic death. Intra-atrial re-entrant tachycardia and clinically relevant conduction disease were detected in patients irrespective of sudden cardiac death risk. CONCLUSION: Continuous monitoring with an ILR in patients with systemic right ventricle following atrial switch detects clinically relevant arrhythmias that impact decision-making. In this cohort, clinically relevant arrhythmias did not correlate with sudden cardiac death risk.

Cardiovascular Complications of Down Syndrome: Scoping Review and Expert Consensus.

Cardiovascular disease is a leading cause of morbidity and mortality in individuals with Down syndrome. Congenital heart disease is the most common cardiovascular condition in this group, present in up to 50% of people with Down syndrome and contributing to poor outcomes. Additional factors contributing to cardiovascular outcomes include pulmonary hypertension; coexistent pulmonary, endocrine, and metabolic diseases; and risk factors for atherosclerotic disease. Moreover, disparities in the cardiovascular care of people with Down syndrome compared with the general population, which vary across different geographies and health care systems, further contribute to cardiovascular mortality; this issue is often overlooked by the wider medical community. This review focuses on the diagnosis, prevalence, and management of cardiovascular disease encountered in people with Down syndrome and summarizes available evidence in 10 key areas relating to Down syndrome and cardiac disease, from prenatal diagnosis to disparities in care in areas of differing resource availability. All specialists and nonspecialist clinicians providing care for people with Down syndrome should be aware of best clinical practice in all aspects of care of this distinct population.

Outcomes of the Ross procedure in young adults with previous aortic valve interventions.

OBJECTIVES: Contemporarily modified Ross procedure continues to deliver excellent outcomes and remains part of the treatment strategy for aortic valve disease in the young adult population. The aim of this study was to assess whether Ross procedure carried out as a second or subsequent intervention for aortic valve disease carries similar risk and long-term benefit, when compared to Ross procedure for the first-time aortic valve replacement. METHODS: A total of 158 patients aged 16-60 years from a single congenital cardiac centre between 1997 and 2020 were included. The sample was split into 2 subgroups, based on the history of previous aortic valve interventions prior to the Ross procedure. Primary outcomes were defined as survival and pulmonary autograft failure. Coarsened exact matching was used to balance for covariates. RESULTS: A total of 103 patients underwent primary Ross and 55 underwent secondary Ross with a mean follow-up of 7.8 years. Twenty-two patients underwent 28 reoperations during follow-up. Forty-nine well-matched pairs were obtained through matching. Freedom from pulmonary autograft failure at 10 years was 84.5% in the primary group vs 100% in the secondary group (P = 0.021). Five- and ten-year survival were identical, 97.5% in the primary group vs 95.6% in the secondary group (P = 0.53). Male sex and era were found to be predictors of neoaortic root dilatation. CONCLUSIONS: The lower incidence of graft failure seen in secondary Ross could justify a stepwise approach to aortic valve intervention. Ross procedure delivers excellent outcomes in the adult population with no difference in survival for primary or secondary Ross.

Gender differences in the assessment, decision-making and outcomes for ventricular assist devices and heart transplantation: An analysis from a UK transplant center.

PURPOSE: There are marked gender differences in all etiologies of advanced heart failure. We sought to determine whether there is evidence of gender-specific decision making for transplant assessments, and how gender effects outcomes. METHODS: Retrospective analysis of adult heart transplant assessments at a single UK center between April 2015 and March 2020. RESULTS: Females were 32% of referrals (N = 137 females, 285 males), with marked differences between diagnoses - 11% ischemic and 43% of adult congenital. Females were younger, shorter, weighed less, and had lower pulmonary pressures. Females were much less likely to receive a ventricular assist device (13%). Blood type "O" females were relatively more likely compared to males to receive a transplant (45%). Comparing males and females who received a ventricular assist device, both had similar levels of high pulmonary pressures, indicating consistent decision-making based on hemodynamics to implant a device. Overall survival was better for females (in noncongenital patients), and this was due to female patients who were not accepted for transplant or a ventricular assist device being more often "too well for transplant," rather than in males when they were more often "unsuitable." CONCLUSIONS: Marked gender differences exist at all stages of the heart transplant assessment pathway. Appropriate decision-making based on clinical grounds is shown with less transplants in male blood type "O"s and hemodynamic criteria for ventricular assist device implantation in both genders. Further studies are needed to determine if there is a wider community bias in advanced heart failure treatments for females.

Ventricular assist devices in transposition and failing systemic right ventricle: role of tricuspid valve replacement.

OBJECTIVES: Ventricular assist device (VAD) for systemic right ventricular (RV) failure patients post-atrial switch, for transposition of the great arteries (TGA), and those with congenitally corrected TGA has proven useful to reduce transpulmonary gradient and bridge-to-transplantation. The purpose of this study is to describe our experience of VAD in systemic RV failure and our move towards concomitant tricuspid valve replacement (TVR). METHODS: This is a single-centre retrospective study of consecutive adult patients receiving HeartWare VAD for systemic RV failure between 2010 and 2019. From 2017, concomitant TVR was performed routinely. Demographic, clinical variables and echocardiographic and haemodynamic measurements pre- and post-VAD implantation were recorded. Complications on support, heart transplantation and survival rates were described. RESULTS: Eighteen patients underwent VAD implantation. Moderate or severe systemic tricuspid regurgitation was present in 83.3% of patients, and subpulmonic left ventricular impairment in 88.9%. One-year survival was 72.2%. VAD implantation was technically feasible and successful in all but one. Post-VAD, transpulmonary gradient fell from 16 (15-22) to 10 (7-13) mmHg (P = 0.01). Patients with TVR (n = 6) also demonstrated a reduction in mean pulmonary and wedge pressures. Furthermore, subpulmonic left ventricular end-diastolic dimension (44.3 vs 39.6 mm; P = 0.03) and function improved in this group. After 1 year of support, 72.2% of patients were suitable for transplantation. CONCLUSIONS: VAD is an effective strategy as bridge-to-candidacy and bridge-to-transplantation in patients with end-stage systemic RV failure. Concomitant TVR at the time of implant is associated with better early haemodynamic and echocardiographic results post-VAD.

Use of Pulmonary Arterial Hypertension Therapies in Patients with a Fontan Circulation: Current Practice Across the United Kingdom.

Background The Fontan circulation is a successful operative strategy for abolishing cyanosis and chronic volume overload in patients with congenital heart disease with single ventricle physiology. "Fontan failure" is a major cause of poor quality of life and mortality in these patients. We assessed the number and clinical characteristics of adult patients with Fontan physiology receiving pulmonary arterial hypertension (PAH) therapies across specialist centers in the United Kingdom. Methods and Results We identified all adult patients with a Fontan-type circulation under active follow-up in 10 specialist congenital heart disease centers in England and Scotland between 2009 and 2019. Patients taking PAH therapies were matched to untreated patients. A survey of experts was also performed. Of 1538 patients with Fontan followed in specialist centers, only 76 (4.9%) received PAH therapies during follow-up. The vast majority (90.8%) were treated with a phosphodiesterase-5 inhibitor. In 33% of patients, PAH therapies were started after surgery or during hospital admission. In the matched cohort, treated patients were more likely to be significantly limited, have ascites, have a history of protein-losing enteropathy, or receive loop diuretics (P<0.0001 for all), also reflecting survey responses indicating that failing Fontan is an important treatment target. After a median of 12 months (11-15 months), functional class was more likely to improve in the treated group (P=0.01), with no other changes in clinical parameters or safety issues. Conclusions PAH therapies are used in adult patients with Fontan circulation followed in specialist centers, targeting individuals with advanced disease or complications. Follow-up suggests stabilization of the clinical status after 12 months of therapy.

Pulmonary arterial hypertension in adults with congenital heart disease: markers of disease severity, management of advanced heart failure and transplantation.

INTRODUCTION: Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is a progressive, life-limiting disease. AREAS COVERED: In this paper, we review the classification and pathophysiology of PAH-CHD, including the mechanisms of disease progression and multisystem effects of disease. We evaluate current strategies of risk stratification and the use of biological markers of disease severity, and review principles of management of PAH-CHD. The indications, timing, and the content of advanced heart failure assessment and transplant listing are discussed, along with a review of the types of transplant and other forms of available circulatory support in this group of patients. Finally, the integral role of advance care planning and palliative care is discussed. EXPERT OPINION/COMMENTARY: All patients with PAH-CHD should be followed up in expert centers, where they can receive appropriate risk assessment, PAH therapy, and supportive care. Referral for transplant assessment should be considered if there continue to be clinical high-risk features, persistent symptoms, or acute heart failure decompensation despite appropriate PAH specific therapy. Expert management of PAH-CHD patients, therefore, requires vigilance for these features, along with a close relationship with local advanced heart failure services and a working knowledge of listing criteria, which may disadvantage congenital heart disease patients.

Mechanical Circulatory Support for the Failing Sub-Aortic Right Ventricle in Adults.

Patients with ccTGA or d-TGA managed via atrial switch (Mustard or Senning operations) have biventricular circulations with a sub-aortic right ventricle (2V-RV). Other than in a tiny percentage of ccTGA patients, premature heart failure (HF) is common, driven by chronic RV dilatation and dysfunction and/or tricuspid regurgitation. These patients are different from the general HF population in that they are younger, more heterogeneous, are predisposed to pulmonary hypertension and present unique and complex surgical challenges. Despite their young age, they experience disproportionately poor access to advanced therapies and are often disqualified for transplant by pulmonary hypertension, HLA sensitization, program risk-tolerance and psychosocial issues. Mechanical support of the subaortic RV with ventricular assist device (subaortic RVAD, also known as SVAD), although technically challenging, can be an effective alternative to palliative care and offers high likelihood of bridging patients to heart transplant candidacy. In addition, temporary trans-catheter SVAD Impella support has been advantageous for stabilization of decompensated 2V-RV patients or as bridge to durable SVAD support. Improved awareness of and access to specialist ACHD-HF teams offering mechanical support (and transplantation) for 2V-RV patients is increasingly urgent for this aging population, and will improve options and outcomes for these patients as HF emerges.

Improving outcomes for transplantation in failing Fontan-what is the next target?

Objective: To identify the key contributors to postoperative mortality in patients undergoing orthotopic heart transplantation (OHT) for late Fontan failure. Methods: This retrospective review of failing Fontan patients who underwent OHT in our tertiary care center between 2007 and 2019 included adult patients with congenital heart disease and single ventricle physiology who were palliated with a Fontan circulation for >1 year. We excluded patients undergoing combined heart-liver transplantation. Results: The study cohort comprised 31 patients, including 18 males (58.1%), with a mean weight of 58.4 kg, median age at Fontan of 6.9 years (interquartile range [IQR], 2-38 years), and a median age at OHT of 27.1 years (IQR, 16.7-53.3). Almost all (93.5%) of the patients were in New York Heart Association class III-IV, and the majority (74.2%) were in Interagency Registry for Mechanically Assisted Circulatory Support class 3. Overall survival at 30 days, 1 year, and 5 years after OHT was 81%, 71%, and 67%, respectively. Major intraoperative bleeding was associated with increased mortality after OHT (odds ratio, 30; 95% confidence interval, 2.8-322; P = .002). Neither preoperative systemic ventricular function nor the development of primary graft dysfunction (PGD) was significantly associated with postoperative death. Nevertheless, PGD determined significant morbidity of this population. Conclusions: In our cohort, major intraoperative bleeding was the key factor associated with mortality after OHT for late Fontan failure. Novel strategies for the prevention and management of postoperative bleeding will improve outcomes in this group of patients.

Outcome following heart transplant assessment in adults with congenital heart disease.

OBJECTIVES: Adults with congenital heart disease (ACHD) are a growing group with end-stage heart failure. We aim to describe the outcomes of ACHD patients undergoing assessment for orthotopic heart transplant (OHT). METHODS: Case notes of consecutive ACHD patients (>16 years) assessed for OHT between 2000 and 2016 at our centre were reviewed. Decision and outcome were reported as of 2017. Data were analysed in three groups: systemic left ventricle (LV), systemic right ventricle (RV) and single ventricle (SV). RESULTS: 196 patients were assessed (31.8 years, 27% LV, 29% RV, 44% SV). 89 (45%) patients were listed for OHT and 67 (34%) were transplanted. 41 (21%) were unsuitable or too high risk and 36 (18%) were too well for listing. Conventional surgery was undertaken in 13 (7%) and ventricular assist device in 17 (9%) with 7 (4%) bridged to candidacy. Survival from assessment was 84.2% at 1 year and 69.7% at 5 years, with no difference between groups. Patients who were considered unsuitable for OHT (HR 11.199, p<0.001) and listed (HR 3.792, p=0.030) were more likely to die than those who were considered too well. Assessments increased over the study period. CONCLUSIONS: The number of ACHD patients assessed for OHT is increasing. A third are transplanted with a small number receiving conventional surgery. Those who are unsuitable have a poor prognosis.

Tissue oxygen saturation assessment of microvascular perfusion in adults with Fontan palliation and comparator groups using vascular optical spectrophotometry: a pilot study.

OBJECTIVE: The Fontan operation greatly improves survival for single ventricle congenital heart disease patients but creates a physiology that leads to long-term multi-organ dysfunction. A non-invasive screening tool that can identify impending decline is sought. The objective of this pilot study was to assess the microcirculation in Fontan-palliated patients by measuring tissue oxygen saturation (StO2) in superficial and deeper tissues. APPROACH: Three patient cohorts were studied: Fontan group (n = 8) and two patient control groups, liver disease group (n = 8) and tetralogy of Fallot group (n = 9). 22 healthy controls were also examined. Superficial and deeper StO2 was measured at the forearm, thenar eminence, index and ring fingers of both arms using the LEA O2C spectrophotometry device. MAIN RESULTS: Superficial StO2 was reduced in Fontan patients compared to healthy controls (p  = 0.002) and tetralogy patients (p  = 0.016), but not compared to the liver group (p  = 0.313). Deeper StO2 was similar between groups (p  = 0.112). The gap between deeper and superficial StO2 was raised in Fontan patients compared to healthy controls (p  = 0.001) and tetralogy patients (p  = 0.037), but not compared to the liver group (p  = 0.504). There was no clinically relevant difference in StO2 between the left and right arms, and the variation in StO2 according to measurement site was similar between the four groups. SIGNIFICANCE: Vascular optical spectrophotometry is a feasible non-invasive measure of micro-circulatory function that can easily be performed in the clinic setting and may have utility in patients with Fontan circulations. Further, we provide important normal range data in the healthy control population which can be used to design future studies.

Clinical features and prognosis of patients with isolated severe aortic stenosis and valve area less than 1.0 cm2.

OBJECTIVE: Current guidelines define severe aortic stenosis (AS) as an aortic valve area (AVA)≤1.0 cm2, but some authors have suggested that the AVA cut-off be decreased to 0.8 cm2. The aim of this study was, therefore, to better describe the clinical features and prognosis of patients with an AVA of 0.8-0.99 cm2. METHODS: Patients with isolated, severe AS and ejection fraction ≥55% with an AVA of 0.8-0.99 cm2 (n=105) were compared with those with an AVA<0.8 cm2 (n=155) and 1.0-1.3 cm2 (n=81). The endpoint of this study was a combination of death from any cause or aortic valve replacement at or before 3 years. RESULTS: Patients with an AVA of 0.8-0.99 cm2 group comprised predominantly normal-flow, low-gradient (NFLG) AS, while high gradients and low flow were more often observed with an AVA<0.8 cm2. The frequency of symptoms was not significantly different between an AVA of 0.8-0.99 cm2 and 1.0-1.3 cm2. The combined endpoint was achieved in 71%, 52% and 21% of patients with an AVA of 0.8 cm2, 0.8-0.99 cm2and 1.0-1.3 cm2, respectively (p<0.001). Among patients with an AVA of 0.8-0.99 cm2, NFLG AS was associated with a lower hazard (HR=0.40, 95% CI 0.23 to 0.68, p=0.001) of achieving the combined endpoint with outcomes similar to moderate AS in the first 1.5 years of follow-up. Patients with high-gradient or low-flow AS with an AVA of 0.8-0.99 cm2 had outcomes similar to those with an AVA<0.8 cm2. The sensitivity for the combined endpoint was 61% for an AVA cut-off of 0.8 cm2 and 91% for a cut-off of 1.0 cm2. CONCLUSIONS: The outcomes of patients with AS with an AVA of 0.8-0.99 cm2 are variable and are more precisely defined by flow-gradient status. Our findings support the current AVA cut-off of 1.0 cm2.

A propensity score-adjusted analysis of clinical outcomes after pulmonary valve replacement in tetralogy of Fallot.

OBJECTIVE: To determine the association of pulmonary valve replacement (PVR) with death and sustained ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTOF). METHODS: Subjects with rTOF and cardiac magnetic resonance from an international registry were included. A PVR propensity score was created to adjust for baseline differences. PVR consensus criteria were predefined as pulmonary regurgitation >25% and ≥2 of the following criteria: right ventricular (RV) end-diastolic volume >160 mL/m2, RV end-systolic volume >80 mL/m2, RV ejection fraction (EF) <47%, left ventricular EF <55% and QRS duration >160 ms. The primary outcome included (aborted) death and sustained VT. The secondary outcome included heart failure, non-sustained VT and sustained supraventricular tachycardia. RESULTS: In 977 rTOF subjects (age 26±15 years, 45% PVR, follow-up 5.3±3.1 years), the primary and secondary outcomes occurred in 41 and 88 subjects, respectively. The HR for subjects with versus without PVR (time-varying covariate) was 0.65 (95% CI 0.31 to 1.36; P=0.25) for the primary outcome and 1.43 (95% CI 0.83 to 2.46; P=0.19) for the secondary outcome after adjusting for propensity and other factors. In subjects (n=426) not meeting consensus criteria, the HR for subjects with (n=132) versus without (n=294) PVR was 2.53 (95% CI 0.79 to 8.06; P=0.12) for the primary outcome and 2.31 (95% CI 1.07 to 4.97; P=0.03) for the secondary outcome. CONCLUSION: In this large multicentre rTOF cohort, PVR was not associated with a reduced rate of death and sustained VT at an average follow-up of 5.3 years. Additionally, there were more events after PVR compared with no PVR in subjects not meeting consensus criteria.

Paediatric-onset coronary artery anomalies in pregnancy: a single-centre experience and systematic literature review.

OBJECTIVES: Individuals with childhood-onset coronary artery anomalies are at increased risk of lifelong complications. Although pregnancy is thought to confer additional risk, a few data are available regarding outcomes in this group of women. We sought to define outcomes of pregnancy in this unique population. METHODS: We performed a retrospective survey of women with paediatric-onset coronary anomalies and pregnancy in our institution, combined with a systematic review of published cases. We defined paediatric-onset coronary artery anomalies as congenital coronary anomalies and inflammatory arteriopathies of childhood that cause coronary aneurysms. Major cardiovascular events were defined as pulmonary oedema, sustained arrhythmia requiring treatment, stroke, myocardial infarction, cardiac arrest, or death. RESULTS: A total of 25 surveys were mailed, and 20 were returned (80% response rate). We included 46 articles from the literature, which described cardiovascular outcomes in 82 women (138 pregnancies). These data were amalgamated for a total of 102 women and 194 pregnancies; 59% of women were known to have paediatric-onset coronary artery anomalies before pregnancy. In 23%, the anomaly was unmasked during or shortly after pregnancy. The remainder, 18%, was diagnosed later in life. Major cardiovascular events occurred in 14 women (14%) and included heart failure (n=5, 5%), myocardial infarction (n=7, 7%), maternal death (n=2, 2%), cardiac arrest secondary to ventricular fibrillation (n=1, 1%), and stroke (n=1, 1%). The majority of maternal events (13/14, 93%) occurred in women with no previous diagnosis of coronary disease. CONCLUSIONS: Women with paediatric-onset coronary artery anomalies have a 14% risk of adverse cardiovascular events in pregnancy, indicating the need for careful assessment and close follow-up. Prospective, multicentre studies are required to better define risk and predictors of complications during pregnancy.

Differential left ventricular outflow tract remodeling and dynamics in aortic stenosis.

BACKGROUND: Left ventricular outflow tract (LVOT) geometry is variable and often elliptical, which can affect aortic valve area calculation in patients with aortic stenosis (AS). Specific differences in LVOT geometry and dynamics between patients with AS and normal control subjects have not been described. The aim of this study was to test the hypothesis that differences in LVOT geometry in patients with AS might relate to variable LVOT remodeling and stiffness relative to normal control subjects. METHODS: In 54 patients with severe AS and 33 control subjects without AS, LVOT geometry, dynamics, remodeling, and stiffness were assessed by three-dimensional transesophageal echocardiography. LVOT stiffness was measured by calculating the distensibility coefficient, defined as the percentage change in LVOT area relative to change in left ventricular pressure. LVOT remodeling was assessed by measuring the posterior LVOT wall thickness. Multivariate linear regression analysis was used to determine independent associations with peak systolic LVOT ellipticity. LVOT area by three-dimensional transesophageal echocardiographic planimetry was compared with areas obtained assuming circular or elliptical geometry. RESULTS: At end-diastole, LVOT geometry was similar between patients with AS and normal control subjects. In patients with AS, however, the percentage change in cross-sectional area (7.5% vs 14.7%, P < .001) from end-diastole to peak systole was lower compared with normal control subjects, while peak systolic ellipticity index was higher in patients with AS (1.18 vs 1.08, P < .001). Compared with control subjects, patients with AS had lower distensibility coefficients (4.7 ± 1.9 × 10(4) vs 12.5 ± 5.3 × 10(4) mm Hg(-1), P < .001) and higher posterior LVOT wall thickness (3.5 ± 0.8 vs 2.3 ± 0.5 mm, P < .001). In multivariate analysis, posterior LVOT wall thickness and distensibility coefficient were independently associated with peak systolic LVOT ellipticity index. LVOT area underestimation by transthoracic echocardiography was higher in patients with AS when assuming circular geometry (20% vs 12%, P = .001). CONCLUSIONS: The LVOT is less distensible and undergoes remodeling in severe AS. These changes lead to greater peak systolic ellipticity and greater LVOT cross-sectional area underestimation relative to normal control subjects. These findings have important implications for the assessment of AS severity.

Percutaneous pulmonary valve implantation for free pulmonary regurgitation following conduit-free surgery of the right ventricular outflow tract.

INTRODUCTION: Pulmonary regurgitation (PR) following surgery of the right ventricular outflow tract (RVOT) is not innocent and leads to significant right heart dysfunction over time. Recent studies have demonstrated that percutaneous valves can be implanted in conduit free outflow tracts with good outcomes. OBJECTIVES: To evaluate in patients with severe PR--anticipated to require future pulmonary valve replacement--the feasibility and safety of pre-stenting dilated non-stenotic patched conduit-free right ventricular outflow tracts before excessive dilation occurs, followed by percutaneous pulmonary valve implantation (PPVI). PATIENTS AND METHODS: Twenty seven patients were evaluated, but only 23 were deemed suitable based on the presence of an adequate retention zone ≤ 24 mm defined by semi-compliant balloon interrogation of the RVOT. A 2 step procedure was performed: first the landing zone was prepared by deploying a bare stent, followed 2 months later by valve implantation. RESULTS: RVOT pre-stenting with an open cell bare metal stent (Andrastent XXL range) was performed at a median age of 13.0 years (range: 6.0-44.9) with a median weight of 44.3 kg (range: 20.0-88.0). Ninety six percent (22/23) of patients proceeded to PPVI a median of 2.4 months (range: 1.4-3.4) after initial pre-stent placement. Twenty one Melody valves and one 26 mm Edwards SAPIEN™ valve were implanted. Complications consisted of embolization of prestent (n = 1), scrunching (n = 4) and mild stent dislocation (n = 2). During follow-up, no stent fractures were observed and right ventricular dimensions decreased significantly. CONCLUSIONS: Post-surgical conduit-free non-stenotic RVOT with free pulmonary regurgitation can be treated percutaneously with a valved stent if anatomical (predominantly size) criteria are met. In experienced hands, the technique is feasible with low morbidity.