National In-Hospital Outcomes of Mechanical Mitral Valve Replacement in the Pediatric Population.

Background: National data about the outcomes of children undergoing mechanical mitral valve replacement (m-MVR) are scarce. Methods: A retrospective review of hospitalizations from the Kids' Inpatient Database was performed for patients ≤18 years of age in the United States. A total of 500 patients underwent m-MVR in 2009, 2012, 2016, and 2019. Patients with single ventricle physiology were excluded (n = 13). These patients were categorized into three groups according to age: neonates (<1 month, n = 20), infants (1-12 months, n = 76 patients), and children (1-18 years, n = 404). Outcomes were compared between the three groups. Results: The proportion of m-MVR involving children undergoing MV procedures (repair and replacement) has increased from 17.3% in 2009 to 30.8% in 2019 (Ptrend < .01). History of cardiac surgery was present in 256 patients (51.2%). Concomitant procedures were performed in 119 patients (23.8%). Intra- or postoperative extracorporeal membrane oxygenation was required in 19 patients (3.8%). The overall in-hospital mortality was 4.8% and was significantly higher in neonates and infants compared with older children (10% vs 11.8% vs 3.2%, P = .003). The length of hospital stay was longer in the neonatal group (median, 57 days, interquartile range, [24.8-90] vs 29.5 days [15.5-61] vs 10 days [7-18], P < .01). Nonhome discharges were more common in neonates and infants (40% vs 36.8% vs 13.1%, P < .01). Conclusion: Mechanical mitral valve replacement is increasingly performed over time with acceptable in-hospital morbidity and mortality, especially in older children and adolescents. Neonates and infants are associated with worse hospital survival, prolonged hospitalization, and significant rates of nonhome discharges.

Outcomes of Tricuspid Valve Repair With Artificial Neochordae in Pediatric and Adult Patients.

BACKGROUND: There are sparse data on outcomes after expanded polytetrafluoroethylene artificial neochordae (ePTFE-AN) for tricuspid valve (TV) repair. We evaluated outcomes after TV repair with ePTFE-AN in both pediatric and adult patients. METHODS: We analyzed clinical data of 87 consecutive patients who underwent ePTFE-AN implantation at the time of TV repair from 1998 to 2020. Patients were categorized into pediatric and adult groups. RESULTS: There were 29 pediatric (33.3%) and 58 adult (66.7%) patients. The most common etiology of tricuspid regurgitation (TR) was congenital (pediatrics: 86.2% [25 of 29]; adults: 39.7% [23 of 59]). The median number of pairs of ePTFE-AN implanted was 2 (interquartile range [IQR], 2-5 pairs) for pediatric and 3 (IQR, 2-4 pairs) for adult patients. There was no early death. Three adult patients (5.2%) required early TV reoperation, and 4 patients (1 pediatric, 3 adults) underwent late TV reintervention. Etiology of TR was congenital in 4 of the 6 adults who required TV reintervention. The 3-year cumulative risk of TV reintervention was 0.0% for pediatric and 7.3% (95% CI, 0.4%-14.2%) for adult patients. There was significant improvement in TR grade after TV repair at dismissal and at the latest echocardiographic follow-up in each group (P < .001). Severe TR developed in 1 pediatric patient and 7 adult patients during follow-up, and 6 (1 pediatric, 5 adults) of them underwent TV reoperation. CONCLUSIONS: ePTFE-AN implantation in the TV position can be performed safely and effectively with no early death. In adult patients with congenital TR, patient selection is critical to achieve a durable outcome after TV repair.

Management of Isolated, Congenital Anterior Mitral Valve Cleft.

Background: Isolated anterior mitral valve clefts (MVC) are rare congenital heart defects, and data are limited regarding the natural history and surgical outcomes for such isolated MVCs. Methods: We conducted a retrospective review of patients with congenital MVC who were evaluated at Mayo Clinic in Rochester, Minnesota between 1993 and 2020. Patients were separated into two cohorts: those who underwent surgical repair of the MVC and those who had not yet undergone repair. Baseline and postoperative clinical and echocardiographic data were analyzed. Results: Fourteen patients were included in the nonsurgical cohort and eight patients in the surgical cohort. Surgical repair was via primary median sternotomy (n = 6) or robot-assisted, minimally invasive (n = 2). All cleft repairs were performed by simple suture closure. Intraoperative evaluation of the clefts did not reveal additional structural factors that could account for the mitral regurgitation (MR). At latest follow-up of the surgical cohort, the median grade of MR was 1 (range 0-1), and median left ventricular ejection fraction was 65% (IQR 59%-67%), both similar to the immediate postoperative result. At latest follow-up, all patients in the nonsurgical cohort were NYHA Class 1, and median MR grade was 1. All patients were asymptomatic (NYHA Class 1). Conclusions: Our findings corroborate prior reports that MVC repair is safe and successful and is followed by a low rate of recurrent mitral valve dysfunction. Durable surgical repair of isolated, congenital MVC can be performed safely in select patients. The decision to intervene should be based on the severity of mitral regurgitation and patient symptoms rather than the presence of the MVC alone.

What Factors Should Be Considered to Improve Outcome of Mechanical Mitral Valve Replacement in Children?

OBJECTIVE: To identify risk factors for pediatric mechanical mitral valve replacement (mMVR) to improve management in this challenging population. METHODS: From 1993 to 2019, 93 children underwent 119 mMVR operations (median age, 8.8 years [interquartile range [IQR]: 2.1-13.3], 54.6% females) at our institution. Twenty-six (21.8%) patients underwent mMVR at ≤2 years and 93 (78.2%) patients underwent mMVR at >2 years. Median follow-up duration was 7.6 years [IQR: 3.2-12.4]. RESULTS: Early mortality was 9.7%, but decreased with time and was 0% in the most recent era (13.9% from 1993 to 2000, 7.3% from 2001 to 2010, 0% from 2011 to 2019, P = .04). It was higher in patients ≤2 years compared to patients >2 years (26.9% vs 2.2%, P < .01). On multivariable analysis for mitral valve reoperation, valve size <23 mm was significant with a hazard ratio of 5.38 (4.87-19.47, P = .01);. Perioperative stroke occurred in 1% and permanent pacemaker was necessary in 12%. Freedom from mitral valve reoperation was higher in patients >2 years and those with a prosthesis ≥23 mm. Median time to reoperation was 7 years (IQR: 4.5-9.1) in patients >2 years and 3.5 years (IQR: 0.6-7.1) in patients ≤2 years (P = .0511), but was similar between prosthesis sizes (P = .6). During follow-up period (median 7.6 years [IQR: 3.2-12.4], stroke occurred in 10%, prosthetic valve thrombosis requiring reoperation in 4%, endocarditis in 3%, and bleeding in 1%. CONCLUSION: Early and late outcomes of mMVR in children are improved when performed at age >2 years and with prosthesis size ≥23 mm. These factors should be considered in the timing of mMVR.

Radiation dose reduction for 3D angiography images in pediatric and congenital cardiology.

OBJECTIVES: The purpose of this study was to investigate the influence of simulated reduced-dose three-dimensional angiography (3DA) on the accuracy and precision of linear measurements derived from 3DA datasets. BACKGROUND: Three-dimensional angiography is performed during X-ray guided interventional procedures to aid diagnosis and inform treatment strategies for children and adults with congenital heart disease. However, 3DA contributes substantially to patient radiation dose and may lead to an increased radiation-induced cancer risk. METHODS: Reduced-dose patient 3DA images were simulated by adding quantum noise to the 2D projection angiograms, then reconstructing the projection angiograms into the 3DA dataset. Dose reduction in the range 33-72% was simulated. Five observers performed 46 vessel diameter measurements along prespecified axes within 23 vessel segments from 11 patient 3DA datasets. Statistical tests were performed to assess the influence of radiation dose reduction on the accuracy and precision of vessel diameter measurements. RESULTS: Vessel diameter measurements were in the range 5.9- 22.7 mm. Considering all vessel segments and observers, the influence of dose level on the accuracy of diameter measurements was in the range 0.02 - 0.15 mm (p .05-.8). Interobserver variability increased modestly with vessel diameter, but was not influence by dose level (p = .52). The statistical test for observer recall bias was negative (p = .51). CONCLUSIONS: Simulated dose reduction up to 72% did not affect the accuracy or precision of the diameter measurements acquired from 3DA images. These findings may embolden 3DA radiation dose reduction for pediatric and congenital heart disease patients.

Left Ventricular Remodeling After Transcatheter Versus Surgical Therapy in Adults With Coarctation of Aorta.

OBJECTIVES: The purpose of this retrospective cohort study was to compare remodeling of left ventricular (LV) structure and function after transcatheter stent therapy with remodeling of LV structure and function after surgical therapy for COA. BACKGROUND: Transcatheter stent therapy is as effective as surgery in producing acute hemodynamic improvement in patients with coarctation of aorta (COA). However, LV remodeling after transcatheter COA intervention has not been systematically investigated. METHODS: LV remodeling was assessed at 1, 3, and 5 years post-intervention by using LV mass index (LVMI), LV end-diastolic dimension, LV ejection fraction, LV global longitudinal strain (LVGLS), LV mitral annular tissue Doppler early velocity (LVe'), and ratio of mitral inflow pulsed wave Doppler early velocity and e' (E/e') ratio. RESULTS: There were 44 patients in the transcatheter group and 128 patients in the surgical group. Compared to the surgical group, the transcatheter group had less regression of LVMI (-4.6; 95% confidence interval [CI]: -5.5 to -3.7 vs. -7.3; 95% CI: -8.4 to -6.6 g/m2; p < 0.001), less improvement in LVGLS (2.1; 95% CI: 1.8 to 2.4 vs. 2.9; 95% CI: 2.6 to 3.2%; p = 0.024), and in e' (1.0 ; 95% CI: 0.7 to 1.2 vs. 1.5 ; 95% CI: 1.3 to 1.7 cm/s; p = 0.009) at 5 years post-intervention. Exploratory analysis showed a correlation between change in LVMI and LVGLS, and between change in LVMI and mitral annular tissue Doppler early velocity (e'), and this correlations were independent of the type of intervention received. CONCLUSIONS: Transcatheter stent therapy was associated with less remodeling of LV structure and function during mid-term follow-up. As transcatheter stent therapy becomes more widely used in the adult COA population, there is a need for ongoing clinical monitoring to determine if these observed differences in LV remodeling translate to differences in clinical outcomes.

Exercise Capacity After Repair of Ebstein Anomaly in Adults.

Repair of Ebstein anomaly has evolved over the last decade, and timing of repair remains variable. There have been no studies of exercise or functional capacity in patients who have had tricuspid valve surgery for Ebstein anomaly in adulthood. We aimed to compare exercise capacity before and after tricuspid valve repair or replacement for Ebstein anomaly in adults at Mayo Clinic. We performed a retrospective chart review of all patients with Ebstein anomaly who underwent tricuspid valve surgery at Mayo Clinic between June 2007 and January 2015. We compared pre- and postoperative echocardiograms, exercise tests, and clinic visits. Tricuspid valve surgery was done for 322 patients, and 32 patients met criteria of native tricuspid valve repair or replacement at age 18 or older and had maximal pre- and postoperative exercise tests. Nineteen patients had valve repair, and 13 had valve replacement. Surgery for Ebstein anomaly resulted in significant reduction in tricuspid regurgitation and right ventricular size. There was a significant improvement in NYHA functional class after surgery; however, there was no significant improvement in functional aerobic capacity (FAC), metabolic equivalents (METs), exercise time, or [Formula: see text] after surgery. Patients who had an atrial shunt closed during surgery had improved minimum blood oxygen saturations during exercise, though no improvement in exercise capacity. In our cohort, patients who had tricuspid valve repair or replacement for Ebstein anomaly reported an improvement in functional capacity; however, this did not reflect improvement in measured exercise capacity, despite excellent surgical results by echocardiography.

Innovative 2-Step Management Strategy Utilizing EXIT Procedure for a Fetus With Hypoplastic Left Heart Syndrome and Intact Atrial Septum.

Hypoplastic left heart syndrome (HLHS) with intact atrial septum (HLHS-IAS) carries a high risk of mortality and affects about 6% of all patients with HLHS. Fetal interventions, postnatal transcatheter interventions, and postnatal surgical resection have all been used, but the mortality risk continues to be high in this subgroup of patients. We describe a novel, sequential approach to manage HLHS-IAS and progressive fetal hydrops. A 28-year-old, gravida 4 para 2 mother was referred to Mayo Clinic for fetal HLHS. Fetal echocardiography at 28 weeks of gestation demonstrated HLHS-IAS with progressive fetal hydrops. The atrial septum was thick and muscular with no interatrial communication. Ultrasound-guided fetal atrial septostomy was performed with successful creation of a small atrial communication. However, fetal echocardiogram at 33 weeks of gestation showed recurrence of a pleural effusion and restriction of the atrial septum. We proceeded with an Ex uteroIntrapartum Treatment (EXIT) delivery and open atrial septectomy. This was performed successfully, and the infant was stabilized in the intensive care unit. The infant required venoarterial extracorporeal membrane oxygenator support on day of life 1. The patient later developed hemorrhagic complications, leading to his demise on day of life 9. This is the first reported case of an EXIT procedure and open atrial septectomy performed without cardiopulmonary bypass for an open-heart operation and provides a promising alternative strategy for the management of HLHS-IAS in select cases.

Fate of the Fontan connection: Mechanisms of stenosis and management.

BACKGROUND: Stenosis of the venous connections and conduits is a well-known late complication of the Fontan procedure. Currently, data on the outcomes of percutaneous intervention for the treatment of extra- or intracardiac conduits and lateral tunnel baffles obstruction are limited. In an attempt to better define the nature and severity of the stenosis and the results of catheter interventional management, we reviewed Fontan patients with obstructed extra- or intracardiac conduits and lateral tunnel baffles. METHODS: Retrospective review of all Fontan patients who had cardiac catheterization from January 2002 to October 2018 was performed. Hemodynamic and angiographic data that assessed extra- or intracardiac conduit, or lateral tunnel baffle obstruction/stenosis were evaluated. RESULTS: Twenty patients underwent catheter intervention because of conduit stenosis, including calcified homografts, stenotic Gore-Tex conduits and obstructed lateral tunnels. Six other patients had Fontan obstruction but were referred for surgical revision. After stenting, there was a significant reduction in the connection gradient [2.0 mm Hg (IQR 2; 3) vs 0 mm Hg (IQR 0; 1), P < .0001]. Fontan conduit/connection diameter increased [10.5 mm (IQR 9; 12) vs 18 mm (IQR 14.9; 18); P < .0001] and New York Heart Association class [III (IQR II; III) vs I (IQR II; III); P = .03) with stent placement. CONCLUSIONS: We demonstrated the hemodynamics and angiographic subtypes of conduit stenosis in patients after Fontan, We showed that calcified homografts, stenotic Gore-Tex conduits and lateral tunnels pathways can be safely and effectively stented to eliminate obstruction. Percutaneous stenting is associated with a decrease in connection gradients and improvement in functional capacity.

Outcomes of Transcatheter Tricuspid Valve-in-Valve Implantation in Patients With Ebstein Anomaly.

We sought to describe the acute results and short- to medium-term durability of transcatheter tricuspid valve-in-valve (TVIV) implantation within surgical bioprostheses among patients with Ebstein anomaly (EA). Cases were identified from a voluntary, multicenter, international registry of 29 institutions that perform TVIV. Demographic, clinical, procedural, and follow-up data were analyzed. Eighty-one patients with EA underwent TVIV from 2008 to 2016. Thirty-four patients (42%) were New York Heart Association (NYHA) class 3/4 at time of TVIV. The most common indication for TVIV was the presence of moderate or severe tricuspid regurgitation (40%). Most patients received a Melody valve (64%). TVIV was ultimately successful in all patients, and there was no procedural mortality. Four patients (5%) developed acute valve thrombosis, 4 patients (5%) developed endocarditis, and 9 patients (11%) developed valve dysfunction not related to thrombosis or endocarditis. Eight patients (10%) underwent reintervention (2 transcatheter, 6 surgical) due to thrombosis (3), endocarditis (2), other valve dysfunction (2), and patient-prosthesis mismatch without valve dysfunction (1). Among 69 patients who were alive without reintervention at latest follow-up, 96% of those with NYHA status reported were class 1/2, a significant improvement from baseline (62% NYHA class 1/2, p <0.001). In conclusion, transcatheter TVIV offers a low-risk, minimally invasive alternative to surgical tricuspid valve re-replacement in patients with EA and a failing tricuspid valve bioprosthesis.

Ultrasound guided percutaneous common carotid artery access in piglets for intracoronary stem cell infusion.

In pigs, the deep location of the common carotid artery and overlying sternomastoideus muscle in the neck has led to the recommendation for a surgical cutdown for common carotid access, as opposed to minimally invasive techniques for vascular access. We sought to determine if direct percutaneous common carotid artery access in piglets is attainable. Seventeen piglets were anesthetized and intubated. Under two-dimensional and color flow Doppler ultrasound guidance, a 21 gauge needle was utilized to access the right common carotid artery. Following arterial puncture, the Seldinger technique was applied to place a 4 or 5 French introducer. Upon completion of cardiac catheterization with intracoronary stem cell infusion the introducer was removed and manual pressure was applied to prevent hematoma development. Successful access with an introducer was achieved in all 17 piglets. The average weight was 8.5 ± 1.7 kg. One piglet developed a hematoma with hemorrhaging from the catheterization site and was euthanized. This piglet was given bivalirudin for the procedure. After this incident, subsequent piglets were not given anticoagulation and no other complications occurred. Ultrasound guided percutaneous common carotid artery access in piglets is attainable in a safe, reliable, and reproducible manner when performed by microvascular experts.

Acute and midterm results following perventricular device closure of muscular ventricular septal defects: A multicenter PICES investigation.

OBJECTIVES: To describe acute and mid-term results of hybrid perventricular device closure of muscular ventricular septal defects (mVSDs). BACKGROUND: Perventricular device closure of mVSDs can mitigate technical limitations of percutaneous closure and need for cardiopulmonary bypass or ventriculotomy with a surgical approach. METHODS: This is a multicenter retrospective cohort study of patients undergoing hybrid perventricular mVSD device closure from 1/2004 to 1/2014. Procedural details, adverse events, outcomes, and follow-up data were collected. Patients were divided into two groups: (1) simple (mVSD closure alone) and (2) complex (mVSD closure with concomitant cardiac surgery). RESULTS: Forty-seven patients (60% female) underwent perventricular mVSD device closure at a median age of 5.2 months (IQR 1.8-8.9) and weight of 5.1 kg (IQR 4.0-6.9). Procedural success was 91% [100% (n = 22) simple and 84% (n = 21/25) complex]. Adverse events occurred in 19% (9/47) [9% (2/22) simple and 28% (7/25) complex]. Hospital length of stay (LOS) was shorter in the simple vs. complex group (4 vs. 14 days, P < 0.01). At mid-term follow-up of 19.2 months (IQR 2.3-43) 90% of pts had complete mVSD closure; none developed late heart block, increased atrioventricular (AV) valve insufficiency or ventricular dysfunction. CONCLUSIONS: Perventricular device closure of simple mVSD was associated with a high rate of procedural success, few adverse events, and short hospital LOS. Procedural adverse events were associated with the presence of concomitant complex surgery. Residual mVSD, AV valve insufficiency, or ventricular dysfunction were uncommon at mid-term follow-up. © 2017 Wiley Periodicals, Inc.

Intravascular and hybrid intraoperative stent placement for baffle obstruction in transposition of the great arteries after atrial switch.

OBJECTIVES: To report our experience with intravascular and hybrid intra-operative stent placement for baffle obstruction in patients with complete transposition of the great arteries (TGA) after the atrial switch (Mustard/Senning) operation. BACKGROUND: Venous baffle obstruction is a challenging complication after atrial switch operation in patients with TGA. Traditional treatment options include intravascular stenting or surgery. METHODS: A retrospective analysis of Mayo Clinic's electronic medical record was completed to identify consecutive pediatric and adult patients with TGA after atrial switch who underwent baffle stent implantation from 1994 to 2015. RESULTS: Overall, 64 patients were referred for cardiac catheterization, in whom 47 (73%) were noted to have hemodynamic and angiographic evidence of baffle obstruction. A total of 20 patients mean age 33 (range: 8-46) years old underwent stent implantation of baffle stenosis at a mean of 33 (range: 7.5-45) years after initial atrial switch operation (Mustard, n = 19; Senning, n = 1). Overall, 27 baffles were stented in 20 patients via the following approaches: intravascular (17); hybrid surgical (3); staged intravascular & hybrid (2). Sites of stent placement were: superior vena cava (SVC) (13); inferior vena cava (IVC) (9); pulmonary venous baffle (5). Three patients had stent placement in the SVC and IVC baffles during the same procedure. Procedural adverse events occurred in 2/22 cases (9%) including creation of unintentional baffle leak (n = 1) and stent migration (n = 1). There was no procedure-related mortality. At follow-up (median 2, range 0.02-10 years), significantly improved NYHA class and mean Doppler baffle gradient were demonstrated (P < 0.05). Mild baffle re-stenosis (mean Doppler gradient; 2-3 mmHg) occurred in two patients who have not required re-intervention. Trivial baffle leak was noted in four patients. Baffle re-intervention was only occurred in one patient. One patient with pre-procedural Class IV symptoms died 3.5 months after stent implantation. CONCLUSIONS: This study is the largest reported experience of intravascular and intra-operative hybrid stent placement for patients with TGA after atrial switch. Transcatheter and minimally invasive hybrid intraoperative surgical stent placement are an effective strategy for relief of systemic and pulmonary venous baffle obstruction. © 2016 Wiley Periodicals, Inc.

Minimally invasive video-assisted surgical closure of atrial septal defects: a safe approach.

OBJECTIVE: To compare the safety and effectiveness of video-assisted thoracic surgery (VATS) versus conventional median sternotomy (open) in the repair of secundum atrial septal defect (ASD) or patent foramen ovale (PFO). DESIGN: Among 415 consecutive patients undergoing open or VATS ASD/PFO closure between 1993 and October 2012, 153 patients were compared using 2:1 frequency matching (n=102 open vs 51 VATS). Matching variables include age, gender, body surface area, past medical history of neurologic events, and need of patch closure. Median age was 43 years (3-71 years), and 67% were female. RESULTS: There were no early deaths in either group. There were no conversions to open sternotomy. Although mean cross-clamp time (14.5±7.6 vs 26.3±13.2 minutes, P<.001) and bypass time (31.7±13.8 vs 60.9±20.9 minutes, P<.001) were longer in the VATS group, patients who underwent VATS had shorter postoperative ventilation time (7.5±6.4 vs 4.4±2.8 hours, P=.03) with 62.7% extubated in the operating room, along with shorter intensive care unit stay (26.7±10.8 vs 19.1±9.9 hours, P<.001) and hospital stay (5.2±1.9 vs 3.5±0.9 days, P<.001). At early follow-up (mean 1.5 years, maximum 4.2 years), there was no difference in need for reintervention. Of the 27 patients who underwent VATS ASD/PFO closure for a neurologic event, none had a recurrence. CONCLUSION: The use of VATS provides a safe, equally effective alternative to conventional sternotomy for ASD/PFO closure, using a less invasive approach.

A stepwise model for delivering medical humanitarian aid requiring complex interventions.

OBJECTIVES: Cardiothoracic surgeons and practitioners of cardiovascular medicine have a long history of humanitarian aid. Although this is worthwhile at multiple levels and occasionally described in some detail, few efforts have a proven algorithm with demonstrable outcomes that suggest effective educational methodology or clinical results approaching accepted standards in developed countries. METHODS: Our report provides a stepwise approach to developing highly successful self-sustainable, replicable, and scalable humanitarian congenital cardiac surgical programs, and provides data to allow insight into the efficacy of our model. RESULTS: This program model has evolved over 25 years, during which it has been replicated several times and scaled throughout a vast and populous country. Since 1989, Russia has undergone considerable social, political, and economic changes. Our program model proved successful throughout this time despite dynamic social, political, and medical landscapes. CONCLUSIONS: The positive results of our program model indicate that these methodologies may be helpful to others attempting to address the worldwide shortage of cardiovascular care and particularly the complex interventions required in the management of congenital cardiovascular disease.

Septum primum atrial septal defect in an infant with hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) is a form of congenital heart disease characterized by severe underdevelopment of the left heart, leading to inadequate systemic blood flow. Several different atrial septal morphologies are observed in HLHS, most commonly a secundum atrial septal defect, patent foramen ovale, intact septum, and leftward displacement of the superior attachment of the septum primum. It has been postulated that atrial septal development is associated with the development of the left heart. We present a case of a newborn infant with HLHS and the unusual finding of a primum ASD.