Jeffery Meadows

Use and Performance of the Melody Transcatheter Pulmonary Valve in Native and Postsurgical, Nonconduit Right Ventricular Outflow Tracts

Background—Melody Transcatheter Pulmonary Valve (TPV) replacement therapy represents an important advance in congenital cardiovascular interventions. The off-label extension of the Melody TPV to patients with nonconduit outflow tracts (right ventricular outflow tract [RVOT]) has the potential to vastly expand the population of patients eligible to benefit from nonsurgical restoration of RVOT function. However, knowledge on the performance of the Melody TPV in this setting is limited. Methods and Results—This is a multicenter, retrospective review of the Melody TPV when placed in nonconduit RVOTs, in which at least a portion of the circumference was composed of native tissue. Five centers contributed data on 31 patients. The median age at implantation was 24 years (range, 7–66). At a median follow-up of 15 months, all patients were alive. No patient had greater than mild TPV insufficiency, and the median maximum instantaneous gradients across the RVOT was 23 mm Hg. Stent fracture occurred in 32%. Eight patients developed more than mild TPV obstruction, of whom 6 were associated with identified stent fracture. Three patients developed blood stream infections. There were 5 reinterventions in 3 patients, including 3 repeat TPV implantations and 2 TPV explantations. Conclusions—Melody TPV implantation is feasible in selected patients with RVOTs comprised solely or predominantly native tissue and has the potential to expand the population of patients eligible to benefit from nonsurgical restoration of RVOT function. In early follow-up, valve competency seems preserved. The dominant mechanism of valve dysfunction seems to be related to stent fracture with recurrent obstruction. Additional data are necessary to better understand how to safely expand TPV therapy to this population.

Fontan fenestration closure has no acute effect on exercise capacity but improves ventilatory response to exercise.

OBJECTIVES The aim of this study was to prospectively examine the effects of elective Fontan fenestration closure upon exercise capacity and ventilatory abnormalities. BACKGROUND For patients undergoing Fontan procedures as palliation of single ventricle physiology, the addition of a fenestration to the procedure mitigates perioperative morbidity. Although some fenestrations may close spontaneously, many remain patent and subject patients to arterial hypoxemia and risk for paradoxical emboli. For these reasons fenestration closure is routinely performed post-operatively in the cardiac catheterization laboratory. Although closure of Fontan fenestrations typically results in an immediate improvement in systemic arterial oxygen saturation, it is also associated with an acute decrease in cardiac index and systemic O(2) delivery. The sum result of these physiologic changes upon exercise capacity has not been examined. METHODS Twenty consecutive patients, age 5 to 46 (median 10) years, underwent pre- and post-fenestration closure exercise testing with expiratory gas analysis. RESULTS Before fenestration closure, peak oxygen consumption (VO(2)) was depressed and there was systemic desaturation at rest that worsened with exercise. The ventilatory response to exercise was also abnormal, characterized by elevation of the minute ventilation (VE)/CO(2) elimination slope (VE/VCO(2)), a low end-tidal CO(2), and high end-tidal O(2) at the ventilatory anaerobic threshold. Although arterial saturation improved significantly after fenestration closure, there was no change in peak VO(2) (70.9 +/- 18.6% to 74.0 +/- 18.6%, p = NS), heart rate, or O(2) pulse at peak exercise. In contrast, ventilatory abnormalities (VE/VCO(2)) improved considerably (44.4 +/- 10.9 to 33.3 +/- 5.5, p <or= 0.001). CONCLUSIONS Fontan fenestration closure does not significantly improve peak VO(2). However, ventilatory abnormalities improve considerably.

Transcatheter Tricuspid Valve-in-Valve Implantation for the Treatment of Dysfunctional Surgical Bioprosthetic Valves: An International, Multicenter Registry Study.

Background— Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. Methods and Results— An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II (P<0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. Conclusions— TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.

Intermediate Outcomes in the Prospective, Multicenter Coarctation of the Aorta Stent Trial (COAST)

Background— The Coarctation of the Aorta Stent Trial (COAST) was designed to assess the safety and efficacy of the Cheatham Platinum stent when used in children and adults with native or recurrent coarctation. Acute outcomes have been reported. We report here follow-up to 2 years. Methods and Results— A total of 105 patients underwent attempted implantation, with 104 successes. There were no procedural deaths, serious adverse events, or surgical intervention. All patients experienced immediate reduction in upper- to lower-extremity blood pressure difference with sustained improvement to 2 years. Rates of hypertension and medication use decreased from baseline to 12 months and remained largely unchanged at 2 years. Six aortic aneurysms have been identified: 5 were successfully treated with covered stent placement, and 1 resolved without intervention. Stent fractures were noted in 2 patients at 1 year and 11 patients at 2 years, with evidence of fracture progression. To date, only larger stent diameter was associated with stent fracture. Twelve additional fractures have occurred after 2 years. No fracture has resulted in loss of stent integrity, stent embolization, aortic wall injury, or reobstruction. Nine reinterventions occurred in the first 2 years for stent redilation and address of aneurysms, and 10 additional reinterventions occurred after 2 years. Conclusions— The Cheatham Platinum stent is safe and associated with persistent relief of aortic obstruction. Stent fracture and progression of fracture occur but have not resulted in clinically important sequelae. Reintervention is common and related to early and late aortic wall injury and need for re-expansion of small-diameter stents. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00552812.

Protein-losing enteropathy: integrating a new disease paradigm into recommendations for prevention and treatment

Protein-losing enteropathy is a relatively uncommon complication of Fontan procedures for palliation of complex congenital cardiac disease. However, the relative infrequency of protein-losing enteropathy belies the tremendous medical, psychosocial and financial burdens it places upon afflicted patients, their families and the healthcare system that supports them. Unfortunately, because of the complexity and rarity of this disease process, the pathogenesis and pathophysiology of protein-losing enteropathy remain poorly understood, and attempts at treatment seldom yield long-term success. The most comprehensive analyses of protein-losing enteropathy in this patient population are now over a decade old, and re-evaluation of the prevalence and progress in treatment of this disease is needed. This report describes a single institution experience with the evaluation, management, and treatment of protein-losing enteropathy in patients with congenital cardiac disease in the current era, follows with a comprehensive review of protein-losing enteropathy, focused upon what is known and not known about the pathophysiology of protein-losing enteropathy in this patient population, and concludes with suggestions for prevention and treatment.

Lymphatic Obstruction and Protein-losing Enteropathy in Patients with Congenital Heart Disease

OBJECTIVE Protein-losing enteropathy (PLE) is a known complication of surgical procedures for congenital heart disease. The pathogenesis and pathophysiology of PLE remain poorly understood. However, lymphatic insufficiency appears central to the disease process. We sought to investigate the role of lymphatic obstruction and central venous catheter-related central venous thrombosis in patients with congenital heart disease and PLE. DESIGN A case-control study design was constructed consisting of patients with congenital heart disease and PLE and 2:1 matched controls having undergone the same definitive surgical procedure. Obstruction to lymphatic return was considered present if the thoracic duct was ligated, or if there was complete central venous obstruction at the usual site of thoracic duct drainage. RESULTS Obstruction to lymphatic return was identified in 4 of 16 cases (25%) and 1 of 32 controls (4%), P = .06. There was no association between PLE and central venous catheter use or duration, and no discriminating characteristics between cases and controls with respect to anatomy, pre-Fontan hemodynamic variables, operative or perioperative factors, or hemodynamic variables at the time of PLE diagnosis. Mortality for patients with PLE was 25% compared with 9% in controls (P = not significant). Long-term resolution of PLE was obtained in six patients (38%). CONCLUSION There is a high prevalence of apparent lymphatic obstruction in patients with congenital heart disease and PLE, suggesting that physical lymphatic obstruction may play an important, and previously unrecognized role in the development of PLE in patients with complex congenital heart disease.

Prenatal diagnosis of atrial restriction in hypoplastic left heart syndrome is associated with decreased 2‐year survival

To compare the course of hypoplastic left heart syndrome (HLHS) patients diagnosed prenatally with any degree of atrial restriction with those without evidence of atrial restriction.

Advances in transcatheter interventions in adults with congenital heart disease.

Cardiac catheterization in the adult patient with congenital heart disease clearly is now its own field. The history of the field is closely tied to pediatric cardiac catheterization, in large part because of the individual histories of its patients, and as such, at least for the foreseeable future, these two fields appear inexorably linked. For both, the pace of progress has been swift. This chapter provides a broad review of the important advances in cardiac catheterization that have occurred over the past decade as they pertain to the adult with congenital heart disease, with an emphasis on recent interventional tools and techniques that have revolutionized this exciting field.

Standardizing radiation dose reporting in the pediatric cardiac catheterization laboratory-a multicenter study by the CCISC (Congenital Cardiovascular Interventional Study Consortium).

We examine normalized air Kerma area product (PKA) by body weight (PKA/BW) as a reference value of radiation dose and benchmark PKA/BW in pediatric laboratories using a multicenter registry database.

In the Lab

In contrast to cardiac catheterization in adults, cases in patients with structural heart disease are seldom predictable. Even the most routine catheterization in a patient with congenital heart disease can reveal unexpected findings that completely change the expected course of the procedure. With that said, most cases start and proceed in logical sequence. All cases begin with setting up the table and getting access. Hemodynamic assessment is next, usually followed by angiography and, finally, intervention, if warranted. This is the usual sequence, although exceptions do exist.