Audrey C. Marshall

Percutaneous left atrial decompression in patients supported with extracorporeal membrane oxygenation for cardiac disease.

Objectives: Left atrial decompression using cardiac catheterization techniques has been described at centers with extracorporeal membrane oxygenation programs. Left atrial decompression can decrease cardiogenic edema, minimize ventricular distension, and allow myocardial recovery. We describe Boston Children’s Hospital’s experience with percutaneous left atrial decompression techniques, acute outcomes, and clinical impact of left atrial decompression in extracorporeal membrane oxygenation patients. Subjects: Patients supported with extracorporeal membrane oxygenation undergoing percutaneous left atrial decompression were identified and assigned to two groups 1) myocarditis/suspected myocarditis or 2) nonmyocarditis cardiac disease. Interventions: Three techniques including vent placement, static balloon dilation, and stent implantation were used. Measurements and Main Results: Change in left atrial pressure and severity of pulmonary edema on chest radiography pre and post procedure, impact of timing and technique of left atrial decompression on resolution of left atrial hypertension, and extracorporeal membrane oxygenation survival were evaluated. Furthermore, we evaluated the presence of residual atrial septal defect during follow-up. Percutaneous left atrial decompression was performed in 44 of 419 extracorporeal membrane oxygenation cases (10.5%) and was frequently used for myocarditis (22 of 44 patients; 50%). Techniques included 25 vents, 17 static balloon dilations, and two stents. All techniques were equally successful and significantly reduced left atrial pressure and pulmonary edema. Survival to hospital discharge was not associated with extracorporeal membrane oxygenation duration prior to left atrial decompression, change in left atrial pressure, or technique used. Persistent atrial septal defect was noted in five surviving patients (excluding transplant recipients and deceased), two required closure. Conclusions: Left atrial decompression can be performed effectively in children on extracorporeal membrane oxygenation using various percutaneous techniques. Reduction in pulmonary venous congestion is usually evident by chest radiography within 48 hours of intervention. Persistent atrial septal defect may require closure at the time of extracorporeal membrane oxygenation decannulation or during long-term follow-up.

Adjunct Targeted Biologic Inhibition Agents to Treat Aggressive Multivessel Intraluminal Pediatric Pulmonary Vein Stenosis

Objective To evaluate the use of imatinib mesylate with or without bevacizumab targeting neoproliferative myofibroblast‐like cells with tyrosine kinase receptor expression, as adjuncts to modern interventional therapies for the treatment of multivessel intraluminal pulmonary vein stenosis (PVS). We describe the 48‐ and 72‐week outcomes among patients receiving imatinib mesylate with or without bevacizumab for multivessel intraluminal PVS. Study design This single‐arm, prospective, open‐label US Food and Drug Administration approved trial enrolled patients with ≥2 affected pulmonary veins after surgical or catheter‐based relief of obstruction between March 2009 and December 2014. Drug therapy was discontinued at 48 weeks, or after 24 weeks of stabilization, whichever occurred later. Results Among 48 enrolled patients, 5 had isolated PVS, 26 congenital heart disease, 5 lung disease, and 12 both. After the 72‐week follow‐up, 16 patients had stabilized, 27 had recurred locally without stabilization, and 5 had progressed. Stabilization was associated with the absence of lung disease (P = .03), a higher percentage of eligible drug doses received (P = .03), and was not associated with age, diagnosis, disease laterality, or number of veins involved. Survival to 72 weeks was 77% (37 of 48). Adverse events were common (n = 1489 total), but only 16 were definitely related to drug treatment, none of which were serious. Conclusion Survival to 72 weeks was 77% in a referral population with multivessel intraluminal PVS undergoing multimodal treatment, including antiproliferative tyrosine kinase blockade. Toxicity specific to tyrosine kinase blockade was minimal.

Transcatheter Intervention of Coronary Obstructions in Infants, Children, and Young Adults

This study assesses the characteristics of coronary obstructions that underwent transcatheter intervention in a pediatric catheterization laboratory, the procedural details, and patient outcomes. Acute cardiac failure due to coronary obstructions in children is rare. The role of catheter based intervention is largely unreported. Single center retrospective review between January 2000 and December 2016. Thirty-three patients (median age 2y/o [0–38], weighing 9.6xa0kg [2.2–91]) underwent 39 transcatheter interventions on 39 lesions, mainly left main coronary (16/39; 39%) and right coronary (9/39; 23%) arteries. Most patients had congenital heart disease (29/33; 88%). Cath indications included ventricular dysfunction (17), cardiac arrest (7), failure to wean from cardiopulmonary bypass (5), and other (4). Almost half (18/39; 46%) were performed on ECMO support. Obstructions were post-surgical (16; 4 with coronary manipulation), thrombotic (13; 5u2009<u200930xa0days from cardiac surgery), and miscellaneous lesions (10). Interventions included 25 bare metal stents implanted in 22 lesions in 17 patients (mainly post-surgical lesions; 3xa0at Damus–Kaye–Stansel anastomosis), nine balloon angioplasty only, four lytic therapyu2009±u2009mechanical disruption of thrombus, and four technical failures. There were no procedure-related deaths. Most patients survived to discharge or transplant (24/33; 73%). Six patients who received stents had follow-up catheterization (median 15.5xa0months [1–106]); all were without restenosis. Most coronary obstructions intervened upon in a pediatric cath lab were on young, critically ill patients with congenital heart disease secondary to surgical manipulation/injury or thrombosis. Transcatheter intervention should be considered a potential treatment strategy in this population.

Targeted Increase in Pulmonary Blood Flow in a Bidirectional Glenn Circulation

In patients with a Glenn shunt and unilateral pulmonary vascular abnormalities, supplemental pulmonary blood flow may improve antegrade flow in the target lung and may permit eventual Fontan completion, while mitigating the risks of uncontrolled additional flow to the contralateral lung. We attempted this by inserting a small aortopulmonary shunt into the affected pulmonary artery and banding the central pulmonary artery. We performed a retrospective review of all patients who underwent this procedure from 2000 to 2015. Comparisons of nonparametric variables were performed with the Wilcoxon signed rank test. Twenty patients were followed for a median of 36 months. Vascular abnormalities included recalcitrant unilateral pulmonary arterial (nu2009=u20098) or venous (nu2009=u20095) obstruction or hypoplasia, combined disease (nu2009=u20094), or abundant aortopulmonary collaterals (nu2009=u20093). Nine had retrograde flow from the affected lung. The most frequent complications were pleural effusions (nu2009=u20094) and shunt thrombosis (nu2009=u20094). Postoperatively, all patients demonstrated antegrade flow to the target lung at the earliest postoperative catheterization. Glenn pathway pressures and saturations were unchanged, whereas the shunted pulmonary arterial oxygen saturation and pressure increased by 4% (Pu2009=u20090.04) and 6xa0mmxa0Hg (Pu2009=u20090.04), respectively. Three patients died; 9 achieved definitive palliation, 4 were deemed to have no improvement, and 4 continue to have a contralaterally shunted Glenn at this time. Targeted additional pulmonary blood flow may be useful for the palliation of single ventricle patients with abnormal pulmonary vasculature. However, morbidity and mortality are common in this high-risk population.

Echocardiographic predictors of neonatal illness severity in fetuses with critical left heart obstruction with intact or restrictive atrial septum

Neonates with critical left heart obstruction and intact atrial septum (IAS) or restrictive atrial septum (RAS) are at risk for hypoxia within hours of birth and remain a group at high risk for mortality.

Clinical and Hemodynamic Results After Conversion from Single to Biventricular Circulation After Fetal Aortic Stenosis Intervention

At our institution a multidisciplinary team has performed fetal aortic valvuloplasty (FAV) for severe aortic stenosis with evolving hypoplastic left heart syndrome with high technical success rates. Measurement of postnatal success has been biventricular circulation (BC). Postnatal survival for patients after FAV who achieved a BC appears encouraging. However, there are limited late clinical and hemodynamic outcomes in this cohort and there is concern for diastolic dysfunction. We reviewed all patients with FAV at our institution who initially underwent single ventricle palliation and subsequently BC, as this is likely the subset at high-risk for poor outcomes. Clinical, imaging, and surgical data were collected. Two of 7 patients (29%) died within 16 months of BC, and 1 patient has been listed for transplant. Diastolic dysfunction was common and progressive with median left ventricular end diastolic pressure of 12xa0mm Hg before BC, and increasing to 22xa0mm Hg for survivors at last follow-up. Left ventricular size was adequate with all patients reaching a left ventricular end diastolic volume (LVEDV) z score in the normal or elevated range. Presence and severity of residual valve lesions decreased over time secondary to a median of 6 interventions (range 3 to 10), either surgical or cath-based, performed for these 7 patients during the study period. In conclusion, clinical outcomes are concerning for this high-risk group. Diastolic dysfunction is persistent and progressive despite anatomic interventions and adequate left ventricular growth. The main contributing factor to poor outcomes may be intrinsic myocardial dysfunction and primordial pathology. Achievement of a BC after FAV may not be an appropriate measure of success.