Congenital Cardiac Anesthesia Society
A Section of the the Society for Pediatric Anesthesia

{“questions”:{“n9dwa”:{“id”:”n9dwa”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: M. Barbic, MD AND M. Gangadharan, MD, FAAP, FASA – Children\u2019s Memorial Hermann Hospital, University of Texas Health Science Center, Houston, TX \r\n\r\nAn echocardiogram obtained on a 26-hour-old, full-term girl due to differential cyanosis and suspected congenital heart disease demonstrates an interrupted aortic arch. Which of the following subtypes of interrupted aortic arch is MOST likely in this patient? \r\n\r\n\r\n”,”desc”:”EXPLANATION \r\nInterrupted aortic arch (IAA) is a rare, ductal-dependent, congenital cardiac anomaly with an incidence of about 0.03 to 0.19 per 10,000 live births and constitutes 1-5% of congenital heart diseases. It is characterized by a disruption in the lumen of the aortic arch at various sites between the ascending and descending aorta. \r\n \r\nClassification of IAA is based on the site of the interruption. Type A interruption occurs distal to the left subclavian artery and is the second most common type, representing 10-20 % of cases. Type B interruption occurs between the left carotid and left subclavian artery. It is the most common type of IAA, representing 70-80% of cases (Figure 1). Type C is the least common type, representing less than 5% of cases, and occurs between the innominate and left carotid artery. Over 70% of Type B interruptions are associated with deletion of chromosome 22q11. The most commonly associated cardiac abnormalities are a ventricular septal defect (VSD), a bicuspid aortic valve, and an aberrant right subclavian artery arising from the descending aorta. The VSD is typically posteriorly malaligned and can result in left ventricular outflow tract obstruction. Perfusion distal to the interruption is critically dependent on a patent ductus arteriosus (PDA). Ductal closure will lead to lower body hypoperfusion, severe metabolic acidosis, and multiorgan failure. Differential cyanosis, with lower pedal oxygen saturation, may or may not be present depending on the degree of mixing at the level of the VSD. The ratio of pulmonary vascular resistance to systemic vascular resistance will determine the direction of flow across the PDA. \r\n\r\n\r\n\r\n \r\n \r\n \r\n\r\n\r\n \r\n\r\n\r\n\r\n\r\n\r\n\r\n \r\n \r\n\r\n\r\n\r\n\r\nPrenatal diagnosis of IAA by ultrasound is possible in more than 50% of patients. The advantage of prenatal diagnosis is that treatment with prostaglandin E1 (PGE1) will begin immediately after birth. When the diagnosis is not made before birth, most patients will present with signs of cardiogenic shock after spontaneous closure of the PDA. Patients often present with end-organ dysfunction, such as necrotizing enterocolitis, liver and kidney dysfunction, and coagulopathy. Physical exam findings include lethargy, delayed capillary refill, cool skin, decreased peripheral pulses, and hypotension. Transthoracic echocardiography is usually adequate to delineate the anatomy of the aortic interruption, the patency of the PDA, the location of arch vessels, characteristics of the VSD, LV size and function, LVOT morphology, and size of aortic valve. A three-dimensional volume-rendered computed tomography angiogram may be obtained if further anatomic clarification is required. In extremely rare instances, in which the ductus arteriosus remains patent and collateral arterial vessels develop, patients may survive to adulthood before diagnosis.\r\n\r\nPrimary single-stage surgical repair is usually performed in the neonatal period after medical stabilization in the intensive care unit. The goals of medical management are maintenance of ductal patency with intravenous PGE1, avoiding decreases in pulmonary vascular resistance by minimizing fractional inspired oxygen concentration (FiO2), and maintaining cardiac output with inotropic agents, if needed, and balancing the ratio of pulmonary and systemic blood flow. The surgical repair consists of augmentation of the arch with graft material, if necessary, and anastomosis of the ascending and descending aorta to re-establish luminal continuity. Cardiopulmonary bypass may involve arterial cannulation through the ascending aorta or innominate artery for cerebral perfusion and the PDA for distal perfusion of the lower body. Selective cerebral perfusion or deep hypothermic circulatory arrest may be employed during arch repair. Early postoperative complications include bleeding, recurrent laryngeal nerve and phrenic nerve injury, and acute kidney injury. Late postoperative complications include aortic arch obstruction, LVOTO, and obstruction of the left main bronchus. Hybrid palliation with bilateral pulmonary artery bands and ductal stenting is an option when complete primary correction is not possible, such as prematurity or contraindications to cardiopulmonary bypass. Patients with IAA need lifelong follow-up by a cardiologist and for associated comorbidities. About 20-30% of patients will need repeat interventions in the cardiac catheterization suite or the cardiac operating room. \r\n\r\nThe correct answer is Type B, which is the most common type of IAA, representing 70 to 80% of cases of IAA. Type A is the second most common (10-20%), and Type C is the least common (<5%). \r\n\r\n\r\n \r\nREFERENCES \r\nBurbano-Vera N, Zaleski KL, Latham GJ, Nasr VG. Perioperative and Anesthetic Considerations in Interrupted Aortic Arch. Semin Cardiothorac Vasc Anesthesia<\/em>. 2018;22(3):270-277. doi:10.1177\/1089253218775954\r\n\r\nLaPar DJ, Baird CW. Surgical Considerations in Interrupted Aortic Arch. Semin Cardiothorac Vasc Anesth<\/em>. 2018;22(3):278-284. doi: 10.1177\/1089253218776664. \r\n\r\nBoutaleb AM, Tabat M, Mekouar Y, Bennani G, Drighil A, Habbal R. Rare case series of adult interrupted aortic arch. J Cardiol Cases<\/em>. 2023;28(5):206-209. doi:10.1016\/j.jccase.2023.07.004″,”hint”:””,”answers”:{“f5vfd”:{“id”:”f5vfd”,”image”:””,”imageId”:””,”title”:”A.\tType A”},”ojz7q”:{“id”:”ojz7q”,”image”:””,”imageId”:””,”title”:”B.\tType B”,”isCorrect”:”1″},”6jy62″:{“id”:”6jy62″,”image”:””,”imageId”:””,”title”:”C.\tType C”}}}}}

{“questions”:{“wxgng”:{“id”:”wxgng”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Katarzyna Dlugosz Sledz, MD and M. Gangadharan, MD, FAAP, FASA – Children\u2019s Memorial Hermann Hospital, University of Texas Health Science Center, Houston, TX AND Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 20-year-old woman with a history of pulmonary hypertension treated with riociguat presents for a pulmonary hypertension study. Which of the following mechanisms BEST describes the pharmacologic action of riociguat? “,”desc”:”EXPLANATION \r\nPulmonary hypertension is defined by mean pulmonary artery pressure (PAP) greater than 20 mmHg at rest in a biventricular heart and the transpulmonary gradient is > 6mmHg in a univentricular heart in pediatric patients greater than three months of age. Pulmonary arterial hypertension, also termed precapillary pulmonary hypertension, is additionally characterized by a pulmonary vascular resistance index (PVRI) greater than three wood units per m^{2<\/sup>. Referral to a pediatric pulmonary hypertension specialist is a necessity for the diagnosis and management of pediatric patients with pulmonary hypertension. Formal diagnosis is made by cardiac catheterization and acute vasoreactivity testing. Treatment consists of diuretics, anticoagulants, digoxin, supplemental oxygen, and calcium channel blockers in patients with positive acute pulmonary vasoreactivity. Patients with negative vasoreactivity testing are typically treated with the addition of one or more pulmonary vasodilators.\r\n \r\n\r\nThree mediators, endothelin, nitric oxide, and prostacyclin, regulate pulmonary arterial vascular tone. The molecular pathways for these mediators are illustrated in the figure 1 below, along with the therapeutic targets for each. The endothelin pathway mediates vasoconstriction, whereas the prostacyclin and nitric oxide pathways mediate vasodilatation. Targeted therapies are aimed at improving the balance between vasoconstriction and vasodilation which is abnormal in pulmonary hypertension.\r\n \r\n\r\n \r\n\r\nFigure 1. Molecular targets for pulmonary hypertension drug therapies. Newly approved therapies are listed in blue. cAMP, cyclic adenosine monophosphate; cGMP, cyclic guanylate monophosphate; ERA, endothelin receptor antagonist; FDA, US Food and Drug Administration; INH, inhaled; IP2, prostacyclin receptor 2; IV, intravenous; NO, nitric oxide; PAH, pulmonary arterial hypertension; PDE-5, phosphodiesterase-5; PDE-5i, phosphodiesterase-5 inhibitor; PGI2, prostaglandin I2; sGC, soluble guanylate cyclase; SQ, subcutaneous. (Tsai H, Sung YK, and de Jesus Perez V. Recent advances in the management of pulmonary arterial hypertension. F1000Research<\/em>. 2016;5:2755. Creative Commons License)\r\n\r\n\r\nProstacyclin analogs, such as iloprost, epoprostenol, and treprostinil, increase cyclic adenosine monophosphate (cAMP) levels in pulmonary vascular smooth muscle cells resulting in vasodilation. Endothelin receptor blockers, such as bosentan, ambrisentan, and macitentan prevent vasoconstriction and smooth muscle proliferation via endothelin A and B receptor blockade. The nitric oxide pathway results in increased levels of cyclic guanylate monophosphate (cGMP), which mediates pulmonary vasodilation. Exogenous administration of nitric oxide increases the production of cGMP, while phosphodiesterase inhibitors, such as sildenafil and tadalafil, reduce the breakdown of cGMP.\r\n\r\n\r\nRiociguat is a direct soluble guanylate cyclase (sGC) stimulator that increases the sensitivity of guanylate cyclase to nitric oxide, resulting in increased intracellular cGMP levels, which in turn leads to a vasodilatory and antiproliferative effect on vascular smooth muscle. Riociguat (trade name Adempas\u00ae) has been approved by the European Medicines Agency to treat pulmonary hypertension in children older than six 6 years with systolic blood pressure greater than 90 mmHg and children older than 12 years with systolic blood pressure greater than 95mmHg. Riociguat has not received FDA approval for pediatric use in the United States. The side effects of riociguat include systemic hypotension, hemoptysis, pulmonary hemorrhage, headache, and nausea. Concomitant use of riociguat with a phosphodiesterase-5 inhibitor is contraindicated due to an exaggerated effect on blood pressure. There are case reports of the successful use of riociguat in children. Domingo and colleagues reported two cases of infants with refractory supra-systemic pulmonary hypertension who were weaned off nitric oxide after the administration of riociguat.\r\n\r\n\r\nThe correct answer is B. Riociguat is a direct soluble guanylate cyclase (sGC) stimulator that increases the sensitivity of guanylate cyclase to nitric oxide, resulting in increased levels of intracellular cGMP. Although sildenafil and tadalafil also act via the nitric oxide pathway, they produce their therapeutic effect via phosphodiesterase-5 inhibition. Bosentan and ambrisentan are endothelin receptor antagonists. \r\n\r\n\r\n \r\nREFERENCES \r\n\r\nBeghetti M, Gorenflo M, Ivy DD, Moledina S, Bonnet D. Treatment of pediatric pulmonary arterial hypertension: A focus on the NO-sGC-cGMP pathway. Pediatr Pulmonol<\/em>. 2019;54(10):1516-1526. doi:10.1002\/ppul.24442\r\n\r\n\r\nhttps:\/\/www.ema.europa.eu\/en\/documents\/product-information\/adempas-epar-product-information_en.pdf Accessed on 9.7.2024\r\n\r\n\r\nDomingo LT, Ivy DD, Abman SH, et al. Novel use of riociguat in infants with severe pulmonary arterial hypertension unable to wean from inhaled nitric oxide. Front Pediatr<\/em>. 2022; 10:1014922. doi:10.3389\/fped.2022.1014922\r\n\r\n\r\nHansmann G, Koestenberger M, Alastalo TP, et al. 2019 updated consensus statement on the diagnosis and treatment of pediatric pulmonary hypertension: The European Pediatric Pulmonary Vascular Disease Network (EPPVDN), endorsed by AEPC, ESPR, and ISHLT. J Heart Lung Transplant<\/em>. 2019;38(9):879-901. doi:10.1016\/j.healun.2019.06.022\r\n\r\n\r\nJone PN, Ivy DD, Hauck A, et al. Pulmonary Hypertension in Congenital Heart Disease: A Scientific Statement From the American Heart Association. Circ Heart Fail<\/em>. 2023;16(7):e00080. doi:10.1161\/HHF.0000000000000080\r\n\r\n”,”hint”:””,”answers”:{“eig31”:{“id”:”eig31″,”image”:””,”imageId”:””,”title”:”A)\tEndothelin receptor blockade”},”0h8g8″:{“id”:”0h8g8″,”image”:””,”imageId”:””,”title”:”B)\tDirect stimulation of soluble guanylate cyclase”,”isCorrect”:”1″},”cxut0″:{“id”:”cxut0″,”image”:””,”imageId”:””,”title”:”C)\tInhibition of phosphodiesterase-5 \r\n\r\n”}}}}}}

{“questions”:{“dmrgw”:{“id”:”dmrgw”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: M.Gangadharan, MD, FAAP, FASA Children\u2019s Memorial Hermann Hospital, University of Texas Health Science Center, Houston, TX AND K.L. Richards, MD, Children\u2019s Hospital of Los Angeles, Univ. of Southern California, Keck School of Medicine, Los Angeles, CA \r\n\r\nThe echocardiogram of a newborn boy with clinical features of Trisomy 21 reveals a complete atrioventricular septal defect. The superior bridging leaflet of the atrioventricular valve has no chordal attachments to either ventricle. According to the Rastelli classification, what type of morphology BEST describes this atrioventricular valve?\r\n”,”desc”:”EXPLANATION \r\n Atrioventricular septal defects (AVSD) occur at a frequency of 2 per 10,000 live births and constitute about 3% of cardiac malformations. The defect is characterized by the combination of an ostium primum atrial septal defect (ASD), an inlet ventricular septal defect (VSD), and an abnormal atrioventricular valve (AVV) straddling the left and right chambers of the heart. It results from the failure of endocardial cushions to fuse in the fifth week of intrauterine development. The abnormal atrioventricular valve usually has five leaflets: the superior bridging leaflet (SBL), the inferior bridging leaflet (IBL), the right mural leaflet, the right antero-superior leaflet, and the left mural leaflet. The valve may have a single orifice, or two orifices as shown in Figure 1 below.\r\n\r\n The pattern of the chordal septal attachments of the superior bridging leaflet (SBL) described by Rastelli is used to classify the morphology of the common atrioventricular valve into three subtypes. Rastelli type A, the most common subtype occurring in 75% of cases, consists of a superior bridging leaflet which is attached to the left ventricular septum through multiple chordal attachments. The AVV in type A is divided at the septum into left and right components. Rastelli type B, the rarest subtype, is characterized by a large SBL that extends across the interventricular septum and is attached to the right ventricle through an anomalous papillary muscle. The Rastelli type C atrioventricular valve consists of a very large SBL which is \u201cfree-floating\u201d and unattached. The Rastelli classification may be used to determine the type of approach through either a one-patch or a two-patch technique.\r\n\r\n\r\n \r\nFigure 1. AVSD. (Rigby M. Atrioventricular Septal Defect: What Is in a Name?. J Cardiovasc Dev Dis<\/em>. 2021;8(2):19. Distributed under Creative Commons Attribution License ) \r\n\r\nIn addition to complete atrioventricular septal defect, there are also partial and transitional atrioventricular septal defects. Partial AVSDs consist of an ostium primum ASD and a gap at the zone of apposition between the left side of the SBL and IBL, which is often called a cleft. Transitional AVSDs consist of an ostium primum ASD, a restrictive VSD below the common atrioventricular valve, and a cleft. \r\n\r\n Several cardiac malformations may occur with AVSD such as left ventricular inflow tract and outflow tract obstruction, tetralogy of Fallot, persistent left superior vena cava, coarctation of aorta, and heterotaxy. The common atrioventricular valve may open predominantly into the left or right ventricle resulting in an unbalanced AVSD and single ventricle physiology. Rastelli type A is associated with a narrow left ventricular outflow tract, often described as a \u201cgooseneck deformity.\u201d Rastelli type C is associated with tetralogy of Fallot. Complete diagnosis in the newborn period is usually possible with transthoracic echocardiography. \r\n\r\n Multiple chromosomal anomalies have been associated with complete atrioventricular septal defects. It occurs in approximately 20% of infants and children with Trisomy 21 and is also commonly associated with tetralogy of Fallot. Complete AVSD occurs in almost all patients with asplenia and 25% of patients with polysplenia. In addition, 8p deletion syndrome, Trisomy 9, and Trisomy 18 are also associated with CAVSD.\r\n\r\nThe superior bridging leaflet of the atrioventricular valve described in the stem has no attachments, which describes the Rastelli type C morphology, unlike Rastelli type A and B. \r\n\r\n \r\nREFERENCES \r\nWalker SG. Anesthesia for Left-to-Right Shunt Lesions. In: Andropoulos DB, Mossad EB, Gottlieb EA. Anesthesia for Congenital Heart Disease<\/em>. 4th Edition. Hoboken, NJ: John Wiley & Sons Ltd, Blackwell Publishing; 2023:636-637.\r\n\r\nRigby M. Atrioventricular Septal Defect: What Is in a Name? J Cardiovasc Dev Dis<\/em>. 2021;8(2):19. doi:10.3390\/jcdd8020019 \r\n\r\nCalabr\u00f2 R, Limongelli G. Complete atrioventricular canal. Orphanet J Rare Dis<\/em>. 2006;1:8. doi:10.1186\/1750-1172-1-8 \r\n\r\nMarino B, Vairo U, Corno A, et al. Atrioventricular canal in Down syndrome. Prevalence of associated cardiac malformations compared with patients without Down syndrome. Am J Dis Child<\/em>. 1990;144(10):1120-1122. doi:10.1001\/archpedi.1990.02150340066025\r\n\r\n”,”hint”:””,”answers”:{“fi84k”:{“id”:”fi84k”,”image”:””,”imageId”:””,”title”:”A)\tRastelli type A”},”9hm3l”:{“id”:”9hm3l”,”image”:””,”imageId”:””,”title”:”B)\tRastelli type B”},”fyu21″:{“id”:”fyu21″,”image”:””,”imageId”:””,”title”:”C)\tRastelli type C\r\n\r\n”,”isCorrect”:”1″}}}}}

{“questions”:{“zyhh8”:{“id”:”zyhh8″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Meera Gangadharan MBBS, FAAP, FASA, University of Texas Health Science Center at Houston\/Children\u2019s Memorial Hermann Hospital AND Destiny F. Chau MD, University of Arkansas for Medical Sciences\/Arkansas Children\u2019s Hospital, Little Rock, AR \r\n\r\nWhich of the following coronary artery arrangements is MOST commonly associated with D-transposition of the great arteries?\r\n\r\n\r\n\r\n\r\nCreative Commons Licensing from Gittenberger-de Groot et al. J Thorac Cardiovasc Surg<\/em>. 2018;156(6):2260-2269″,”desc”:”EXPLANATION \r\nDextro transposition of the great arteries (D-TGA) is characterized by ventriculoarterial discordance and atrioventricular concordance. D-TGA comprises approximately 5% of all congenital heart lesions and is one of the most common cyanotic congenital heart diseases to present in the newborn period with an incidence of roughly 3 per 10,000 live births. The aorta arises from the morphologic right ventricle and the pulmonary artery from the morphologic left ventricle. Patients usually have levocardia, situs solitus, and D-looped ventricles. The relative position of the aortic valve to the pulmonary valve may vary. Still, the most common arrangement is the aortic valve orifice to the right and anterior to the pulmonary valve orifice. The ventricular septum may be intact or there may be a ventricular septal defect. Left ventricular outflow tract obstruction may also be present. \r\n\r\n\r\nCoronary artery anomalies are another hallmark of transposition of the great arteries and efforts have been made to describe the coronary artery configurations in a standardized manner. Due to variations in the relative positions of the aortic and pulmonary valves to each other, the aortic valve orifice may be side-by-side, right and anterior to, or directly anterior to the pulmonary valve. The origin and subsequent course of the coronary arteries result in several different patterns. The two most common systems for describing the coronary artery configuration in D-TGA are the Yacoub classification described in 1978 and the more common Leiden Convention. The Leiden Convention was originally published in the early 1980s and was modified in 2018. It places the observer in the non-coronary cusp facing the pulmonary artery, with the right hand labeled \u201csinus 1\u201d and the left hand labeled \u201csinus 2\u201d. The classification then describes from which sinus each of the three major coronary arteries arise (Fig.1). \r\n\r\n\r\n \r\n \r\nFigure 1: Illustration of Leiden nomenclature determination. [Creative Commons Licensing from Gittenberger-de Groot et al. J Thorac Cardiovasc Surg<\/em>. 2018;156(6):2260-2269.] \r\n\r\n\r\nThe most common surgery performed for D-TGA in the current era is the Jatene arterial switch operation (ASO). This involves transecting the pulmonary artery and aorta, a few millimeters distal to their valves and anastomosing the pulmonary artery segment to the aortic root and the aorta to the pulmonary root. The operation also requires that the coronaries be translocated to the neo-aortic (pulmonary) root. From a surgical perspective, coronary artery patterns can be grouped into three main categories: (1) the \u201cusual\u201d coronary pattern (70% of cases), as depicted in answer option (A), where the left and right coronaries originate from separate sinuses with the left coronary dividing into left anterior descending and circumflex branches. Coronary transfer is usually straightforward and associated with excellent outcomes; (2) coronary arteries with an anterior or posterior loop (25% of cases), in which the coronary transfer may be difficult; and (3) coronary artery pattern with a single origin or where the coronaries course between the major arterial trunks, which may be associated with an intramural segment. Coronary transfer is usually difficult and represents a high risk for morbidity and mortality. Hence a detailed description of coronary artery anatomy before surgery is critical to avoid kinking, stretching, or placing tension on the coronary arteries when they are translocated. \r\n\r\n\r\nThe most common (\u201cusual\u201d) coronary artery pattern present in approximately 70% of cases of D-TGA is shown in answer option A. The other two patterns are much less commonly associated with D-TGA. \r\n\r\n\r\n\r\n \r\nREFERENCES \r\n\r\nGittenberger-de Groot AC, Koenraadt WMC, Bartelings MM, et al. Coding of coronary arterial origin and branching in congenital heart disease: The modified Leiden Convention. J Thorac Cardiovasc Surg<\/em>. 2018;156(6):2260-2269. doi:10.1016\/j.jtcvs.2018.08.009\r\n\r\n\r\nYacoub MH, Radley-Smith R. Anatomy of the coronary arteries in transposition of the great arteries and methods for their transfer in anatomical correction. Thorax<\/em>. 1978;33(4):418-424. doi:10.1136\/thx.33.4.418\r\n\r\n\r\nQureshi AM, Justino H, Heinle JS. Transposition of the Great Arteries. In: Shaddy R, Penny D, Feltes T, Cetta F, Mital S. Moss & Adams heart disease in infants, children, and adolescents: Including the fetus and young adult<\/em>. 10th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2022: 1122-1142. \r\n\r\n\r\nAhlstr\u00f6m L, Odermarsky M, Malm T, Johansson Ramgren J, Liuba P. Preoperative coronary anatomy assessment with echocardiography and morbidity after arterial switch operation of transposition of the great arteries. Pediatr Cardiol<\/em>. 2018;39(8):1620-1626. doi:10.1007\/s00246-018-1939-z\r\n\r\n”,”hint”:””,”answers”:{“m0krq”:{“id”:”m0krq”,”image”:””,”imageId”:””,”title”:”A. Image A Above “,”isCorrect”:”1″},”kptwb”:{“id”:”kptwb”,”image”:””,”imageId”:””,”title”:”B. Image B Above”},”zhdhm”:{“id”:”zhdhm”,”image”:””,”imageId”:””,”title”:”C. Image C Above “}}}}}

{“questions”:{“6kwwk”:{“id”:”6kwwk”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Cori Banerdt, MD – Vanderbilt Children\u2019s Hospital\/Vanderbilt University Medical Center, Nashville, TN AND\r\nDestiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 17-year-old patient with dilated cardiomyopathy is Status 1A on the heart transplantation list. The isohemagglutinin titer, drawn two days prior, is 1:32. According to the Organ Procurement and Transplantation Network (OPTN) policy changes in 2023, which of the following listing criteria MOST likely disqualifies this patient for ABO-incompatible heart transplantation?\r\n”,”desc”:”EXPLANATION \r\nPediatric patients with refractory heart failure placed on the cardiac transplantation waiting list have significant mortality due to long wait times related to the scarcity of donor organs. Furthermore, a proportion of patients with certain ABO blood types have even longer waitlist times. Specifically, recipients with type O blood have the longest waitlist time and can only receive O-type donor organs because of the presence of both anti-A and anti-B antibodies (isohemagglutinins). The immaturity of the immune system in infants prompted the first incompatible blood type (ABOi) heart transplantations in the 1990s. \r\n\r\nCurrently, ABOi heart transplants in young children are routinely performed. Reports in the literature indicate that the long-term outcomes of both compatibility groups are similar. In July 2016, the Organ Procurement and Transplantation Network (OPTN) expanded the candidacy for ABOi heart transplantation from patients younger than one year of age to include patients one to two years of age, as well as increasing the isohemagglutinin titers from 1:4 to 1:16 in this age group. After this policy change, a study using the Scientific Registry of Transplant Recipients database demonstrated that the percentage of ABOi transplantations increased by 2.7-fold, and the waiting times decreased by 68% for children listed for ABOi transplants compared to those listed for ABO compatible (ABOc) transplants. The survival rates were similar in children who received an ABOi versus ABOc heart transplant.\r\n\r\nIn March 2023, the OPTN Executive Committee approved further policy changes, which allowed transplant programs to indicate they were willing to accept an ABOi donor heart and\/or donor heart-lung for status 1A and 1B candidates placed on the waiting list before their 18th birthday. Transplant programs must report isohemagglutinin titers equal to or less than 1:16 to the OPTN every 30 days on behalf of such candidates. Previously, candidates had to be registered before their 2nd birthday. \r\n \r\nPediatric status assignments include status 1A, 1B, 2, and inactive. To be listed status 1A, a pediatric candidate must be less than 18 years of age at the time of registration and require therapy with one or more of the following: 1) continuous mechanical ventilation; 2) an intra-aortic balloon pump; 3) a stent or prostaglandin infusion to maintain ductal-dependent circulation; 4) multiple inotropic infusions or a single inotrope at high dose to treat hemodynamically unstable heart failure; or 5) a mechanical circulatory support device. Pediatric status 1A must be recertified every 14 days. \r\n\r\nThe correct answer is B. The patient described in the stem is 17 years old, status 1A, and has a recent isohemagglutinin titer of 1:32. Although the other criteria set by the most current OPTN policy are met, the isohemagglutinin titer is greater than 1:16. Therefore, this patient is a candidate for an ABOc, but not ABOi heart transplantation. \r\n\r\n \r\nREFERENCES \r\nBansal N, West LJ, Simmonds J, Urschel S. ABO-incompatible heart transplantation-evolution of a revolution. J Heart Lung Transplant<\/em>. 2024. 43(9):1514-1520. \r\n\r\nMilligan C, Daly KP. ABO-Incompatible heart transplantation: where science, society, and policy collide. J Card Fail<\/em>. 2024;30(3):486-487. \r\n\r\nAmdani S, Deshpande SR, Liu W, Urschel S. Impact of the pediatric ABO policy change on listings, transplants, and outcomes for children younger than 2 years listed for heart transplantation in the United States. J Card Fail<\/em>. 2024;30(3):476-485. \r\n\r\nOrgan Procurement and Transplantation Network. Notice of OPTN Policy Changes. Modify heart policy for intended incompatible blood type (ABOi) offers to pediatric candidates. Updated June 26, 2023. Accessed July 27 2024.\r\nhttps:\/\/optn.transplant.hrsa.gov\/media\/05vnqa0k\/optn_heart_aboi-offers_pn_june-2023.pdf\r\n\r\nOrgan Procurement and Transplantation Network Policies. Updated July 25, 2024. Accessed July 30, 2024. https:\/\/optn.transplant.hrsa.gov\/media\/eavh5bf3\/optn_policies.pdf\r\n\r\n”,”hint”:””,”answers”:{“wceai”:{“id”:”wceai”,”image”:””,”imageId”:””,”title”:”A.\tAge”},”zz0ks”:{“id”:”zz0ks”,”image”:””,”imageId”:””,”title”:”B.\tIsohemagglutinin titer “,”isCorrect”:”1″},”iiq2x”:{“id”:”iiq2x”,”image”:””,”imageId”:””,”title”:”C.\tListing status”}}}}}