Andersons pediatric cardiology 1755

Patient Selection Long-term MCS is generally used when patients have failed medical therapy for severe heart failure Heart failure in children is not uncommon, with more than 14,000 hospitalizations annually in the United States, with diverse etiologies including congenital heart disease (CHD), cardiomyopathy, and myocarditis.3 The majority of VADs in children nowadays are used in patients with DCM Although CHD accounts for 60% to 70% of heart failure–related hospitalizations, only 20% of VADs are implanted in children in CHD.3,4 The underlying disease and size of the patient are important considerations for the type of VAD used Disease severity is important for consideration and timing of MCS Many children with less advanced stages of heart failure can be managed on oral therapy as outpatients with few cardiac-related symptoms.5 Indeed, a substantial minority of children with DCM will have improvement and even normalization of their ventricular function over time.6,7 However, heart failure is a severe, progressive disease that carries a high risk of major morbidity and mortality.3,8 Many patients will develop symptoms that are refractory to medical therapy, either after a period of long-term medical therapy or during the first presentation of acute heart failure It is in these patients that placement of a VAD is considered Decisions about the timing of VAD placement can be among the most challenging in caring for children with advanced heart failure, but there is growing evidence that earlier placement, before the patients are in shock with multiorgan system failure, leads to improved outcomes.4,9 In the most recent annual report from Pedimacs, a large North American registry of pediatric VAD patients, patients who were Pedimacs profile 1 (critical cardiogenic shock) at the time of VAD implant had significantly inferior survival compared with those that were less ill at the time of VAD implant (Fig 66.1) Additional major morbidities that can complicate heart failure include respiratory failure, renal insufficiency, liver dysfunction, and malnutrition/growth failure These major morbidities are also associated with outcome after VAD implantation Data from INTERMACS, a large registry of adult VAD patients, evaluating more than 10,000 adult patients, found that preoperative morbidity, including being on a ventilator and having an elevated bilirubin level, a lower albumin level, and renal insufficiency, are associated with a significantly greater risk of death after VAD implantation.10 Unfortunately, these morbidities are common in children, with 31% Pedimacs profile 1, nearly 50% intubated, and 35% dependent on total parental nutrition at time of VAD implantation.4 Fortunately, much of the endorgan dysfunction, growth failure, and debilitated condition of many patients can be reversed after VAD placement and prior to heart transplantation and VAD explant.11,12 Indeed, the outcome after transplantation among patients supported with VADs is equivalent to patients who come to transplant on medical therapy alone.2 This would almost certainly not be the case if patients were transplanted in cardiogenic shock or multiorgan system dysfunction, as is frequently the case for VAD implantation.13 FIG 66.1 Overall survival stratified by severity of illness at the time of implant as categorized by INTERMACS patient profile (Modified from Blume ED, VanderPluym C, Lorts A, et al Second annual Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) report: pre-implant characteristics and outcomes J Heart Lung Transplant 2018;37[1]:38–45.) There is neither widespread agreement nor evidence-based guidelines on the optimal timing for placement of VADs in children The International Society for Heart and Lung Transplantation published consensus guidelines for MCS in 2013 and recommended that long-term VADs be considered for patients whose ventricular function is unlikely to recover without long-term support, who are inotrope dependent, too ill to maintain normal hemodynamics and organ function without temporary mechanical support or inotropes, who have the capacity for meaningful recovery of end-organ function and quality of life, and who have a high risk of 1-year mortality without VAD support.14 These are also reasonable guidelines for children, although clearly more data are needed to help understand the optimal time of VAD placement Support Strategies The vast majority of pediatric patients are placed on long-term MCS as a bridge to transplantation.15 Among 109 patients supported with continuous flow (CF) durable VADs reported to Pedimacs, only six had their VAD implanted as destination therapy (i.e., VAD implant with no plan to list for heart transplantation).16 This is in contradistinction to adult VAD patients, where nearly 50% of patients are currently implanted either as destination therapy or where a bridge to transplant is deemed unlikely.10 The use of VADs for destination therapy has been performed in some populations such as neuromuscular disease and will likely represent a growing support strategy in children over the next decade.17,18 Myocardial recovery and successful VAD explant without transplantation is uncommon with long-term MCS, especially outside of myocarditis.15,16,19 ... implant as categorized by INTERMACS patient profile (Modified from Blume ED, VanderPluym C, Lorts A, et al Second annual Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) report: pre-implant characteristics and outcomes... guidelines for children, although clearly more data are needed to help understand the optimal time of VAD placement Support Strategies The vast majority of pediatric patients are placed on long-term MCS as a bridge to transplantation.15 Among 109 patients supported with continuous flow (CF)