In February 2011, a 16 year old male with Becker muscular dystrophy (BMD) and associated dilated cardiomyopathy was referred to our institution for heart transplant evaluation. At the time of presentation, he was able to ambulate for up to 15 minutes, but required multiple naps during the day and was no longer able to attend school. He was only able to eat small meals two to three times per day without emesis. Prealbumin level was 11 mg/dl, consistent with malnutrition. Echo showed left ventricular end-diastolic dimension of 6.2 cm (z score 3.2) and ejection fraction of 30%. Cardiac catheterization revealed an indexed pulmonary vascular resistance (PVR) of 17 Wood units (WU) and left ventricular end-diastolic pressure of 35 mm Hg. His heart failure worsened, and he required milrinone, dopamine, and positive pressure ventilation for hemodynamic support. Because of pulmonary hypertension, he was declined for immediate transplant listing. On March 10, 2011, a Thoratec HeartMate II (Thoratec Corporation, Pleasanton, CA) left ventricular assist device was placed as bridge to decision pending improvement in PVR. He was discharged on postoperative day 38. At repeat cardiac catheterization 3 months later, PVR was 2.9 WU. The option of transplant listing was discussed with the patient and his family, but the patient elected to continue as destination therapy. He reported feeling comfortable with his current situation and had significant anxiety associated with transplant.
At the time of VAD implant, the patient weighed 47.6 kg (body mass index [BMI] 20 kg/m2, body surface area [BSA] 1.47 m2). He demonstrated dramatic weight gain soon after VAD implant and currently weighs 74.4 kg (BMI 28 kg/m2, BSA 1.84 m2). His mobility declined after VAD implant and worsened after a patellar fracture 6 months after implant. Although he is now nonambulatory and wheelchair-dependent, his overall skeletal weakness has not progressed significantly, and he remains able to handle his VAD controller and change batteries unassisted. He has graduated from high school, lives at home with his family, and works part-time job with his family’s videography business. He reports good mood and good quality of life (QOL).
Cardiology follow-up now entails twice monthly laboratory monitoring and clinic visits every 3 months with echocardiograms. Anticoagulation is maintained with warfarin, clopidogrel, and aspirin. Listing for heart transplant has been discussed at frequent intervals, as his underlying muscular dystrophy with loss of ambulation is not an absolute contraindication to transplant at our institution. However, he has chosen to continue as destination therapy citing contentment with his current QOL. He has been rehospitalized nine times over more than 5+ years of VAD support (Table 1) for a total of 71 days in hospital since initial discharge after VAD placement. Because of his BMD, he has continued to receive multidisciplinary follow-up with pulmonary, psychiatric, and neuromuscular specialists.
This case highlights several aspects of long-term VAD support in pediatric patients. First, we show that long-term pediatric VAD support is feasible, and to our knowledge, this is one of the longest durations of pediatric VAD support reported. The longest follow-up time reported in the first Pediatric Interagency Registry for Mechanical Circulatory Support (PediMACS) analysis published in 2016 was 28 months; however, enrollment in PediMACs only began in September 2012.1 There have been a few other published cases of long-term pediatric VAD support. A 2015 multicenter report by Schweiger et al.2 noted one pediatric patient on destination VAD therapy with a HeartWare VAD for 845 days. Perri et al.3 recently reported on six pediatric patients in Italy implanted as destination therapy with the Jarvik 2000 VAD; their longest duration of support was 1344 days before death from lung infection. As an adolescent, our patient’s BSA at time of implant was similar to smaller adults; a recent Interagency Registry for Mechanically Assisted Circulatory Support study reviewed outcomes of continuous flow VADs in adults with BSA < 1.5 m2, but the duration of support was not reported.4 Although there may be unreported cases of smaller adults supported for longer duration, this case highlights unique pediatric-specific long-term VAD support issues, including psychosocial concerns, school reintegration, and the transition of medical decision-making from parents to young adults.
Second, this case highlights the fluid boundary between VAD support as bridge to transplant and destination therapy. Transplant re-evaluation has been offered multiple times over the years, and both the patient and his family continue to prefer VAD therapy, citing contentment with his current QOL. There are few studies on QOL in pediatric VAD patients. Miller and colleagues5 administered the Pediatric Quality of Life Inventory to 13 pediatric patients at a median 1.6 months of VAD support (longest 19.7 months). Overall QOL scores were significantly lower than healthy controls subjects, post-transplant patients, and patients with severe heart disease. This is in contrast to QOL studies in adult VAD patients, where QOL has been consistently shown to improve postimplant.6,7 As more pediatric patients receive VAD therapy and as duration of VAD support increases for pediatric patients, further studies on QOL in pediatric VAD patients are needed.
Additionally, this case highlights the successful management of adverse events on long-term VAD therapy in a patient with muscular dystrophy. A previous report by Ryan et al.8 focused on adverse events early after VAD implantation.8 PediMACS data show that at 12 months postimplant, 57% of pediatric VAD patients experienced at least one significant adverse event (defined as device malfunction, infection, major bleeding, and neurologic dysfunction).9 Rehospitalization was also very common, occurring in 61% of discharged patients.10 All adverse events experienced by this patient occurred without any hemodynamic or respiratory compromise, including an 11 second episode of pump stoppage occurring at home because of a short circuit in the driveline lead. Notably, there have been no issues with pump thrombosis or significant bleeding.
Specifically for patients with muscular dystrophy on VAD support, Seguchi and colleagues11 reported stable or improved skeletal muscle function in their patients with muscular dystrophy after VAD implantation, whereas an earlier report from our institution highlighted weight gain and loss of ambulation in patients with muscular dystrophy.12 Despite the weight gain and loss of ambulation for our patient, he has not experienced adverse events with significant hemodynamic compromise.
Lastly, this case highlights some unique challenges of long-term VAD therapy in pediatric patients. This patient celebrated his 18th birthday while on VAD therapy, and as his own legal medical guardian, he completed an advanced directive to help guide his subsequent care. Palliative care services were introduced to the family early in his course; introduction of the concept of palliative care early in VAD therapy allows families time to think about possibilities if complications arise and also normalizes the conversation regarding end-of-life care. This has also allowed for a frank discussion of a plan for VAD deactivation if death (anticipated or unexpected) occurs at home.
In summary, successful long-term support of a pediatric VAD patient with muscular dystrophy is feasible. Further studies on QOL and weight management in pediatric VAD patients are warranted as support time increases.
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