CT Coronary Angiography and Dynamic CT Myocardial Perfusion for Detection of Cardiac Allograft Vasculopathy

BackgroundCardiac allograft vasculopathy (CAV) is a major obstacle limiting long-term graft survival. Effective noninvasive surveillance modalities reflecting both coronary artery and microvascular components of CAV are needed.ObjectivesThe authors evaluated the diagnostic performance of dynamic computed tomography–myocardial perfusion imaging (CT-MPI) and coronary computed tomography angiography (CCTA) for CAV.MethodsA total of 63 heart transplantation patients underwent combined CT-MPI and CCTA plus invasive coronary angiography (ICA) with intravascular ultrasonography (IVUS) between December 2018 and October 2021. The median interval between CT-MPI and heart transplantation was 4.3 years. Peak myocardial blood flow (MBF) of the whole myocardium (MBF_global) and minimum MBF (MBF_min) among the 16 segments according to the American Heart Association model, except the left ventricular apex, were calculated from CT-MPI. CCTA was assessed qualitatively, and the degree of coronary artery stenosis was recorded. CAV was diagnosed based on both ICA (ISHLT criteria) and IVUS. Patients were followed up for a median time of 2.3 years after CT-MPI and a median time of 5.7 years after transplantation.ResultsAmong the 63 recipients, 35 (55.6%) had diagnoses of CAV. The median MBF_global and MBF_min were significantly lower in patients with CAV (128.7 vs 150.4 mL/100 mL/min; P = 0.014; and 96.9 vs 122.8 mL/100 mL/min; P < 0.001, respectively). The combined use of coronary artery stenosis on CCTA and MBF_min showed the highest diagnostic performance with an area under the curve of 0.886 (sensitivity: 74.3%, specificity: 96.4%, positive predictive value: 96.3%, and negative predictive value: 75.0%).ConclusionsThe combination of CT-MPI and CCTA demonstrated excellent diagnostic performance for the detection of CAV. One-stop evaluation of the coronary artery and microvascular components involved in CAV using combined CCTA and CT-MPI may be a potent noninvasive screening method for early detection of CAV.     

The Presentation and Diagnosis of Coronary Allograft Vasculopathy in Pediatric Heart Transplant Recipients

One of the most important causes for long‐term graft failure in pediatric heart transplant recipients is coronary allograft vasculopathy (CAV). Graft survival is approximately 50% at 5 years postdiagnosis of CAV. CAV can be difficult to detect largely because of its variability in presentation and in the definition of CAV. Making the diagnosis of CAV can be challenging, and to date, the current gold standard test is angiography, which is an expensive and invasive procedure. A number of studies in the pediatric and adult heart transplant literature exist for noninvasive methods of diagnosing CAV, ranging from biochemical markers and echocardiographic techniques to computed tomography and magnetic resonance imaging. In addition, there is evidence to show that hemodynamic and function evaluation of the coronary arteries in transplanted patients may provide diagnostic clues to the potential development of CAV. These methodologies add to the armamentarium that can compliment angiography for the purposes of diagnosis. Clinical suspicion for CAV should be heightened in patients who have had recurrent rejection, new onset arrhythmias, unexplained recurrent chest or abdominal pain, and/or the development of systolic or diastolic dysfunction in the absence of rejection. This review strives to highlight the current literature with respect to the investigations available for the diagnosis of CAV, recognizing that our understanding of this disease process is still currently in evolution.     

双源CT冠状动脉血管成像对单支冠状动脉变异的诊断价值

目的分析评价双源CT冠状动脉血管成像对成人单支冠状动脉的诊断价值。方法收集本院37980例行双源CT冠状动脉造影的患者检查资料,回顾性分析单支冠状动脉变异情况。结果 37980例冠状动脉血管成像(CTA)中,共检测出单支冠状动脉26例,检出率约为0.07%,其中男13例,女13例,平均年龄(62.23±13.47)岁。检测出单支冠状动脉类型包括LI型8例,RI型1例,LII A型4例,LII B型2例,RII A型7例,RII B型2例,RII P型2例。结论 CTA能准确评价单支冠状动脉变异及各种亚型情况,对临床干预及治疗具有重要指导作用。     

Coronary Vasospasm Following Heart Transplantation: Rapid Progression to Aggressive Cardiac Allograft Vasculopathy

Coronary artery vasospasm (CVS) has been described in orthotopic heart transplant patients but is rare in the post-transplanted, denervated heart. Severe CVS has been associated with accelerated cardiac allograft vasculopathy (CAV) and allograft rejection. Allograft vasculopathy is the leading cause of decreased long-term survival in orthotopic heart transplant. The prognostic significance and relationship of the presence and severity of CVS with CAV are not well understood. We present a case of severe symptomatic CVS with rapid development of severe CAV. Our case emphasizes the need for close angiographic surveillance and intracoronary imaging for early detection of CAV in the presence of vasospasm.     

Bidirectional Ventricular Tachycardia Due to Coronary Allograft Vasculopathy a Unique Presentation

Bidirectional ventricular tachycardia (BVT) is an uncommon type of polymorphic ventricular tachycardia (PVT) with alternating polarity of the QRS complex most commonly described digitalis toxicity. Recent data has demonstrated the possible molecular basis of this electrocardiographic phenomenon. To our knowledge this is the first reported case of BVT in a patient with orthotopic cardiac transplantation and coronary allograft vasculopathy.     

Cinacalcet in Pediatric and Adolescent Chronic Kidney Disease: A Single-Center Experience

Cinacalcet, a calcimimetic drug, has been shown to be efficacious in adult chronic kidney disease (CKD) patients; however, it was not fully studied in pediatric CKD patients. We aimed at assessing the effect of cinacalcet on intact parathyroid hormone (iPTH) secretion in children with CKD-4/5 with iPTH consistently ≥ 300 pg/mL refractory to conventional treatment.This is a prospective cohort analysis of 28 children with uncontrolled hyper-parathyroidism secondary to stage 4 and 5 CKD admitted to a tertiary center during the period from April 2012 to April 2014.Twenty-eight patients with CKD-4/5 were assessed prospectively regarding bone biochemistry, renal ultrasonography, serum iPTH level, and medications. Patients were classified into 3 groups: group 1, 6 patients with CKD-4 on supplemental and supportive therapy; group 2, 6 patients with CKD-5 on hemodialysis and; group 3, 16 patients with CKD-5 on automated peritoneal dialysis. Patients were between the ages of 9 months and 18 years on commencing cinacalcet at doses of 0.5 to 1.5 mg/kg.All patients showed at least a 60% reduction in iPTH (60%–97%). Highly significant reduction in iPTH and serum alkaline phosphatase levels was detected post-cinacalcet. The serum calcium (Ca), phosphate (P), and Ca × P product were unaffected. Treatment was well tolerated with no hypophosphatemia, hypocalcemia, or other adverse effects almost in all patients.Cinacalcet use was proven safe for all pediatric and adolescent patients with CKD-4/5 during the study period, and at the same time most of the patients reached the suggested iPTH target values     

Endothelial Dysfunction and Cardiac Allograft Vasculopathy

Cardiac allograft vasculopathy remains a major challenge to long-term survival after heart transplantation. Endothelial injury and dysfunction, as a result of multifactorial immunologic and nonimmunologic insults in the donor and the recipient, are prevalent early after transplant and may be precursors to overt cardiac allograft vasculopathy. Current strategies for managing cardiac allograft vasculopathy, however, rely on the identification and treatment of established disease. Improved understanding of mechanisms leading to endothelial dysfunction in heart transplant recipients may provide the foundation for the development of sensitive screening techniques and preventive therapies.     

Multidisciplinary Management of Pediatric Hepatoblastoma: A 20-Year Single-Center Experience

Background:Hepatoblastoma is rare cancer that responds well to risk-based chemotherapy, and surgical treatment is needed to achieve complete remission and satisfactory survival rates in hepatoblastoma patients. In this study, we evaluated the clinical features and treatment outcomes of pediatric hepatoblastoma patients treated in our clinic.Methods:Eighteen patients with hepatoblastoma who were treated and followed up in our center between June 1999 and June 2020 were analyzed retrospectively. All patients were evaluated by a multidisciplinary team and managed using a risk-based protocol (SIOPEL-1 and SIOPEL-3).Results:The patients’ mean age at diagnosis was 38.33 ± 52.34 months. Sixteen patients (89%) received neoadjuvant chemotherapy, and 2 patients (11%) who underwent complete mass excision at diagnosis received adjuvant chemotherapy. After neoadjuvant therapy, the tumor was completely resected in 8 patients (45%), while liver transplantation was performed in 6 patients (34%) because complete resection of the tumor was not possible. Two patients died before surgical treatment. One patient relapsed with lung metastasis after salvage chemotherapy. She is alive without disease at 64 months. The mean follow-up time was 59.3 ± 49.8 months; 5-year overall and disease-free survival rates were 88.9% and 80.8%, respectively. The 5-year overall survival rate was 100% for both liver transplant and resected patients, whereas 5-year disease-free survival was lower in transplant patients (75% vs 100%, P < .001).Conclusion:Multidisciplinary follow-up is especially important for patients who may need liver transplantation. Some patients may benefit from new treatment options such as radiofrequency ablation and cyberknife treatment.     

Radiation Dose Reduction in CT Coronary Angiography

During recent years, technologic advancements in computed tomography (CT) have allowed robust cardiac and coronary imaging. Small, mobile cardiac structures such as the coronary arteries can now be imaged directly and noninvasively with high precision. Given the fact that coronary CT angiography (CCTA) can detect preclinical calcified and noncalcified atherosclerosis, there is potential to revolutionize the management of ischemic heart disease by refining risk stratification and improving outcomes in various clinical settings. However, despite this progress, CT has come under scrutiny as concerns about the level and risk of the radiation exposure of the population grow. Although there are no data to support a direct association between CT imaging and risk of future cancer, health care practitioners should make every effort to minimize radiation exposure to their patients. The purpose of this article is to describe techniques that can reduce radiation dose to patients during CCTA but maintain diagnostic image quality.     

Plasmapheresis and Intravenous Immunoglobulin in Early Antibody-Mediated Rejection of the Renal Allograft: A Single-Center Experience

Antibody-mediated rejection (AMR) is a rare complication which often results in the loss of the kidney graft. The objective of this retrospective single center study was to evaluate two different approaches to AMR. We retrospectively evaluated data files from 936 patients who had undergone renal transplantation in 2002–2006. In 2002–2003, patients with AMR were treated with five plasmapheresis sessions (PP group, N = 13), and in 2004–2006 they received five plasmapheresis session along with intravenous immunoglobulin 0.5 g/kg (PP+IVIg group, N = 11). Twelve months of follow-up data was analyzed. First year graft survival was significantly higher in the PP+IVIg group than in the PP group (90.9% vs. 46.2%; P = 0.044); similarly, patient survival was higher in the PP+IVIg group (100% vs. 76.9%; P = 0.056). The incidence of infectious complications was similar in both groups. In re-biopsies, patients in the PP group often suffered from cellular rejection. The deposition of C4d complement was similar in re-biopsies in both groups. In this large single center study we proved the superiority of plasmapheresis with intravenous immunoglobulin administration in the treatment of early AMR of renal allografts.