Clinical Research Directory

Investigation of Tetralogy of Fallot in Neonates

Child health serves as the foundation for overall public health, with neonatal mortality recognized globally as a comprehensive indicator of national health standards and societal advancement. The Healthy Children Action Improvement Plan (2021-2025) sets a national target to reduce neonatal mortality in China to below 3.1‰. Congenital heart disease (CHD), the most prevalent congenital defect among neonates, constitutes a significant cause of disability and premature death in the Chinese population. Annually, approximately 70,000-80,000 neonates are born with CHD, among whom nearly 10,000 present with critical congenital heart disease (CCHD). Postnatal manifestations of CCHD often include cyanosis, hypoperfusion, and respiratory distress, with untreated cases resulting in approximately 50% mortality. CCHD is one of the leading causes of infant death. Tetralogy of Fallot (TOF), the most common form of CCHD, accounts for a substantial proportion of cyanotic congenital heart diseases. It is characterized by four anatomical abnormalities: ventricular septal defect, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy. These structural defects disrupt intracardiac blood flow, reduce arterial oxygen saturation, and result in cyanosis and other related symptoms. Untreated TOF leads to significant health issues early in life, including growth retardation, recurrent hypoxic episodes, heart failure, and increased susceptibility to infections. Long-term survival is markedly reduced, with only a small proportion surviving into adulthood. Thus, surgical intervention is pivotal for improving outcomes in TOF(Tetralogy of Fallot) patients. Despite advances in medical technology yielding satisfactory early outcomes, long-term prognosis following TOF correction remains a challenge. Historically, surgical strategies emphasized complete relief of right ventricular outflow tract obstruction, often at the expense of pulmonary valve function. Recent studies, however, highlight the critical role of preserving pulmonary valve function in improving long-term outcomes, as pulmonary valve dysfunction is a leading cause of late right ventricular failure and reintervention. Additionally, surgical approaches, whether via atrial or ventricular access, have inherent advantages and limitations, but neither can fully eliminate the risk of postoperative arrhythmias associated with TOF's anatomical complexity and surgical impact. These issues underscore the necessity for further advancements in long-term management strategies. Surgical correction of TOF in a single-stage procedure has become standard practice, with the timing of surgery progressively shifting to earlier ages-from school age in the 1990s to the current standard of 3-6 months of age. This timing ensures sufficient weight and organ maturity to withstand the complexities of cardiac surgery. However, in clinical practice, significant challenges persist, including: (1) Deterioration during the waiting period, during which patients may experience recurrent hypoxic episodes, inadequate weight gain, and exacerbated pulmonary vascular underdevelopment, thereby complicating definitive surgery and increasing perioperative risk. (2) Developmental delays due to chronic hypoxemia and heart failure, potentially leading to neurological deficits and pulmonary hypertension, adversely affecting cognitive and motor development. Neonatal repair, performed within 28 days of life, may mitigate these challenges by restoring normal circulatory physiology at the earliest possible stage. International guidelines endorse neonatal TOF repair for capable centers, citing the potential for enhanced clinical benefits and superior prognoses. Clinical observations at our center indicate several advantages of neonatal TOF repair, including reduced intraoperative bleeding, cleaner surgical fields, and better pulmonary vascular development. These benefits may be attributed to the regenerative potential of neonatal myocardial cells and the absence of prolonged pathological circulatory states, which otherwise exacerbate anatomical abnormalities. Early intervention may reduce right ventricular fibrosis and pulmonary vascular pathology, thereby improving long-term outcomes. With advancements in surgical techniques and perioperative care, neonatal TOF repair has become a routine practice at our center, with over 100 cases performed annually for two consecutive years. This success is supported by an integrated prenatal-to-postnatal care model, establishing a comprehensive treatment framework. Given this context, the investigators propose a multicenter, randomized controlled trial (RCT) to compare the safety and efficacy of neonatal and infant TOF repair. This study aims to provide high-quality evidence for clinical practice, determine optimal surgical timing, and enhance overall survival rates and quality of life for TOF patients.

An Integrated Prenatal and Postnatal Treatment Model for the Treatment of Newborns With Critical Congenital Heart Disease

The purpose of this two-way cohort study was to explore whether an integrated prenatal and postnatal treatment model for neonates with critical congenital heart disease (CCHD) could be effective in avoiding preoperative morbidities, creating an ideal timing for surgery, thereby reducing postoperative in-hospital mortality, and improving surgical prognosis compared with the traditional model of care. In addition, in neonates with CCHD associated with the right cardiac system, the investigators aim to further investigate whether early postnatal cardiac surgery has the potential advantage of obtaining a time window for myocardial regeneration and thus improving myocardial remodeling. The aim of this study is to improve the diagnostic and therapeutic capacity of critical congenital heart disease and to promote the integrated prenatal-postnatal treatment model for clinical use. This will ultimately improve the quality of healthcare services for patients with cardiovascular diseases and lay the foundation for exploring guidelines for the treatment of cardiovascular diseases suitable for China's national conditions. The project will be jointly implemented by Beijing Anzhen Hospital , Capital Pediatric Research Institute, and 307 PLA General Hospital. Starting from January 1, 2022, the hospitals will continue to collect hospitalized cases of newborns with CCHD. The integrated prenatal and postnatal model is defined as a definitive diagnosis of CCHD in the fetal period (22-26 weeks), documentation of intrauterine transfer in our obstetrics department, subsequent initiation of an intrapartum or postpartum surgical plan after multidisciplinary consultation, and transfer to the pediatric heart center at the first hour of life, where the child is treated with either postpartum immediate or elective surgery, depending on patient status. For neonates who meet the indications for emergency surgery, surgery is performed immediately after birth. For neonates with non-emergency surgical indications, surgery is performed after birth adjustment to optimal status. The traditional model was defined as postpartum transfer via an outside hospital with routine interventions. The investigators then evaluate surgical prognosis and myocardial regenerative capacity to compare the effects of the two treatment models. This project will validate the advantages of an integrated prenatal and postnatal model over traditional models through real-world research and will improve prognosis in neonates with CCHD.

MASA Valve Early Feasibility Study

The MASA Valve Early Feasibility Study (MVEFS) multi-site interventional clinical trial within the United States of America with each center following a common protocol.The objective of the trial is to evaluate the safety and probable benefit of MASA Valve in the indicated subset of patients requiring Right Ventricular Outflow Tract Reconstruction (RVOTR). As an early feasibility study, the purpose is determine the feasibility of success of the device in order to gather early data towards a future pivotal study and/or regulatory clearance submission.