Weia Benjamin C, Adachi Iki, Jacot Jeffrey G
Department of Bioengineering, Rice University, Houston, TX, USA.
Congenital Heart Surgery, Texas Children's Hospital, Houston, TX, USA.
Artif Organs. 2015 Aug;39(8):691-700. doi: 10.1111/aor.12451. Epub 2015 Apr 10.
Ventricular assist device (VAD) support induces reverse remodeling of failing myocardium that leads to occasional functional recovery of the adult heart. While there have been numerous clinical reports in adult patients with end-stage cardiomyopathy, little is known about reverse remodeling in children, which has increasing clinical potential with the recent expansion of pediatric VADs in the setting of static organ supply for heart transplantation. Pediatric myocardium also promises theoretical advantages for recovery over adult myocardium due to its greater abundance of cardiac progenitor cells. To identify potential targets of future studies, we conducted a literature review with two aims: (i) to summarize clinical cases of pediatric patients who exhibited cardiac recovery following VAD support; and (ii) to analyze genetic changes in pediatric myocardium induced by VAD support compared with those observed in adult patients. Several clinical series of pediatric VAD cases report that small proportions of their cohorts were weaned off from device support, but a lack of information about the etiology and support duration of these patients limits the ability to determine whether they represent reverse remodeling of myocardial structure or just recovery from acute illness. A comparison of pediatric and adult gene expression changes with VAD support reveals approximately 40% of genes to be oppositely regulated, indicating that the pediatric genetic response is distinct. These observations highlight a necessity to better understand reverse remodeling specific to pediatric myocardium, which is crucial to improving clinical strategies for bridge-to-recovery in children.
心室辅助装置（VAD）支持可诱导衰竭心肌发生逆向重构，从而使成年心脏偶尔实现功能恢复。虽然成年终末期心肌病患者已有大量临床报告，但对于儿童逆向重构的了解却很少。鉴于在心脏移植供体器官供应不变的情况下，小儿VAD最近有所增加，儿童逆向重构具有越来越大的临床潜力。由于小儿心肌中富含更多的心脏祖细胞，因此在恢复方面比成人心肌具有理论优势。为了确定未来研究的潜在靶点，我们进行了一项文献综述，目的有两个：（i）总结VAD支持后出现心脏恢复的儿科患者的临床病例；（ii）分析VAD支持诱导的小儿心肌基因变化，并与成年患者中观察到的基因变化进行比较。几个小儿VAD病例的临床系列报告称，他们队列中的一小部分患者撤掉了装置支持，但缺乏这些患者的病因和支持持续时间的信息，限制了确定他们是否代表心肌结构的逆向重构或只是从急性疾病中恢复的能力。对VAD支持下小儿和成人基因表达变化的比较显示，约40%的基因受到相反调控，这表明小儿的基因反应是不同的。这些观察结果凸显了更好地了解小儿心肌特异性逆向重构的必要性，这对于改进儿童桥接恢复的临床策略至关重要。
