Randomized Trial of Pulmonary Valve Replacement in TOF

慢性肺返流(PR)是法洛四联症(TOF)修补术长期存活者发病率和死亡率的重要原因。尽管修复的TOF和严重PR患者接受肺瓣膜置换术(PVR)的早期结果表明，手术与非常低的死亡率相关，但我们和其他研究人员的数据表明，尽管成功地恢复了肺动脉瓣功能，消除了RV容量过载，但RV功能障碍经常持续甚至恶化。我们假设，在TOF修复的长期幸存者中，动脉瘤样和无运动的房室壁节段的持续存在，而这些节段不能单独通过PVR处理，导致持续的RV功能障碍。这项前瞻性、随机、单中心试验旨在比较单纯PVR(标准治疗)与PVR和外科RV重塑两种手术策略对修复性TOF和慢性PR患者RV力学的影响。根据标准化的术前定量心脏MRI标准，符合登记条件的患者将被随机分配到单纯PVR组或PVR和外科RV重建组。在这两项研究中，患者将接受肺位的生物瓣膜(标准治疗)。在PVR+RV重塑组，除PVR外，还将切除RV游离壁的动脉瘤和静止部分，以缩小RV的大小。第一个具体目标是比较两种手术策略对术后6个月RV力学的影响。主要结果变量是心脏MRI测量的右室射血分数在术后6个月与术前相比的变化。次要结果变量是右室和左室容量、质量、质量/体积比以及可招募的每搏量和射血。 测量6个月时对亚极量多巴酚丁胺应激反应的分数(心脏核磁共振) 术后与术前比较。其他次要结果变量包括功能状态评分(SF-36)、运动能力(跑步机测试)、肺功能以及对心律失常和传导的全面无创性评估。第二个具体目的是比较PVR加外科RV重建组和单纯PVR组术后不良事件的发生率。总样本量为100名患者，将在四年内招募。

Chronic pulmonary regurgitation (PR) is an important cause of morbidity and mortality in long-term survivors of tetralogy of Fallot (TOF) repair. Although early results of pulmonary valve replacement (PVR) in patients with repaired TOF and severe PR have demonstrated that surgery is associated with very low mortality, our data and that of other investigators have demonstrated that despite successful restoration of pulmonary valve competence and elimination of the RV volume overload, RV dysfunction often persists or even worsens. We hypothesize that persistence of aneurysmal and akinetic RV wall segments, which are not addressed by PVR alone, contribute to persistent RV dysfunction in long-term survivors of TOF repair. This prospective, randomized, single-center trial aims to compare the effects of two surgical strategies, PVR alone (standard treatment) vs. PVR and surgical RV remodeling, on RV mechanics in patients with repaired TOF and chronic PR. Patients who are eligible for enrollment based on standardized preoperative quantitative cardiac MRI criteria will be randomly assigned to PVR alone or to PVR and surgical RV remodeling. In both study arms patients will receive a bioprosthetic valve in the pulmonary position (standard treatment). In the PVR + RV remodeling group, the aneurysmal and akinetic portions of the RV free wall will be resected to reduce RV size in addition to PVR. The first specific aim is to compare the effects of the two surgical strategies on RV mechanics six months after surgery. The primary outcome variable is the change in RV ejection fraction six months postoperatively compared with preoperatively as measured by cardiac MRI. Secondary outcome variables are changes in RV and LV volumes, mass, mass-to-volume ratio, and recruitable ventricular stroke volume and ejection fraction in response to submaximal Dobutamine stress (by cardiac MRI) measured six months postoperatively compared with preoperative values. Other secondary outcome variables include a functional status score (SF-36), exercise capacity (treadmill test), pulmonary function, and a comprehensive noninvasive assessment of arrhythmias and conduction. The second specific aim is to compare the incidence of postoperative adverse events occurring in the PVR plus surgical RV remodeling group to those in the PVR alone group. The total sample size is 100 patients, to be recruited over four years.