Randomized Trial of Pulmonary Valve Replacement in TOF

慢性肺反流（PR）是法洛四联症（TOF）修复术后长期存活患者发病和死亡的重要原因。尽管早期结果表明，在修复性TOF和严重PR患者中进行肺动脉瓣置换术（PVR）的死亡率非常低，但我们和其他研究者的数据表明，尽管成功地恢复了肺动脉瓣功能并消除了右心室容量过载，右心室功能障碍仍然存在甚至恶化。我们假设，在TOF修复的长期幸存者中，动脉瘤性和不动性的右心室壁段的持续存在导致了持续的右心室功能障碍，而PVR并不能单独解决这些问题。这项前瞻性、随机、单中心试验旨在比较两种手术策略，单独PVR（标准治疗）与PVR +手术性右心室重塑对修复性TOF和慢性PR患者右心室力学的影响。根据标准化的术前定量心脏MRI标准符合入组条件的患者将被随机分配到单独PVR或PVR +手术性右心室重塑组。在两个研究组中，患者将在肺位置接受生物假体瓣膜（标准治疗）。在PVR + RV重塑组中，动脉瘤性和RV自由壁的动力学部分将被切除，以减少RV和PVR的大小。第一个具体目的是比较两种手术策略在术后6个月对RV力学的影响。主要结局变量是通过心脏MRI测量的术后6个月左室射血分数与术前比较的变化。次要结局变量是左室和左室容积、质量、质量容积比、可恢复的心室卒中容积和射血量的变化

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.