This year saw exciting developments in the treatment of pediatric and congenital heart disease (CHD). Transcatheter pulmonary valve replacement (TPVR) continued to dominate the field of interventional cardiology, with data now showing good short-term outcomes for self-expanding transcatheter pulmonary valves (TPVs), with improved survival rates for patients with tetralogy of Fallot (TOF) undergoing pulmonary valve replacement (PVR). Two interesting topics have been revisited: comparison of hybrid versus nonhybrid surgical palliation for patients with single ventricles, and high-risk postoperative characteristics of anomalous origins of the coronary arteries.

Short-Term Outcomes of the Harmony TPV System at 1 Year Are Encouraging

TPVR in patients with native right ventricular (RV) outflow tracts is important to the CHD community. The Harmony TPV System (Medtronic, Minneapolis, Minnesota) is one of two valves approved by the Food and Drug Administration (FDA) for TPVR in the native outflow tract. Three studies of the self-expanding Harmony TPVR valve were pooled to create the largest-to-date cohort of patients receiving the Harmony TPVR valve in this prospective study.¹ The primary endpoint was freedom from procedure-related or device-related mortality. The primary efficacy endpoint was freedom from pulmonary regurgitation (moderate or worse), pulmonary stenosis (RV outflow gradient >40 mm Hg), and need for reintervention (device-related reoperation or transcatheter reintervention). Other secondary efficacy endpoints were also included.

The valve comes in two sizes: 22 mm (TPV 22) and 25 mm (TPV 25). The study included 87 patients, with close to half (n = 42 [48%]) undergoing a TPV 22 valve placement and the remaining (n = 45 [52%]) undergoing TPV 25 valve placement. There were no deaths throughout the 1-year follow-up period, indicating excellent short-term safety outcomes. Short-term efficacy was also excellent, with 98% of patients receiving the TPV 22 and 100% of patients receiving the TPV 25 being free from regurgitation, stenosis, and reintervention.

Comparison of Hybrid vs. Nonhybrid Surgical Strategies for Patients With Single Ventricles

The Congenital Heart Surgeons' Society's (CHSS) critical left heart obstruction cohort was a multi-institutional study of infants with critical left heart obstruction that compared hybrid management (bilateral pulmonary artery banding with or without ductal stenting) versus nonhybrid management (Norwood, primary transplantation, biventricular [BiV] repair, transcatheter/surgical aortic valvotomy) strategies.² From 2005 to 2019, 1,045 infants across 28 institutions were included. The primary endpoint was survival.

Hybrid palliation was performed in 214 infants (20%), including ductal stenting in 148 (69%). Nonhybrid management strategies were performed in 831 infants (80%), including Norwood operation in 684 (82%), transcatheter balloon aortic valvotomy in 83 (10%), BiV surgical repair in 54 (6%), primary transplantation in 5 (0.6%), and atrial septal intervention with subsequent death in 5 (0.6%).

Infants undergoing hybrid palliation had lower birth weight, smaller gestational age, and higher prevalence of in utero interventions, noncardiac comorbidities, preoperative mechanical ventilation, absent interatrial communication, and moderate or severe mitral valve stenosis (p < 0.03 for all variables). The unadjusted 12-year survival rate after hybrid management was 55% and after nonhybrid management was 69%. After matching, the 12-year survival rate after hybrid management was 58% and after nonhybrid management was 63% (p = 0.37). Among matched infants born weighing <2.5 kg, the 2-year survival rate after hybrid management was 37% and after nonhybrid management was 51% (p = 0.22).

The investigators concluded that infants born with critical left heart obstruction undergoing hybrid palliation have more high-risk characteristics and anatomy than do infants undergoing nonhybrid palliation. After adjustment, there was no significant difference in 12-year survival rates between hybrid and nonhybrid management. Mortality rates remained high, and hybrid palliation conferred no survival advantage, even for infants with lower birth weight (<2.5 kg).

Identifying Incidence of High-Risk Postoperative Anatomical Features on Computed Tomographic Angiography Following Repair of Anomalous Aortic Origin of a Coronary Artery

In a study of 62 patients reported by Doan et al., the preferred surgical procedure was unroofing of the intramural course (45 patients [73%]) versus transection and reimplantation (TAR; 17 patients [27%]).³ The high-risk anatomical features evaluated 3 months after the index surgery were residual acute-angle takeoff, intramural course, thickened intercoronary pillar, slit-like ostium, and interarterial course.

After unroofing, most common residual lesions included residual acute-angle takeoff (100% of patients), interarterial course (78%), and coronary narrowing related to thickened intercoronary pillar (22%). After TAR, two patients (12%) had residual acute-angle takeoff and none had thickened intercoronary pillar. Reoperation occurred only in the TAR group in two patients (12%) for coronary stenosis. Neither group had residual slit-like ostium or intramural course. Notably, 97% of patients returned to exercise with a median follow-up of almost 5 years.

These data showed that, although repair of anomalous aortic origin of a coronary artery (AAOCA) has a high success rate, residual anatomical lesions remain. The findings of a separate study by the CHSS have shown that 5% of patients require coronary-related revision surgery 7 years following initial intervention.⁴ Although TAR abolished most of the high-risk features, there was a notable need for reintervention. This study identified specific high-risk residual lesions and its findings underscore the need for careful postoperative surveillance using computed tomographic angiography following the index AAOCA operation. Long-term clinical implications remain under study.

Improved Survival Rates With Less Ventricular Tachycardia After PVR in Patients With TOF

A study reported by Bokma et al. aimed to discern the impact of PVR on major adverse clinical outcomes in patients with repaired tetralogy of Fallot (rTOF).⁵ Using the INDICATOR (International Multicenter TOF Registry) data, the researchers examined whether PVR was linked to improved survival and reduced risk of sustained ventricular tachycardia (VT) in patients with rTOF. Among 1,143 patients with rTOF, the primary outcome (death or sustained VT) occurred in 82 (7%).

The data revealed that patients who underwent PVR had a 59% reduction in the risk of reaching the primary outcome compared with that of those who did not undergo PVR. Furthermore, this benefit was particularly evident in patients with advanced RV dilatation. Specifically, for patients with right ventricular end-systolic volume index (RVESVi) >80 mL/m², PVR significantly reduced the risk of the primary outcome. In contrast, no significant association was found between PVR and the primary outcome for those with RVESVi ≤80 mL/m².

The findings of this study, which was the largest international rTOF cohort, indicate that PVR is beneficial, especially for those with advanced RV dilatation. The findings emphasize the importance of PVR in reducing the risk of adverse outcomes such as death or sustained VT in patients with rTOF.

The findings of these studies are summarized in Table 1.

Table 1: Recent Study Data Showing Good Short-Term Outcomes for Self-Expanding TPVs

References

1. Gillespie MJ, McElhinney DB, Jones TK, et al. 1-year outcomes in a pooled cohort of Harmony transcatheter pulmonary valve clinical trial participants. JACC Cardiovasc Interv 2023;16:1917-28.
2. Argo MB, Barron DJ, Bondarenko I, et al. Hybrid palliation versus nonhybrid management for a multi-institutional cohort of infants with critical left heart obstruction. J Thorac Cardiovasc Surg 2023;166:1300-1313.e2.
3. Doan TT, Sachdeva S, Bonilla-Ramirez C, et al. Anomalous aortic origin of coronary arteries in children: postoperative high-risk anatomic features. Ann Thorac Surg 2023;115:991-8.
4. Jegatheeswaran A, Devlin PJ, Williams WG, et al. Outcomes after anomalous aortic origin of a coronary artery repair: a Congenital Heart Surgeons' Society study. J Thorac Cardiovasc Surg 2020;160:757-771.e5.
5. Bokma JP, Geva T, Sleeper LA, et al. Improved outcomes after pulmonary valve replacement in repaired tetralogy of Fallot. J Am Coll Cardiol 2023;81:2075-85.