Congenital Heart Surgery

Long-term surgical outcomes of congenital supravalvular aortic stenosis: a systematic review, meta-analysis and microsimulation study. Meccanici F, Notenboom ML, Meijssen J, Smit V, van de Woestijne PC, van den Bosch AE, Helbing WA, Bogers AJJC, Takkenberg JJM, Roos-Hesselink JW.Eur J Cardiothorac Surg. 2024 Jan 2;65(1):ezad360. doi: 10.1093/ejcts/ezad360.PMID: 37889257 Take Home Points The 30-year estimated survival rate after congenital SVAS repair was 91% compared to that of the matched general population The estimated 30-year reintervention rate (31%) and the risk of myocardial infarction (8%) were notably high. Commentary from Dr. Hironori Matsuhisa (Kobe, Japan), section editor of Congenital Heart Surgery Journal Watch: Summary This systematic review and meta-analysis included 23 publications reporting long-term outcomes following surgical repair for congenital supravalvular aortic stenosis (SVAS), encompassing a total of 1472 patients (median age at surgical repair: 5.8 years). The majority of the petients had the discrete type of SVAS (71.7%), and nearly half (49.6%) were diagnosed with Williams-Beuren syndrome. The repair techniques reported were single-patch repair (43.6%), pantaloons-shaped patch repair (33.2%), and three-patch repair (14.2%). The pooled early mortality rate following SVAS repair was 4.2% (95% CI: 3.2-5.5) and the late mortality was 0.61% (95%CI: 0.45 0.83) per patient-year. Additionally, the risk of sudden unexpected death was 0.36% (95% CI: 0.24 0.55) per patient-year. A microsimulation model over a 30-year time horizon estimated that life expectancy after SVAS repair was 90.7% (95%CI: 90.0-91.6) of the expected life expectancy of the matched general population.  Over the 30-year period, the estimated risk of myocardial infarction was 8.1% (95%CI: 7.3-9.9), and the reintervention rate was 31.3% (95%CI: 29.6–33.4), with 27.2% (95%CI: 25.8-29.1) of these reinterventions attributed to repair dysfunction (Figure). Comments Most studies on surgical outcomes for SVAS are based on small patient cohorts from single instisutions, with significant variations in patient characteristics and disease severity. This heterogeneity makes it challengint to develop a comprehensive understanding of long-term outcomes. The authors addressed this limitation by conducting a systematic review and meta-analysis and incorporated microsimulation models to predict 30-year survival and reoperation rates.  The relative life expectancy after SVAS repair was considerable. However, the risk of sudden unexpected death (0.36% per patient-year) and myocardial infarction (8% over 30 years) remain concerning. In general, patients requiring surgery before age of 1 year present with more severe disease and poorer prognoses. However, the findings emphasize the need for close, long-term follow-up for all patients to monitor the progression of coronary artery disease and biventricular outflow tract obstruction, both of which can lead to sudden death. Future research should identify factors that could enhance hybrid palliation outcomes, which would benefit centers with limited experience or volume, where adopting a primary Norwood strategy might be daunting. Additionally, as the authors mentioned, a study—possibly a randomized controlled study—to determine the factors in which hybrid palliation might yield better results than primary Norwood, could help improve outcomes of the treatment of HLHS in centers preferring primary Norwood, which still carries a considerable mortality risk.

Mortality and Heart Transplantation After Hybrid Palliation of Hypoplastic Left Heart Syndrome: A Systematic Review and Meta-Analysis. Jacquemyn X, Singh TP, Gossett JG, Averin K, Kutty S, Zühlke LJ, Abdullahi LH, Kulkarni A.World J Pediatr Congenit Heart Surg. 2024 Mar;15(2):215-223. doi: 10.1177/21501351231224323. Epub 2024 Feb 25.PMID: 38404131 Take Home Points This systematic review and meta-analysis found a high mortality rate in hybrid palliation of hypoplastic left heart syndrome patients, likely related to inclusion of those at highest risk. Mortality seems to be highest after initial palliation and decreases thereafter. Therefore, all patients should be closely followed during the initial interstage period to improve survival. Due to the persistent lack of substantial significant progress in hybrid palliation outcomes over an extended period, there remains a pressing need for additional research to address risk factors related to mortality following HP and to investigate alternative strategies for improving overall outcomes. Commentary from Dr. Chun Soo Park (Seoul, Korea), section editor of Congenital Heart Surgery Journal Watch:   Summary This study was designed to investigate the outcomes after hybrid palliation (HP) in hypoplastic left heart syndrome (HLHS) and its variants and to identify factors associated with death or transplantation. The authors systematically reviewed academic databases such as CINAHL, CINAHL PLUS, PubMed/MEDLINE, and SCOPUS to pick studies regarding the outcomes following HP in HLHS between 1998 and 2022. A total of 1162 patients from 33 publications were included in the analysis. Pooled incidence was estimated, and potential risk factors were identified using random-effects meta-analysis and reconstructed time-to-event data from Kaplan-Meier curves. Overall, 474 events (40.7%), including 417 deaths and 57 transplants, occurred. There was a trend toward decreasing mortality risk across the stages of palliation. Pooled mortality between HP and comprehensive stage 2 palliation was 25%, 16% between stage 2 and Fontan, and 6% after Fontan. The incidence of death or heart transplantation was higher in high-risk patients; 43% died and 10% received heart transplantation. Any risk factor associated with death or transplantation was not identified. Comments Despite the recent advancements in understanding of the disease and in treatments, including surgery, Hypoplastic Left Heart Syndrome (HLHS) remains a challenging congenital heart disease with a consistently high risk of mortality throughout the life. There is known to be significant attrition during the interstage period, which is between the Norwood operation, the first stage palliation, and the second-stage palliation, the bidirectional Glenn procedure. This attrition is further exaggerated in patients with high-risk anatomical or baseline characteristics. The hybrid palliation (HP) strategy was introduced to improve the survival outcome of HLHS, particularly by avoiding the cardiopulmonary bypass required for the first stage palliation, the Norwood operation, in the neonatal period. Even in centers that prefer primary Norwood, the hybrid strategy has been adopted for high-risk HLHS patients to drastically improve outcomes. The centers included in this study use HP for various purposes, making it challenging to simply evaluate its outcomes. However, the mortality or transplant rate following HP, and interstage mortality or transplant rates reaching over 25%, and the mortality or transplant exceeding 15% even after delayed performing more complex stage 2 procedures are somewhat disappointing in light of the strategy's original goals. Nevertheless, it is encouraging to see that the outcomes have been improving recently, likely due to accumulated experience with hybrid palliation and potentially unspecified modifications over time that have driven improvement. Future research should identify factors that could enhance hybrid palliation outcomes, which would benefit centers with limited experience or volume, where adopting a primary Norwood strategy might be daunting. Additionally, as the authors mentioned, a study—possibly a randomized controlled study—to determine the factors in which hybrid palliation might yield better results than primary Norwood, could help improve outcomes of the treatment of HLHS in centers preferring primary Norwood, which still carries a considerable mortality risk.