BackgroundFor patients with hypoplastic left heart syndrome, digoxin has been associated with reduced interstage mortality after the Norwood operation, but the mechanism of this benefit remains unclear. Preservation of right ventricular (RV) echocardiographic indices has been associated with better outcomes in hypoplastic left heart syndrome. Therefore, we sought to determine whether digoxin use is associated with preservation of the RV indices in the interstage period.Methods and ResultsWe conducted a retrospective cohort study of prospectively collected data using the public use data set from the Pediatric Heart Network Single Ventricle Reconstruction trial, conducted in 15 North American centers between 2005 and 2008. We included all patients who survived the interstage period and had echocardiographic data post‐Norwood and pre‐Glenn operations. We used multivariable linear regression to compare changes in RV parameters, adjusting for relevant covariates. Of 289 patients, 94 received digoxin at discharge post‐Norwood. There were no significant differences in baseline clinical characteristics or post‐Norwood echocardiographic RV indices (RV end‐diastolic volume indexed, RV end‐systolic volume indexed, ejection fraction) in the digoxin versus no‐digoxin groups. At the end of the interstage period and after adjustment for relevant covariates, patients on digoxin had better preserved RV indices compared with those not on digoxin for the ΔRV end‐diastolic volume (11 versus 15 mL, P=0.026) and the ΔRV end‐systolic volume (6 versus 9 mL, P=0.009) with the indexed ΔRV end‐systolic volume (11 versus 20 mL/BSA^1.3, P=0.034). The change in the RV ejection fraction during the interstage period between the 2 groups did not meet statistical significance (−2 versus −5, P=0.056); however, the trend continued to be favorable for the digoxin group.ConclusionsDigoxin use during the interstage period is associated with better preservation of the RV volume and tricuspid valve measurements leading to less adverse remodeling of the single ventricle. These findings suggest a possible mechanism of action explaining digoxin’s survival benefit during the interstage period.

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地高辛与保留期间期超声心动图指数的关联：解释提高生存率的可能机制？

背景对于左心发育不良综合征患者，地高辛与 Norwood 手术后的阶段间死亡率降低有关，但这种益处的机制仍不清楚。保留右心室 (RV) 超声心动图指标与左心发育不良综合征的更好结果相关。因此，我们试图确定地高辛的使用是否与阶段间期 RV 指数的保留有关。方法和结果我们使用来自儿科心脏网络单心室重建试验的公共使用数据集对前瞻性收集的数据进行了回顾性队列研究， 2005 年至 2008 年间在 15 个北美中心进行了研究。我们纳入了在诺伍德手术后和格伦手术前存活并具有超声心动图数据的所有患者。我们使用多变量线性回归来比较 RV 参数的变化，调整相关协变量。在 289 名患者中，94 名在 Norwood 后出院时接受了地高辛。地高辛组与非地高辛组的基线临床特征或诺伍德超声心动图后右室指数（右室舒张末期容积指数、右室收缩末期容积指数、射血分数）无显着差异。在期间期末期和相关协变量调整后，与未使用地高辛的患者相比，使用地高辛的患者在 ΔRV 舒张末期体积（11 对 15 mL，地高辛组与非地高辛组的基线临床特征或诺伍德超声心动图后右室指数（右室舒张末期容积指数、右室收缩末期容积指数、射血分数）无显着差异。在期间期末期和相关协变量调整后，与未使用地高辛的患者相比，使用地高辛的患者在 ΔRV 舒张末期体积（11 对 15 mL，地高辛组与非地高辛组的基线临床特征或诺伍德超声心动图后右室指数（右室舒张末期容积指数、右室收缩末期容积指数、射血分数）无显着差异。在期间期末期和相关协变量调整后，与未使用地高辛的患者相比，使用地高辛的患者在 ΔRV 舒张末期体积（11 对 15 mL，P = 0.026）和 ΔRV 收缩末期容积（6 对 9 mL，P = 0.009）和指数 ΔRV 收缩末期容积（11 对 20 mL/BSA ^1.3，P = 0.034）。两组间期间期 RV 射血分数的变化不符合统计学意义（-2 对 -5，P = 0.056）；然而，地高辛组的趋势仍然是有利的。结论在间期使用地高辛与更好地保存右室容积和三尖瓣测量值相关，从而减少单心室的不良重塑。这些发现表明了一种可能的作用机制，可以解释地高辛在期间期的生存益处。