Tricuspid Valve and Right Ventricular Function Throughout the Hybrid Palliation Strategy for Hypoplastic Left Heart Syndrome and Variants

BACKGROUND Tricuspid valve (TV) and right ventricular (RV) function are major determinants of morbidity and mortality in patients with hypoplastic left heart syndrome (HLHS). We sought to retrospectively evaluate these parameters throughout the hybrid palliation strategy. METHODS From 2002 to 2018, 203 patients with HLHS and variants presented for hybrid stage I (HS1). Echocardiographic evaluation of tricuspid regurgitation (TR) and RV function was assessed at multiple time points. Clinical outcomes including tricuspid valvuloplasty, transplantation, and death were reviewed. RESULTS The most prevalent HLHS subtype was aortic atresia/mitral atresia. The presence of significant TR and/or RV dysfunction was 14.78% and 9.36%, respectively, at the time of initial HS1. There were 185 survivors following HS1 (91.13%, n = 185/203), while 147 patients underwent comprehensive stage II or bidirectional Glenn shunt (72.41%, n = 147/203). Tricuspid valvuloplasty was undertaken in nine patients (4.86%, n = 9/185). Ultimately, 100 patients underwent the Fontan procedure. The odds of development of significant TR and/or RV dysfunction were not statistically different throughout the stages of palliation (TR: odds ratio [OR] = 0.14-0.25, P = .5260; RV dysfunction: OR = 0.02-0.13, P = .3992). However, the risk of death and/or transplant was 2.5- to 3.8-fold when either were present alone or in combination (TR: OR = 2.58, P = .0356; RV dysfunction: OR = 3.84, P = .0262). Transplant-free survival at 15 years was 44.8%. CONCLUSION Following hybrid palliation for HLHS, the majority of survivors have normal RV and TV functions. Tricuspid valvuloplasty was required in few patients. Once significant TR and/or RV dysfunction ensues, there is a two- to three-fold risk of death and/or transplant.