Abstract 13082: Ventricular Hyper-Fibrogenesis Assessed by Serum Levels of Amino-Terminal Propeptide of Type III Procollagen During Staged Fontan Procedure
Background: Preserving ventricular function before and after Fontan procedure is a key element in establishing successful Fontan circulation. We tested the hypotheses that 1) volume overload and/or cyanosis generally observed in the single ventricle (SV) circulation before Fontan surgery is associated with ventricular hyper-fibrogenesis and 2) Fontan procedure effectively ameliorates ventricular fibrogenesis, but sustained hyper-fibrogenesis in the Fontan ventricle is associated with ventricular diastolic dysfunction.
Methods: Serum levels of amino-terminal propeptide of type III procollagen (PIIIP), a marker of fibrogenesis, were measured in 63 patients with a single ventricle (SV) and in 111 healthy children (control). The children with SV were divided into three groups according to clinically relevant stage: (1) Unoperated children or children who underwent first-stage repair (Blalock-Taussig shunt or pulmonary artery banding: BTS/PAB group, n=63). (2) Children who underwent second-stage palliation (Glenn group, n=59). (3) Children who underwent Fontan surgery (Fontan group, n=36).
Results: The PIIIP levels decreased significantly after the Glenn shunt procedure, and further decreased after the Fontan procedure, although the level was still significantly higher than that of the control (BTS/PAB group: 5.3±2.1, Glenn group: 1.8±1.0, Fontan group: 1.5±0.5, Control: 1.1±0.3 U/ml). Increased ventricular volume load assessed by pulmonary to systemic flow ratio (Qp/Qs) was significantly associated with increased PIIIP levels in children with BTS/PAB (r=0.674, p<0.01), while PIIIP levels in the Glenn group correlated significantly with the severity of cyanosis (r=0.459, p<0.01). In the Fontan group, high PIIIP levels correlated significantly with increased ventricular diastolic stiffness assessed by end-diastolic pressure-area relationship (r=0.44, p<0.05).
Conclusions: Our results suggest ventricular hyper-fibrogenesis in patients with SV circulation. Staged-Fontan procedure can ameliorate this process, but therapies that can further suppress fibrogenesis may be more effective in improving the prognosis after the Fontan procedure.
- © 2011 by American Heart Association, Inc.