Physiologic and Phenotypic Characteristics of Late Survivors of Tetralogy of Fallot Repair Who are Free from Pulmonary Valve Replacement
Background—Pulmonary valve replacement (PVR) after repair of tetralogy of Fallot (ToF) is commonly required and is burdensome. Detailed anatomic and physiologic characteristics of survivors free from late PVR and with good exercise capacity are not well described in a literature focusing on the indications for PVR.
Methods and Results—In 1085 consecutive patients receiving standard ToF repair in a single institution 1964-2009, survival and freedom from PVR were tracked. Of 152 total deaths, 100 occurred within the first postoperative year. Surviving patients between 10-50 years of age had an annual risk of death 4 (CL 2•8-5•4) times that of normal contemporaries. 189 patients have undergone secondary PVR to date, at mean age of 20±13 years (36% of those alive age 40). A random sample of 50 survivors (aged 4-57 years) free from PVR, underwent cardiovascular magnetic resonance, echocardiography and exercise testing. These patients had mildly dilated right ventricles (RVEDV=101±26 ml/m2) with good systolic function (RVEF=59±7%). Most had exercise capacity within normal range (z peak VO2=-0.91±1.3; z VE/VCO2 =0.20±1.5). In patients who are > 35 years with normal exercise capacity, there was mild residual RV outflow tract obstruction (mean gradient 24±13mmHg), pulmonary annulus diameters <+0.5z and unobstructed branch pulmonary arteries.
Conclusions—An important proportion of patients require PVR late after ToF repair. Patients surviving to age 35 without PVR and with a normal exercise capacity may have had a "definitive" primary repair; their RV outflow tracts are characterized by mild residual obstruction and pulmonary annulus diameter <0.5z.
- Received January 26, 2013.
- Revision received August 16, 2013.
- Accepted August 22, 2013.