Abstract 3122: ACE Inhibition Improves Systolic LV Function in Patients with Pulmonary Regurgitation and Restrictive RV Physiology Late After Repair of Tetralogy of Fallot - A Subgroup Analysis of the APPROPRIATE Study (ACE Inhibitors for Potential PRevention Of the deleterious effects of Pulmonary Regurgitation In Adults with TEtralogy of Fallot Repair)
Background: Precise effects of Angiotensin Converting Enzyme (ACE) inhibition in adults with repaired tetralogy of Fallot (rTOF) and pulmonary regurgitation (PR) are unknown. Though restrictive right ventricular (RV) physiology may confer protection against the deleterious effects of PR initially, this effect may not last.
Methods and Results: Sixty-Four stable patients with rTOF and at least moderate PR completed 6 months ramipril 10 mg (n=32) or placebo (n=32) once daily in a randomised, double-blinded, placebo-controlled trial (ISRCTN 97515585). All participants had cardiovascular magnetic resonance, cardiopulmonary exercise testing, neurohormones and 12-lead electrocardiogram at baseline and follow-up. Twenty-seven had restrictive RV physiology (mean age 32.8 ± 10.1 years;11 ramipril,16 placebo) on Doppler-echocardiography. In subgroup analyses of these patients there was a significant decrease in left ventricular (LV) end systolic volume index (ESVi) and increase in LV ejection fraction (EF) in those assigned ramipril compared with placebo (difference between baseline and follow-up changes for ramipril versus placebo: −2.4 ± 4.9 versus 2.7 ± 3.6ml/m2;P=0.005, 2.5 ± 5.0 versus −1.25 ± 3.5%;P=0.03; Figure⇓). These changes were not however associated with improvement in objective exercise capacity, RV function, PR, or neurohormones.
Conclusions: In adults with rTOF, PR and restrictive RV physiology, ramipril therapy led to increased LVEF and decreased LVESVi. Benefits of ACE inhibitors with regards LV function are well described but previously unreported in this population. The potential prognostic effect of these observations merits further study.