794-2 Angiotensin Converting Enzyme Inhibition in Adults with Cyanotic Congenital Heart Disease

Adult patients (pts) with cyanotic congenital heart disease (CCHD) and elevation (↑) in pulmonary vascular resistance (PVR) may have a marked decrease in exercise capacity (EX) and quality of life due to intravascular volume overload, ventricular dysfunction and cyanosis-related morbidity. Concerns of increasing right-to-left shunting and cyanosis have limited characterization of the safety and effects of angiotensin converting enzyme inhibition (ACEI) in these pts. We evaluated ACEI in 7 symptomatic adults (ages 29–36 yrs) with CCHD and ↑PVR from 6/92 to 6/94. Intracardiac shunting was present at the ventricular level (single ventricle, double outlet right ventricle) in 3 pts, at the atrial septum (Ebstein's malformation, peripheral pulmonary stenoses) in 2 pts, and at both levels (AV canal defect) in 2 pts. All pts had marked exercise incapacity; 6/7 were candidates for heart-lung transplantation. Baseline serum hemoglobin (Hgb) oxygen saturation (O2sat) and 6 minute walking capacity (6 min) were compared before and after 6 weeks of ACEI. Baseline Hgb was ≥6 gm/dl (19.3 ± 1.7) and O2sat was ≤90% (79 ± 4) in all pts. ACEI caused no decrease in O2sat or increase in Hgb in any pt. When compared to baseline, EX increased ≥30% (6 min: 326 ± 129 vs 441 ± 160 yds) with ACEI in 5/5 pts (p = 0.01). All pts noted subjective functional improvement with ACEI; during treatment 3/6 pts removed themselves from consideration for organ transplantation and remain well. Our preliminary findings suggest that short-term ACEI is safe and may improve exercise capacity and quality of life in adult pts with CCHD and ↑PVR . Further investigation is required to elucidate the mechanisms of these benefits and to determine the long-term effects of ACEI in this cohort.