[Use of enalapril, an angiotensin-converting enzyme inhibitor, in pulmonary artery hypertension].

Enalapril (E) was used to treat 16 patients with pulmonary arterial hypertension, 6 primary and 10 secondary, 5 of the latter with congenital heart disease and 5 with chronic obstructive pulmonary disease. The average dose of E was 20 mg/day. All patients underwent pre and post-treatment cardiac catheterization with determination of pressures at: right atrial (RA), main pulmonary artery (MPA), pulmonary capillary wedge pressure ( VCP) and systemic arterial (SA). Resistances forces were also measured as; total pulmonary (TPR), pulmonary arteriolar (PAR) and total systemic (TSR) as well as cardiac output (CO), and echo and electrocardiograms, chest x ray, stress test and respiratory function test. The functional class (NYHA) improved in all (p less than 0.001). The initial mean pressures were: RA 12.24 +/- 4.35; MPA 73.81 +/- 25.16; VCP 12 +/- 2.73 and SA 89 +/- 14; TPR 1477 +/- 761; PAR 1243 +/- 730 and TSR 1684 +/- 505.5; CO 4.5 +/- 1.29. The final values were: RA 9.66 +/- 2.46 (p less than 0.001); MPA 63.26 +/- 24.45 (p less than 0.001); VCP 11.33 +/- 2.38 (p = NS); SA 81 +/- 10 (p less than 0.001); TPR 1009.5 +/- 536.7 (p less than 0.001); PAR 829 +/- 511.5 (p less than 0.001); TSR 1309.6 +/- 296.3 (p less than 0.001); CO 5.2 +/- 1.44 (p less than 0.001). The average of minutes on treadmill was initially 8.2 +/- 2.45 and final 12.46 +/- 3.0 (p less than 0.001). It is concluded that enalapril is a useful drug in the treatment of pulmonary arterial hypertension of any etiology.