RESUMO
BACKGROUND: The purpose of our study was to assess the effects of a low dose of spironolactone in patients with moderate congestive heart failure (CHF) on the plasma level of brain natriuretic peptide (BNP), echocardiographic left ventricular ejection fraction (LVEF), and cardiopulmonary function assessed by cardiopulmonary (CP) test. MATERIAL/METHODS: 51 CHF patients (74.5% males, mean age 60 years) underwent transthoracic echocardiography, CP test, and plasma BNP assay at the time of enrollment and after 6 months of standard therapy for CHF plus a low dose of spironolactone (group A). A control group (21 patients, group B) was treated using standard therapy only. All subjects were in NYHA class I-III and had LVEF < or = 40%. RESULTS: BNP concentration decreased significantly (from 45.7+/-57.4 pg/ml to 18.6+/-26.9 pg/ml at follow-up; p=0.01), and the NYHA class and LVEF improved (2.2+/-0.6 vs 1.7+/-0.5, p=0.0001; 27.7+/-7.2% vs 35.1+/-11%, p=0.001 respectively) in subjects in group A. In spite of clinical amelioration, peak oxygen consumption, oxygen pulse and anaerobic threshold in the CP test did not change significantly (16.6+/-5.7 ml/kg/min vs 17.1+/-5.3 ml/kg/min p=0.5; 8.8 +/- 4.3 ml/beat vs 9.5+/-3.6 ml/beat p=0.2; 0.75+/-0.2 ml/Kg/min vs 0.73+/-0.2 ml/Kg/min p=0.7). No differences were noticed in the control group. CONCLUSIONS: The addition of spironolactone reduced the BNP plasma level in patients with moderate CHF and increased LVEF. This therapy improved the NYHA class without modifying the functional parameters in the CP test.
