Clinical research Spironolactone improves lung diffusion in chronic heart failure

Aims To evaluate whether anti-aldosteronic treatment influences lung diffusion (DLCO) in chronic heart failure (HF) patients. Spironolactone improves clinical conditions and prognosis in chronic HF and reduces connective tissue matrix turnover; DLCO abnormalities in chronic HF are related to increase in fibrosis and connective tissue derangement. Methods and results Thirty stable chronic HF patients, with reduced DLCO (,80 % of predicted), were randomly assigned to active treatment (25 mg spironolactone daily) or placebo in addition to conventional anti-failure treatment. They were eval-uated by quality of life questionnaire, laboratory investigations, cardiopulmonary exercise test, and pulmonary function test, which included DLCO and membrane diffusing capacity (DM). The evaluation was done before treatment and 6 months after. Quality of life score and standard pulmonary function tests were not signifi-cantly affected by spironolactone, while active treatment increased DLCO due to an increase of DM (DLCO: 18.3+ 3.9 vs. 19.9+ 5.5 mL/min/mmHg; DM: 28.1+ 7.7 vs. 33.3+ 8.6 mL/min/mmHg) and peak oxygen consumption (peak VO2 16.8+ 1.9 vs.18.6+ 2.2 mL/min/kg). Increments of DLCO and peak VO2 were linearly related (R 0.849, P, 0.001). Conclusion These data show a positive effect of spironolactone on gas diffusion and exercise capacity suggesting a novel mechanism by which anti-aldosteronic drugs improve HF clinical condition and prognosis