Angiotensin-converting enzyme inhibitor therapy improves respiratory muscle strength in patients with heart failure

Study objectives: Respiratory muscle strength has been shown to be reduced in patients with chronic heart failure. The purpose of this prospective study was to determine whether long-term therapy with the angiotensin-converting enzyme (ACE) inhibitor perindopril improves respiratory muscle strength in patients with chronic heart failure. Patients and methods: Eighteen patients with stable chronic heart failure were administered perindopril, 4 mg/d, in addition to their standard therapy for a period of 6 months, Fourteen patients completed the study. Maximum inspiratory pressure (PImax) and maximum expiratory pressure (PEmax) expressed in percentage of predicted values, left ventricular ejection fraction (LVEF) determined by means of two-dimensional echocardiography, and pulmonary volumes were obtained before and after therapy. Measurements and results: As compared to baseline, there was a significant increase in both PImax and PEmax after therapy (57 +/- 27% predicted vs 78 +/- 36% predicted and 62 +/- 20% predicted vs 73 +/- 15% predicted, respectively; each p < 0.05), LVEF increased (34 +/- 5% vs 41 +/- 10%; p < 0.05); functional class improved by greater than or equal to 1 New York Heart Association (NYHA) class in five patients. There were no changes in pulmonary volumes, No correlation was found between changes in PImax and PEmax and changes in either LVEF or NYHA functional class. Conclusions: In patients with chronic heart failure, long-term therapy with the ACE inhibitor perindopril improved respiratory muscle strength, as indicated by significant increases in PImax and PEmax.