Long-term combined therapy with losartan and an angiotensin-converting enzyme inhibitor improves functional capacity in patients with left ventricular dysfunction

OBJECTIVE: The efficacy of angiotensin-converting enzyme (ACE) inhibitors in the treatment of heart failure (HF) is well documented. However, ACE inhibitors may provide incomplete blockade of the renin-angiotensin-aldosterone system due to the alternative pathways for the production of angiotensin II (Ang II). The aim of this study was to evaluate the efficacy of combined therapy of an ACE inhibitor and the Ang II receptor blocker losartan in patients with HF by using cardiopulmonary exercise testing (CPET) on a treadmill. METHODS AND RESULTS: Seventeen patients (ejection fraction < or = 40%) were included in the study group. At the start of the study, all participants were on chronic ACE inhibitors therapy. Fifty mg losartan was added to the treatment and CPET was performed before and 6-8 months after starting losartan therapy. Sixteen patients with HF were included in the control group. CPET was performed once at the beginning and repeated 6-8 months later without any change in the treatment protocol. The change in CPET values (walk-time (WT), peakVO2, anaerobic threshold (AT), minute ventilation (VE), VE/VO2, peak heart rate (HR),VO2/HR) was investigated. In the losartan-treated group a significant increase was noted in WT (393 +/- 157 vs. 507 +/- 155 sec, p < 0.01); peak VO2 (1205 +/- 240 vs. 1330 +/- 253 ml/min, p < 0.05); and AT (794 +/- 131 vs. 895 +/- 177 ml/min, p < 0.05). In the control group exercise parameters did not change significantly. The change from baseline to follow-up between the two groups is statistically significant for WT and peak VO2 (114 +/- 94 vs. -58 +/- 134 sec, p < 0.0 1 and 125 +/-183 vs. -116 +/- 221 ml/min, p <0.01). CONCLUSIONS: Addition of losartan to the ACE inhibitor therapy in patients with HF improves functional capacity in the long run.