Thirty-three patients with CHF were evaluated: six-minute walk test, NYHA class, brain natriuretic peptide (BNP), big Endothelin-1 (bigET-1) and flow-mediated vasodilation (FMD) of the brachial artery were assessed at baseline and after a 3-month period of optimized neurohormonal therapy. Two groups were formed retrospectively based on the changes in submaximal exercise capacity (responders and non-responders).
Optimization of neurohormonal therapy was comparable between groups. Responders (n = 17) revealed a significant increase in walking distance (304 ± 109 to 441 ± 75 m; p < 0.01), which was paralleled by a decrease in NYHA class (2.7 ± 0.6 to 2.0 ± 0.4; p < 0.01), BNP (484 ± 454 to 243 ± 197 pg/ml; p < 0.01), and bigET-1 (2.0 ± 0.9 vs. 1.5 ± 0.6 fmol/ml; p = 0.04). By contrast, the latter variables did not change in non-responders. Improvement in functional capacity in responders was associated with an increase in FMD (8.2 ± 3.9 % to 11.0 ± 5.6 % ; p < 0.05). Increments in FMD were directly correlated with increases in walking distance (r = 0.34; p < 0.05).
Short-term improvement of submaximal exercise capacity in CHF patients following optimized therapy with ACE inhibitors and beta blockers is associated with restoration of endothelial function in conduit arteries.