Background: flow-mediated arterial dilation (FMAD), an indicator of endothelial function, is reduced in patients with heart failure and reduced left ventricular ejection fraction (HFREF). Many elderly patients with heart failure exhibit a normal left ventricular ejection fraction (HFNEF). It is unknown whether FMAD is severely reduced in the elderly with HFNEF.
Methods and results: 30 participants >60 yr of age, 11 healthy, 9 with HFNEF, and 10 with HFREF, underwent a cardiovascular magnetic resonance (CMR) assessment of FMAD in the superficial femoral artery followed within 48 h by symptom-limited exercise with expired gas analysis. Elderly patients with HFREF and HFNEF had severely reduced peak oxygen consumption (Vo(2 peak); 12 +/- 2 and 13 +/- 1 ml.kg(-1).min(-1), respectively) vs. their healthy age-matched contemporaries (20 +/- 3 ml.kg(-1).min(-1)). FMAD was 3.8 +/- 1.3% (0.85 +/- 0.22 mm(2)) in patients with HFREF; it was 12.1 +/- 3.6% (3.1 +/- 1.2 mm(2)) and 13.7 +/- 5.9% (3.9 +/- 1.7 mm(2)), respectively, in patients with HFNEF and age-matched healthy older individuals. After adjustment for age and gender, the association of FMAD with Vo(2) was high in healthy and HFREF subjects (P = 0.05 and 0.02, respectively) but less so in HFNEF participants (P = 0.58).
Conclusions: elderly patients with HFNEF do not exhibit marked reduction in leg FMAD. These data suggest that mechanisms other than impaired femoral arterial endothelial function contribute to the severe exercise intolerance experienced by these individuals.