Investigations of the peripheral vascular mechanisms implicated in congestive heart failure by the non-invasive evaluation of radial artery compliance and reactivity

Abstract

The viscoelastic, muscular and endothelial components of the vessel wall may be altered in patients with congestive heart failure (CHF). In order to investigate the relative contribution of each of these components to the peripheral vascular mechanisms of the disease, we have studied post-ischemic (endothelial-dependent) and post-nitroglycerin (endothelial-independent) vasodilatation as well as the response to cold pressure test and the geometry and compliance of the radial artery using a non-invasive echotracking method coupled to digital photoplethysmography. Thirty-nine patients with congestive heart failure (ejection fraction = 28 +/- 2%) were compared to age- and sex-matched healthy controls. Baseline therapy was unchanged during the study. In congestive heart failure patients, cross-sectional compliance and volumic distensibility were greater (P < 0.05) but isobaric compliance which is independent of blood pressure value was unchanged. Post-ischemic and post-nitroglycerin vasodilatation were lower (7 +/- 1 vs. 11 +/- 1%, P < 0.01 and 6 +/- 1 vs. 14 +/- 2%, P < 0.001, respectively) and both of the arterial diameter and pressure responses to cold pressor test were blunted (-5 +/- 1 vs. -8 +/- 1%, P = 0.058 and 6 +/- 3 mmHg vs. 13 +/- 2 mmHg, P < 0.01, respectively) in congestive heart failure. These changes were similar in primary and ischemic congestive heart failure, suggesting that they are more likely related to common neuro-hormonal factors rather than to an atherosclerotic process.