[Peripheral vasodilators: from the hemodynamic effect to clinical benefit]

Patients with chronic occlusive arterial disease of lower limbs have an excess mortality due to associated cardiovascular diseases or cancer. They also have an important morbidity with a high prevalence of coronary artery diseases and strokes. In this context, the only benefit of peripheral vasodilators devoid of any effect on morbidity and mortality, could be only on quality of life. Haemodynamic effects of these drugs have been evaluated by several reproducible techniques in order to measure the peripheral blood flow (plethysmography, 133Xe clearance, transcutaneous oxygen-pressure, electromagnetic debimetry). An increase in blood flow has been demonstrated in patients receiving pentoxifylline, naftidrofuryl, or blufomedil in phase II clinical trials using these different methods. No general haemodynamic effect has been observed with these drugs which were better denominated vaso-active drugs. However the most relevant criteria remained to confirm a clinical benefit, particularly on intermittent claudication. Number of positive clinical trials in patients with intermittent claudication have been published, but from a methodological point of view few of them were suitable and demonstrated a statistically significant benefit. Criticisms were mainly related to the type of trial (cross-over is not recommended because of the drug-period effect), the lack of 'intention to treat' analysis, the inhomogeneity of the compared groups (for example different percentages of diabetics and excess of drop-outs). In spite of an established haemodynamic effect and of a demonstrated benefit in claudicants, peripheral vasodilators appear to have a slight interest in the global care of patients with occlusive arterial disease of lower limbs mainly on functional symptoms.