Effects, of intravenous prostaglandin E1 on arterial compliance:: a randomized controlled trial

Background: Prostanoids are in widespread use for the treatment of critical limb ischemia and are suggested to improve arterial compliance. However, dose- and time-dependency of these drug effects are indeterminate. We investigated the influence of intravenous application of prostanoids on arterial compliance parameters in patients with critical limb ischemia due to peripheral artery disease (PAD). Patients and methods: We included 82 consecutive patients with PAD Fontaine stage III and IV in a patient-blinded, randomized controlled trial. Patients were randomly assigned to either single dose intravenous treatment with 40 mug (n = 29) or 60 mug (n = 27) of Alprostadil (PGE) in 2.50 ml 0.9% saline over 2 hours, or 250 nil 0.9% saline solution as a placebo group (n = 26). Large and small artery compliance was measured by peripheral pulse contour analysis at base line, at one hour during intravenous infusion of Alprostadil, immediately after and 24 hours after the end of the infusion. For study purpose the patients received Alprostadil only once during the observation period of 2 days. Results: Large artery compliance, blood pressure, heart rate and cardiac output were unaffected by PGE administration irrespectively of drug-dosage or time interval. Small artery compliance increased at I hour during intravenous application of Alprostadil (40 mug Alprostadil p = 0.001; 60 mug Alprostadil p < 0.0001) compared to placebo and increased median +47% (IQR +5% to +100%) after administration of 40 mug Alprostadil and median +32% (IQR -11% to +88%) after 60 mug Alprostadil (p = 0.5). Immediately after the end of Alprostadil infusion small artery compliance decreased to baseline levels. Conclusions: Prostaglandin E-1 causes a significant improvement of small artery compliance during the time of intravenous application. However this effect rapidly diminishes after the end of administration and no dose-dependency between 40 mug and 60 mug Alprostadil is observed.