Raloxifene reduces impedance to flow within the uterine artery in early postmenopausal women: A 2-year randomized, placebo-controlled, comparative study

Objective: We sought to investigate the long-term effect of raloxifene and continuous combined hormone replacement therapy (ccHRT) on impedance to flow within the uterine artery in postmenopausal women. Study Design: A prospective, randomized, double-blind, placebo-controlled 2-year study was performed in 95 postmenopausal women. They received either 60 mg of raloxifene daily (raloxifene 60 group), 150 mg of raloxifene daily (raloxifene 150 group), ccHRT, or placebo. At baseline and thereafter every 6 months, color Doppler ultrasonography was used to measure the pulsatility index (PI) of the uterine artery. Results: After 24 months of treatment, compared with placebo, significant decreases were found in the PI in the raloxifene 150 group (P = .021) and in the ccHRT group (P = .007). In the raloxifene 150 group compared with the placebo group, after 6 and 24 months, decreases were observed in median PI of –5% and –15%, respectively, and in the ccHRT group decreases of –2% and –19%, respectively, were found. Conclusion: Long-term use of 150 mg of raloxifene daily or ccHRT reduces impedance to flow within the uterine artery. This indicates that high-dose raloxifene may exert cardiovascular protection. (Am J Obstet Gynecol 2001;185:557-62.)