A DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY OF POSTMENOPAUSAL ESTROGEN REPLACEMENT THERAPY AND CAROTID-ARTERY PULSATILITY INDEX

Objective To determine whether postmenopausal oestrogen replacement th erapy affects carotid artery pulsatility index. Design A prospective d ouble-blind placebo controlled trial. Setting University associated te aching hospital. Participants Twenty-eight postmenopausal women who we re more than 12 months postmenopausal and who had not taken exogenous oestrogen. Interventions Independent randomisation to receive oral oes tradiol (2 mg daily) or placebo for 20 to 24 weeks. Main outcome measu res Internal carotid artery Doppler pulsatility index, measured within one centimetre of the carotid bifurcation. Results Replicate data wer e available from 27 women. The mean pulsatility index decreased by -0. 11 in 15 women receiving oestradiol, compared with a mean rise of 0.05 in the 12 women who received placebo (P = 0.006, 95% CI for treatment difference 0.06-0.31). Conclusions Oestrogen replacement decreases po stmenopausal carotid artery pulsatility index, probably reflecting dec reased peripheral vascular resistance. This is a further mechanism whe reby hormone replacement therapy may impart cardiovascular protection.