Is HT Safe in Statin Users?
Berglind IA, Andersen M, Citarella A, Liet al. Hormone therapy and risk of cardiovascular outcomes and mortality in women treated with statins. Menopause. 2015;22(4):369–376. Hodis HN, Mack WJ. Hormone therapy and risk of all-cause mortality in women treated with statins [comment]. Menopause. 2015;22(4):363–364.
Since the initial publication of findings from the WHI, clinicians have been cautioned not to prescribe menopausal HT in women at elevated risk for CVD. In this study from Sweden, investigators enrolled women ages 40 to 74 who initiated statin use between 2006 and 2007 due to known CVD (secondary prevention) or in the absence of known CVD (primary prevention). Women were followed for a mean of four years after beginning statins, until the end of 2011.
Of 40,958 statin users, 7% used HT (mean age of HT users and nonusers was 61 and 62, respectively). Overall, 70% of statin use was for primary prevention. Deaths from CVD occurred in 5 and 18 patients per 10,000 person-years among HT users and nonusers, respectively (HR, 0.38). All-cause mortality occurred in 33 and 87 patients per 10,000 person-years among HT users and nonusers, respectively (HR, 0.53). These reduced risks for mortality noted in women who used concomitant statins achieved statistical significance. Whether statins were used for primary or secondary prevention, the incidence of cardiovascular events was similar in HT users and nonusers.
Why these findings diverge from those of the WHI
The findings of this large prospective cohort study are consistent with findings from other large observational studies—though they diverge from WHI findings. As Berglind and colleagues note, few WHI participants used statins at baseline. Also in contrast with the WHI, in which all HT was based on conjugated estrogen, all HT users in this Swedish study used oral or transdermal estradiol, as conjugated estrogen is not available in Sweden (and appears to be associated with an elevated risk for CVD, compared with other estrogens1).
REFERENCE
1. Smith NL, Blondon M, Wiggins KL, et al. Lower risk of cardiovascular events in postmenopausal women taking oral estradiol compared with oral conjugated equine estrogens. JAMA Intern Med. 2014;174(1):25–31.