Which combined OC to prescribe with CV safety in mind?
With various formulations available, which combined OC should you recommend to minimize not only the risk of PE, but also the risk of stroke and MI?
PRACTICE CHANGER
When prescribing combined oral contraceptives, choose one containing levonorgestrel and low-dose estrogen (20 mcg) to minimize the risks of pulmonary embolism, ischemic stroke, and myocardial infarction.
STRENGTH OF RECOMMENDATION
B: Based on a good quality, patient-oriented cohort study.
Weill A, Dalichampt M, Raguideau F, et al. Low dose oestrogen combined oral contraception and risk of pulmonary embolism, stroke, and myocardial infarction in five million French women: cohort study. BMJ. 2016;353:i2002.1
CAVEATS
A cohort study, no contraceptive start date, and incomplete tobacco use data
This is an observational cohort study, so it is subject to confounding factors and biases. It does, however, include a very large population, which improves validity. The study did not account for COC start date, which may be confounding because the risk of VTE is highest in the first 3 months to one year of COC use.
CHALLENGES TO IMPLEMENTATION
Low-dose estrogen is associated with increased vaginal spotting
One potential challenge to implementing this practice changer may be the increased rate of vaginal spotting associated with low-dose estrogen. COCs containing 20 mcg of estrogen are associated with spotting in approximately two-thirds of menstrual cycles over the course of a year.14 That said, women may prefer to endure the spotting in light of the improved safety profile of a lower-dose estrogen pill.
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center For Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.
