Cardiovascular risks associated with the use of drospirenone-containing combined oral contraceptives.

OBJECTIVES

The "Long-term Active Surveillance Study for Oral Contraceptives" investigated the risks of long-term use of a 21-day regimen of drospirenone and ethinylestradiol (DRSP) compared to established oral contraceptives (OCs) in a routine clinical setting.

STUDY

DESIGN

Prospective, controlled, non-interventional cohort study conducted in seven European countries with three main exposure groups: new users of DRSP, levonorgestrel-containing OCs (LNG), and OCs containing other progestogens (Other OCs). All self-reported clinical outcomes of interest (OoI) were validated via attending physicians and relevant source documents. Main OoI were serious clinical outcomes, in particular cardiovascular events. Comprehensive follow-up procedures were implemented. Statistical analyses were based on Cox regression models.

RESULTS

A total of 1,113 study centers enrolled 59,510 women. Overall 28%, 26% and 45% of these women used DRSP, LNG and Other OCs, respectively. Study participants were followed for up to ten years (mean value, 5.4years), which generated 318,784 woman-years (WY) of observation. Low loss to follow-up and drop-out rates of 2.9% and 16.8% were achieved. DRSP, LNG, and Other OCs showed similar incidence rates of venous thromboembolism. Corresponding hazard ratios (HRs) were close to unity. For arterial thromboembolic events (ATE) and initiation of antihypertensive treatment statistically significant lower risks were found for DRSP compared to LNG and Other OCs.

CONCLUSION

DRSP use was associated with similar general health risks and a low risk of ATE compared to OCs containing other progestogens.

IMPLICATION STATEMENT: The 21-day regimen of drospirenone-containing combined oral contraceptives is associated with similar risk of VTE compared to other combined oral contraceptives as well as potentially with a lower risk of ATE.