New oral contraceptives increase women’s cardiac risk

Women taking fourth-generation oral contraceptives, which use a progestin that is antiandrogenic, are at increased heart risk. The drugs significantly lengthen the corrected QT (QTc) by 3.6 milliseconds, according to a recent study in the Annals of Noninvasive Electrocardiology.

“Long QT is associated with risk of sudden cardiac death,” said Noel Bairey Merz, MD, FACC, FAHA, one of the study authors, to Formulary. Merz is director of the Barbra Streisand Women's Heart Center and professor of Medicine at 
Cedars-Sinai Heart Institute, in Los Angeles.

“While 3.6 milliseconds is not considered dangerous by itself, if [these drugs] are combined with other medications that lengthen the QT-azithromycin, antihistamines, and others-or certain health conditions, they could result in sudden cardiac death. More study is needed regarding the widespread use of fourth-generation oral contraceptives for non-contraceptive indications, such as acne.”

In a comprehensive ECG and pharmacy database review, researchers identified 410,782 ECGs performed at Northern California Kaiser Permanente on female patients between the ages of 15 and 53 years, from January 1995 to June 2008. QT was corrected for heart rate using log-linear regression.

Among the 410,782 women, 8.4% were taking oral contraceptives. In multivariate analysis after correction for comorbidities, there was an independent shortening effect of oral contraceptives. Users of first- and second-generation progestins had a significantly shorter QTc than nonusers (P<.0001).