The findings could have further significance for those women taking low-dose oral contraceptives who already are at increased risk for such events because of polycystic ovary syndrome, or metabolic disorder, according to John Nestler, M.D., professor and chair of the Division of Endocrinology and Metabolism in the VCU School of Medicine.

In the study, researchers reported that the overall estimated risk of cardiovascular events - both heart attack and stroke -- among current low-dose oral contraceptive users was doubled compared to non-users.

"Prolonged exposure to low-dose oral contraceptives in a population at higher risk may significantly increase the incidence of cardiovascular outcomes and prompt consideration of alternative therapeutic or contraceptive interventions," he wrote.

"A number of women with metabolic syndrome or polycystic ovary syndrome already are at increased risk for heart attack, and a majority of women with PCOS are treated with low-dose oral contraceptives for a prolonged period of time," he said. "An insulin-sensitizing drug might confer better general health benefits than the oral contraceptive."

"For example, insulin-sensitizing drugs have been shown to decrease progression to Type 2 diabetes, and there is evidence suggesting that they also may lower the risk of cardiovascular disease and have beneficial effects on cardiovascular risk factors," he said.

"Despite the doubling of risk associated with the pill, the absolute risk for a cardiovascular event in an individual woman taking the pill is low - Women using the pill are not going to automatically have a heart attack," said Nestler. "However, our findings do raise the issue of whether oral contraceptives are optimal therapy for certain groups of women who are at baseline risk or who are taking the pill for a longer time, such as women with PCOS."