A study called ENHANCE has revealed that people taking the cholesterol-lowering drug Vytorin, a combo of the statins Zetia (ezetimibe) and Zocor (simvistatin), didn’t end up with a lower risk of heart attack than those on Zocor alone. (In Vytorin, Zetia cuts cholesterol in the intestines, Zocor in the liver.) Vytorin did lower LDL (“bad” cholesterol) more than solo Zocor. But that didn’t shrink the amount of plaque in arteries, which is linked to heart attacks.

Daniel Lee, MD, who treats heart disease in people with HIV at the University of California San Diego, advises people to continue taking their cholesterol meds. Lee calls ENHANCE’s results inconclusive, adding that Zetia’s benefits for those with high LDL have been proven. (Many positive people battle high cholesterol; due to HIV-med interactions, most pair Zetia with statins other than Zocor.) “Lowering LDL is still the main thing,” Lee says. A heart-healthy diet has been shown to help lower LDL, so he also prescribes a visit to a dietician.