Federal health experts say that new research is not strong enough to conclude that naproxen, the pain reliever in Aleve and many other medications, is safer on the heart than rival drugs used by millions of Americans to treat aches and pains. The Food and Drug Administration advisory panel voted 16-9 against the conclusion that naproxen has a lower risk of heart attack and stroke compared with similar anti-inflammatory medications like ibuprofen, sold as Advil and in other generic formulations. Debate about whether one drug in the class is safer than others has waged for more than a decade without a clear answer. The FDA convened the meeting this week to consider new analyses that apparently show lower heart risks for naproxen. But panelists said the data was not conclusive.