I wouldn't worry too much about this type pf news. Even if it does increase your chance its your specific chance not an over all 30% chance it will happen. Just look at cancer, it seems every week a study comes out telling you x,y and z increases your chances of getting cancer, if it was an over all chance we would all have cancer more than once in our life.In order to have a heart attack you would need more than just a suppliment and your doctor will most likely be checking your stats when you see him, smoking cigarettes will do a lot more than calcium would and the study itself says it is unlikely to be the calcium itself but the lack of vitamin D to regulate it. Don't smoke, eat healthy, exercise and you will outlive me and I am in my 20's.