As others have said, this study is comparing a very low salt diet to a recommended level of salt diet, and only in people who already have pre-existing cardiac

As others have said, this study is comparing a very low salt diet to a recommended level of salt diet, and only in people who already have pre-existing cardiac issues. Apparently the average American has a diet that has 1.5 times the recommended level, so what this study is looking at isn’t anything like that, let alone an even higher-salt diet. So you can’t take the study as saying anything about preventing heart disease generally. The one conclusion you perhaps could extrapolate from it is to say that the recommended limit is probably pretty good since it doesn’t seem to help going lower.