What you really need is a study comparing saturated fats, ideally from butter AND from coconut oil, with monounsaturated fat which is the plant fat recommended as healthiest (olive oil, avocados, almonds), not polyunsaturates that no-one claimed was particularly healthy to begin with. It also needs to looks at all cardiac events, not just death (having cardiac events can reduce life quality).

If you read the wiki about saturated fats https://en.wikipedia.org/wiki/Saturated_fat_and_cardiovascul... it's clear that there's no benefit from saturated fats, but potential downfalls.

A more useful headline: "Replacing butter with vegetable oils high in monounsaturated fatty acid reduces risk of cardiac events and neurological disorders" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705810

So much butter confirmation bias here.