“It turns out there's a right and wrong place for the plumbing analogy. It's right for people who have heart attacks that involve a sudden, total blockage of a coronary artery. That's why procedures to unclog arteries with expandable stents and balloons ("angioplasty") save lives in emergencies and need to be used more in that setting. But the plumbing analogy fails when applied to stable, partial blockages that don't lead to sudden heart attacks. And yet doctors can't let go of the plumbing talk, and they keep unclogging partial blockages. That's why the vast majority of angioplasties are done for the wrong reasons—that is, for prevention, not acute treatment.”
Ironically, Sanghavi quotes one of his sources invoking a metaphor to explain why preventative angioplasties don’t work: “The trigger isn't bad plumbing—but something more akin to a land mine. People at risk of heart attacks have largely invisible cholesterol plaques throughout their arteries, which act, he says, like unpredictable "little bombs that blow up suddenly and cause a sudden and devastating blockage" in previously healthy-appearing areas.”
More proof, if it were needed, that both lay people and professional decision makers use metaphors to make sense of complex topics, and that models can lead to bad decisions.