The Nation's Health + health

Your heart scan is just a "false positive"

I've seen this happen many times. Despite the great media exposure and the growing acceptance of my colleagues, heart scans still trigger wrong advice. I had another example in the office today.

Henry got a CT heart scan in 2004. His score: 574 . In his mid-50s, this placed him in the 90th percentile, with a heart attack risk of 4% per year. Henry was advised to see a cardiologist.

The cardiologist advised Henry, "Oh, that's just a 'false positive'. It's not true. You don't have any heart disease. Sometimes calcium just accumulates on the outside of the arteries and gives you these misleading tests. I wish they'd stop doing them." He then proceeded to advise Henry that he needed a nuclear stress test every two years ($4000 each time, by the way). No attempt was made to question why his heart scan score was high, since the entire process was outright dismissed as nonsense.

I'm still shocked when I hear this, despite having heard these inane responses for the past decade. Of course, Henry's heart scan was not a false positive, it was a completely true positive. I'm grateful that nothing bad happened to Henry through two years of negligence, though his heart scan score is likely around 970 , given the expected, untreated rate of increase of 30%.

The cardiologist did a grave disservice to Henry: He misled him due to his ignorance and lack of understanding. I wish Henry had asked the cardiologist whether he had read any of the thousands of studies now available validating CT heart scans. I doubt he's bothered to read more than the title. The cardiologist is lucky (as is Henry) that nothing bad happened in those two years.

Do false positives occur as the cardiologist suggested? They do, but they're very rare. There's a rare phenomenon of "medial calcification" that occurs in smokers and others, but it is quite unusual. >99% of the time, coronary calcium means you have coronary plaque--even if the doctor is too poorly informed to recognize it.

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