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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(Lack of ) Quality of nutritional supplements

(Lack of ) Quality of nutritional supplements

In my last post, I blogged about how we must not confuse marketing with truth. They are often two different things.

A patient I saw today was absolutely convinced that his fish oil was the best available in the world: purer, uncontaminated by mercury or pesticides--"not like that other crap on the shelves." I asked him how he knew this. "They say so," he proudly declared.

Do you recognize this? He fell for the marketing. While there may be some truth in the manufacturer's claims, you can't believe it from the mouth of the manufacturer. True judgements about quality and purity have to come from an independent source like Consumer Reports, Consumer Lab, or the FDA.

But the FDA doesn't regulate the quality and purity of nutritional supplements. On the positive side, this has allowed supplement manufacturers to keep costs down, not having to navigate arcane and complex regulatory restrictions.

On the negative side, a fair number of supplement manufacturers get away with 1) producing supplements that fail to contain the stated amounts of ingredients, occasionally containing none of the essential ingredient(s), 2) contain contaminants like lead, and 3) make extravagant and often unfounded claims like "superior", "more effective", and "purer". (DHEA, for instance, is a particular landmine of poor quality. I recently suggested that a patient take DHEA; despite consistently taking 50 mg of a specific brand for several months, the blood level of DHEA-S didn't budge one bit--there was likely little or none in the capsule.)

The Fanatic Cook at http://fanaticcook.blogspot.com has posted some very insightful discussions on this issue and the proposed FDA regulations of supplements. They're worth perusing.

I really wish regulation weren't necessary and that the industry could have policed itself. But it clearly has failed and perhaps federal oversight is not such a bad thing, as long as the FDA regulations restrict themselves to oversight over quality and purity and not to efficacy. It's the efficacy regulation that could hogtie innovation in supplement development.
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