Diagnostic Cascade: A Cautionary Tale



Today’s managing health care cost indicator is 2.8 million


I was at a celebration of the end of the academic year last night at Harvard School of Public Health, and a former student told me a cautionary story.

She mentioned that her dad is very careful about his diet – ever since he had a CT-angiogram that showed calcium – indicating a high likelihood of heart disease.    He had no symptoms –and had the test because a friend, a radiologist, had this new machine and offered to test it on him.

2.8 million Americans were expected to get coronary CT scans in 2009. 

I listened, and mentioned that although her dad got radiation he shouldn’t have gotten –since the test was inappropriate – at least it led him to change his diet and make his life healthier.  (The likelihood of cancer due to the radiation from this exam is about 5 per 10,000 for a 60 year old man – but would be substantially higher for women). 

Alas, she told me, the story was much more complicated.

Based on the CT scan results, he had a cardiac catheterization, which demonstrated blockage of multiple vessels.  He had stents inserted, and was discharged home promptly. 

Then, the trouble started.   

He had bleeding and pain from the femoral artery – where the catheter was inserted for his procedure.  He had multiple exploratory surgeries for this – and eventually an errant stitch was removed. He was readmitted to the hospital multiple times over a period of almost half a year for a variety of complications from the stent placement – including one episode where he fainted just a few hours after his initial discharge.  He limped for years afterward.

My student’s dad is doing well now – he’s had no angina, and he watches his diet carefully and exercises.  

But at multiple levels, the health care system failed him

·       He had an initial screening test that was not indicated – since he had no symptoms of cardiac disease.  Here’s a link to a NEJM editorial about coronary CT scanning. 
·       He had a procedure to fix the incidentally-found asymptomatic heart vessel blockages. There is no evidence that a procedure to open up heart blood vessels prolongs life, but such procedures do relieve symptoms of angina – which he did not have. 
·       An error was made during his catheterization, leading to multiple complications which had a profound impact on his life.

If you’re wondering, the cardiologist who apparently made the medical error never apologized.   A subsequent surgeon explained that there had been a medical error, and then denied he said that. 

Anecdotes don’t usually make good policy – but this is a great example of a diagnostic cascade.  An initial ‘noninvasive’ test suggests unexpected disease – and it’s hard for clinicians and patients to stop until the disease (or the patient) is vanquished.  

The personal cost of misuse of medical technology to my student’s father was enormous.  The cost of his health care misadventure was pretty large too.