Last week, the Archives of Internal Medicine published a heartbreaking case study that illustrates the potential harms of undergoing medical testing simply to be reassured that everything is OK.

It’s an example (albeit an extreme one) that shows the dangers of “false positives” — test results that suggest the presence of a disease that isn’t really there.

A 52-year-old nurse showed up at the emergency department of her local community hospital complaining of chest pain. After a physical examination, an electrocardiogram (which was normal) and heart-related blood tests (again, normal), she was diagnosed as having “atypical chest pain most likely of musculoskeletal origin.” In other words, the examining doctors believed the pain in her chest was the result of sore muscles, not a bad heart. (The woman had begun an exercise program several weeks earlier in an attempt to lose weight and lower her blood pressure.)

“With few cardiac risk factors and an atypical chest pain presentation, this patient had a low pretest probability for coronary artery disease and should have been reassured and not undergone any further risk stratification [tests],” writes the author of the case study, Dr. Steven Nissen of the Cleveland Clinic in Ohio.

But instead the doctors decided to reassure the woman by having her undergo a noninvasive cardiac computed tomography angiography (CCTA) test, an imaging procedure that looks for signs of blockages or other trouble in the blood vessels of the heart. (It's also a test that has been found to be overused.) And that’s when things started to go terribly wrong. The CCTA test came back positive, so the doctors recommended coronary angiography, a procedure that uses a small flexible tube (catheter), inserted either through the groin or the arm, to explore the chambers of the heart. The angiography revealed no evidence of serious heart disease, a finding that meant the CCTA results had been erroneous. But, tragically, the woman experienced a rare complication during the procedure — a tear to an artery.

The doctors performed emergency heart bypass surgery. The woman was in the hospital for two weeks. But her condition continued to deteriorate, and eight months later she was back in surgery, this time for a heart transplant.

Yes, a heart transplant.

“In conclusion,” writes Nissen, “our patient suffered a rare but devastating complication from an cardiac catheterization that was the direct result of unnecessary CCTA and false-positive findings.”

Less is more
The Archives of Internal Medicine published this case study as part of its ongoing “less is more” series, which is attempting to demonstrate to doctors (and patients) that “more treatment is not necessarily better,” explains the journal’s editor, Dr. Rita Redberg, in an accompanying editorial.

“Often, diagnostic tests are ordered without questioning how the result will or should change patient treatment,” writes Redberg. “Instead, tests are ordered to ‘reassure,’ ‘just to be sure,’ ‘just in case,’ or ‘just to know.’ Among the problems, beyond the waste of resources, is that the likelihood ratios of many commonly ordered tests are not high enough to rule diagnoses in or out accurately in real-world settings. The result is that abnormal findings on one unneeded test often require another more invasive test or treatment. This cascade can result in a patient sustaining serious adverse effects from a simple blood test or imaging procedure that may have been thought to carry no risk at all.”

The nurse’s story “illustrates dramatically and tragically why we must reevaluate how we look at diagnostic tests,” adds Redberg. “In her physicians' good-faith attempts to ‘reassure’ this middle-aged woman that she did not have heart disease, they ordered a cardiac CT scan. This test, with known adverse effects, was unnecessary because the woman's prior probability of having serious cardiac disease was too low for a positive result to change her clinical treatment. Yet, sadly, the test was given more credit than it deserved, with the result that a healthy woman with a normal heart required a heart transplant, hardly the reassuring outcome that was intended.”

“[T]here are safer ways to reassure patients,” Redberg concludes. “Physicians are (still) highly respected professionals, and patients value our advice. Talking with our patients should be our first choice for reassurance; tests should be reserved for cases in which the benefits can be reasonably expected to outweigh the risks. This case reminds us that no test (not even a noninvasive one) is benign, and often less is more.”

You'll find the case study here and the editorial here.