While Edgar Allen Poe wasn't referring to the proper test to assess asymptomatic, at-risk patients for coronary artery disease (CAD), the sentiment still applies. Although SPECT is often touted as the most popular choice for screening this patient population, other tests could produce better outcomes.
This week, the Journal of the American Medical Association released a randomized, controlled trial of more than 1,000 patients with type 2 diabetes and no symptoms of CAD, who were screened either with SPECT MPI or not screened at all and tracked for five years. The researchers found that the patients did not experience a significant reduction in the rate of heart attacks or cardiac death, compared to patients who were not screened.
However, the authors suggested that rather than "viewing this study as a negative screening study," clinicians should consider closer follow-up and monitoring of this patient population.
On the other hand, cardiac imaging expert Dr. Daniel Berman told Cardiovascular Business News that the researchers used the wrong test. He recommended that a coronary artery calcium (CAC) score with non-contrast CT, which is less expensive than SPECT MPI, would have better predicted those at risk of future cardiac events. Also, Berman suggested that diabetics are often "grouped together," but in actuality, 30 percent of the diabetic population little or no calcium, and therefore, are at less risk for heart attacks than the other 70 percent. The 30 pecent could breathe easier knowing they are at a low risk with a simple calcium test.
The topic of imaging the right patient with the right test will continue in the upcoming issue of Cardiovascular Business magazine, in which a collection of luminaries in the field of nuclear cardiology discuss the intricacies of SPECT imaging in a roundtable setting.
While the question of screening asymptomatic, at-risk patient populations will continue to unfold, with each tool having it's advocates, Poe's encouragement to evaluate their true "merit" might provide a helpful standard.
On these topics, or any others, feel free to contact me.