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- Michael S. Lauer, MD⁎ ()
- ↵⁎Office of the Director, Division of Cardiovascular Sciences of the National Heart, Lung, and Blood Institute, 6701 Rockledge Drive, Room 8128, Bethesda, Maryland 20892
In their thoughtful letter, Drs. Kuller and Edmundowicz challenge my call for randomized trials of coronary artery screening (1). They cite U.S./United Kingdom ecological data demonstrating public health benefits from prostate-specific antigen (PSA) screening (2) and then cite a just-published randomized trial that found reduced mortality (3). They argue that, in our current environment, it is impractical to execute trials, and even so, they are unnecessary: we already know lipid-lowering therapy works.
Numerous authorities have cited the limitations of observational analyses of screening; these include lead- and length-time bias, misattribution bias, and overdiagnosis. Even Collin et al. (2), who wrote the positive ecological study that Kuller and Edmundowicz cite, conclude their report stating, “We can only continue to speculate about the relative contributions of differences in detection and treatment or the relative balance of benefits and harms, until the publication of findings from trials provides the robust evidence that is so eagerly awaited.” I agree!
Prostate cancer kills far less often than coronary artery disease, yet academic leaders have completed large-scale trials. Two trials that enrolled approximately 250,000 patients showed little or no benefit and much overdiagnosis, whereas 1 trial an order of magnitude smaller suggests benefit in some patients (3). Academic leaders have performed screening trials for other less common diseases, including breast cancer, lung cancer, and aortic aneurysm. Surely we can execute a screening trial for coronary disease, the nation's leading cause of death.
Drs. Kuller and Edmundowicz suggest that high background rates of screening will contaminate an American trial. Lu-Yao et al. (4) reported on an intra-American natural experiment and found no association between regional rates of PSA screening and prostate cancer mortality.
I am not calling for another trial of lipid-lowering therapy but for a trial of coronary screening. Yes, there are differences between screening for prostate cancer and for coronary disease. The PSA screening has no intrinsic harms, whereas cardiac computed tomography carries with it small but real risks from radiation and incidental findings. We should require higher levels of evidence that the net benefits of coronary screening are real, not theoretical. As Lord et al. (5) eloquently articulated, we cannot assume that, just because a diagnostic test predicts disease, it prevents it.
- American College of Cardiology Foundation
- Lauer M.S.
- Lu-Yao G.,
- Albertsen P.C.,
- Stanford J.L.,
- Stukel T.A.,
- Walker-Corkery E.S.,
- Barry M.J.