Copyright 2011 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2011
The letter by Dr Zilberberg emphasizes the importance of applying Bayesian thinking to decision making in selecting patients for diagnostic tests such as CCTA. We completely agree. Any appropriate analysis of the pretest likelihood of CAD in our patient would have concluded that she had a very low risk of CAD and should not have undergone CCTA. However, we disagree with sensitivity and specificity values assigned to CCTA in the Table included with the letter. We find the literature describing the utility of CCTA highly biased and overly optimistic about the true sensitivity and specificity of the procedure. Most published CCTA studies carefully selected patients to study, often excluding those in whom the test was likely to perform poorly. Our case illustrates the problem of the “herd mentality” in clinical practice in which overly optimistic initial reports by “true believers” result in overuse of incompletely studied diagnostic methods or therapies. We must also re-emphasize that CCTA is poorly suited to diagnostic decision making in patients with CAD, regardless of their pretest likelihood of disease. Obstructive coronary disease is ubiquitous in developed countries.1 The salient question in patients with chest pain of uncertain etiology is not whether any obstructive disease is present, but whether any observed obstructions are ischemia producing. Stress testing, with or without imaging, provides more useful information for the clinician in deciding whether invasive angiography is indicated.
Nissen SE. Consequence of Overuse of Invasive Coronary Angiography—Reply. Arch Intern Med. 2011;171(7):702-710. doi:10.1001/archinternmed.2011.113