J Cardiovasc Comput Tomogr. 2015 Jul-Aug;9(4):250-1. doi: 10.1016/j.jcct.2015.04.003. Epub 2015 Apr 21.
Budoff MJ1.
Although current guidelines start to include coronary CT angiography (CTA) for specific patient groups and indications, typically as “class IIa” recommendations, functional testing for ischemia is still recommended as the preferred test (class I indication) to risk stratify and identify patients with increased likelihood of coronary artery disease (CAD) before invasive coronary angiography. Unfortunately, most patients who undergo invasive angiography after ischemia testing have nonobstructive or normal arteries, so obviously diagnostic accuracy is low in current clinical practice.1 In an analysis of the National Cardiovascular Data Registry (NCDR), of 661,063 patients undergoing elective angiography, 386,003 (58.4%) did not have obstructive CAD. In that subset, the largest cohort had undergone myocardial perfusion imaging, and of 302,651 patients in whom myocardial perfusion imaging studies led to cardiac catheterization, only 134,670 (44.4%) had obstructive disease in invasive angiography. Exercise treadmill testing, stress echocardiography, and magnetic resonance imaging yielded similarly low rates of obstructive disease. In comparison, in the aforementioned NCDR, coronary CTA had been performed in 8323 patients and 5791 (70%) of these were found to have obstructive disease in invasive angiography, representing more than a 50% improvement in identifying patients with obstructive disease compared to any functional test (P < .001).