Prevalence of obstructive coronary artery disease in an outpatient cardiac CT angiography environment

Among ambulatory patients referred for CT angiography with symptoms or positive (or equivocal) cardiac stress tests, 73% of patients were found to have either normal coronary arteries or non-obstructive disease. Given the high negative predictive power of cardiac CTA (93-99%), these patients most likely would not require subsequent invasive coronary angiography. A strategy of selective cardiac catheterization may substantially decrease unnecessary diagnostic cardiac catheterizations and reduce health care expenses.