Abstract 15490: Prognostic Value and Accuracy of Vasodilator Stress Cardiac MRI and 320-Row Coronary CTA
Objective: To assess the prognostic value and accuracy of vasodilator stress cardiac MRI (CMR) and 320-row coronary CTA in patients with suspected coronary artery disease (CAD).
Background: Vasodilator stress CMR detects ischemia, whereas coronary CTA detects atherosclerosis. The accuracy and prognostic value of these two state-of-the-art non-invasive imaging techniques is not known in the same subjects.
Methods: We studied 151 consecutive subjects with suspected CAD and a predominantly intermediate pre-test disease risk prevalence. Vasodilator stress CMR was performed on a 1.5 Tesla scanner and was classified as normal or ischemic. CTA was performed on a 320-slice scanner and was classified as obstructive CAD (≥50% or unevaluable) or non-obstructive. The reference standard was quantitative invasive angiography and follow-up for major adverse cardiovascular events.
Results: Subjects averaged 56±12 years and 60% were men. The median time between CTA and CMR examinations was 0 days (interquartile range 0-8 days). Follow-up duration averaged 450±115 days and was obtained in 100% of subjects. Overall, 42 subjects (28%) had invasive angiography and 29 major cardiac events occurred (1 death, 2 non-fatal myocardial infarctions, 11 percutaneous interventions and 15 coronary artery bypass surgeries, and no strokes). The event free survival (see Figure) was 97% for non-ischemic and 41% for ischemic CMR (p<0.0001) and 99% for non-obstructive and 40% for obstructive CTA (p<0.0001). Using invasive angiography and follow-up to detect any missed cases, CMR and CTA had a sensitivity of 93%, 98%; specificity of 96%, 96%; positive predictive value of 91%, 91%; negative predictive value of 97%, 99%; and accuracy of 95%, 97%, respectively.
Conclusion: Non-ischemic vasodilator stress CMR or non-obstructive coronary CTA each confer an excellent prognosis. Both CMR and CTA are accurate for the assessment of obstructive CAD in a predominantly intermediate risk population.
- © 2011 by American Heart Association, Inc.