Abstract 18866: Vasodilator Stress Cardiac MRI: How Does it Compare with 320-slice Coronary CTA?
Objective: To assess and compare the diagnostic accuracy of vasodilator stress cardiac MRI and 320-slice coronary CTA in patients with suspected coronary artery disease (CAD).
Background: Vasodilator stress cardiac MRI detects ischemia, whereas coronary CTA detects atherosclerosis. How these two state-of-the-art non-invasive imaging techniques compare is unknown.
Methods: 151 subjects with suspected CAD completed both CTA and vasodilator MRI utilizing dipyridamole or regadenoson with first pass gadolinium enhanced imaging. CMR was performed on a 1.5 Tesla scanner and studies were classified as normal or ischemic (presence of stress induced perfusion defects). Coronary CTA was performed on a 320-slice scanner and studies were classified as having non-obstructive (<50%) or obstructive CAD (≥50% or unevaluable due to dense calcification). Studies were read blinded. In a subset of 35 subjects, invasive coronary angiography defined the presence of obstructive CAD involving a major coronary vessel and findings were used to adjudicate the gold standard for CAD to minimize errors from false positive or false negative studies. Data were analyzed on a per patient basis.
Results: Subjects averaged 55.8±11.8 years and 61 were men (40.3%). Median time between the MRI and CTA exams was 0 days (interquartile range 0–8.8). The Cohen kappa coefficient between CMR and CTA was 0.855, p<0.001. When using invasive angiography to adjudicate CTA as the gold standard for CAD, MRI had a sensitivity of 88%, specificity 96%, positive predictive value (PPV) 90%, negative predictive value (NPV) 95% and accuracy 94%. When adjudicated CMR was used as the gold standard, CTA had a sensitivity of 95%, specificity 94%, PPV 85%, NPV 98% and accuracy 98%.
Conclusion: Vasodilator stress MRI and coronary CTA findings strongly correlate, and both tests are accurate for the assessment of obstructive CAD in a low to intermediate risk population.
- © 2010 by American Heart Association, Inc.