Abstract 12911: Has Low Attenuation Plaque Volume in Coronary Computed Tomographic Angiography an Incremental Value For Prediction of Cardiac Events?
Background: Coronary plaques with low attenuation in coronary computed tomographic angiography (CCTA) are supposed to be indicative of vulnerable plaques and to be particularly prone to plaque rupture and subsequent cardiac events. Nevertheless, plaque characterization is time consuming and technically challenging and it is not known whether it is better than simple plaque counting.
Methods: We performed a characterization of 848 coronary segments with noncalcified or mixed plaques in 311 patients undergoing CCTA from October 2004 to September 2006. The volume of low attenuation plaque (LAP, density<30HU) and intermediate attenuation plaque (IAP, 30HU<density<150HU) was calculated automatically after manual plaque delineation. For comparison a plaque score counting segments with noncalcified or mixed plaques was calculated. Clinical follow up was performed after a median of 3.2 years. Primary endpoint of the study was a composite of all cause death, myocardial infarction and coronary revascularization later than 90 days after CCTA.
Results: Total LAP volume was higher in patients reaching primary endpoint (315±211 ml vs. 182±139 mm^3) and significantly correlated with outcome (p=0.005). For total IAP volume the correlation was weaker but still significant (488±344 ml vs. 312±231 mm^3, p=0.038). Nevertheless, compared with the simple plaque score, there was no additional prognostic value for LAP (p=0.35) or IAP (p=0.82)
Conclusions: Low attenuation plaque volume has a good predictive value for subsequent cardiac events, but it adds no significant prognostic information to a simple score counting segments with noncalcified or mixed plaques.
- © 2010 by American Heart Association, Inc.