Methods. From a registry of 1915 consecutive, all-comers, patients who underwent a clinically indicated IVUS evaluation of coronary plaques we enrolled 59 patients who underwent CCTA with a 64-slice CT (Group 1) and 59 patients who underwent CCTA with a last generation whole-heart coverage CT scanner (Group 2). Patients who underwent CCTA with unfavourable heart rhythm were not excluded from the analysis. Image quality (4-point Likert scale) focused on plaque analysis was evaluated. Plaque volume quantification by CCTA was compared to IVUS. Radiation dose for CCTA was recorded.
Results. No difference in clinical characteristics was found between Group 1 and 2. Plaque volume quantification by CCTA was considered not feasible in 13 plaques of Group 1and in 5 plaques of Group 2 (p =0.07). Higher correlation for plaque volume quantification by CCTA vs. IVUS was demonstrated in Group 2 when compared with Group 1 (r=0.9888 vs. 0.9499; p<0.0031). Bland-Altman analysis showed plaque volume overestimation by CCTA of 12.5 mm3 in Group 1and 4 mm2 in Group 2. Effective radiation dose of CCTA was significantly lower in Group 2 vs. Group 1 (2.7±0.9 mSv vs. 8.1±3.6 mSv, respectively; p<0.001).
Conclusions. CCTA using a new scanner generation showed to be an accurate non-invasive tool to assess and quantify coronary plaque volume (Figure 1)