Stent sizing by coronary computed tomographic angiography: comparison with conventional coronary angiography in an experienced setting.

OBJECTIVES: The goal was to compare stent sizing by coronary computed tomographic angiography (CCTA) with that deployed in an experienced setting based upon conventional coronary angiography (CA). BACKGROUND: Stent sizing is currently performed by visual estimation, with infrequent guidance by intravascular ultrasound. CCTA permits quantitative determination of stent length (Stent L) and diameter (Stent D). METHODS: Projected L (CTA-Stent L) and D (CTA-Stent D) were determined from CCTA obtained in 248 patients with 352 lesions undergoing percutaneous coronary intervention within 4 months of the CCTA, and were compared to the Stent-L and Stent-D of the actually deployed stents. The effects of lesion modification and calcified plaque were also evaluated. RESULTS: There were significant correlations between CTA-Stent L and Stent L (r = 0.656, P < 0.0001) and between CTA-Stent D and Stent D (r = 0.40, P < 0.001). Median predicted CTA-Stent L was slightly longer (20 mm vs. 18 mm, P < 0.0001) and predicted CTA-Stent D was slightly smaller (3.0 mm vs. 3.2 mm, P < 0.0001) than Stent-L and Stent-D, respectively. The differences were unchanged in stents with lesion modification by pre-dilation or intracoronary nitroglycerin. CTA Stent-L and CTA Stent-D increased significantly with increasing calcium (P < 0.0001 and P = 0.019, respectively). CONCLUSIONS: (1) There are significant correlations between CCTA and CA based stent sizing in an experienced setting. (2) CCTA projects slightly longer and slightly smaller diameter stents than those deployed during PCI irrespective of lesion modification; the small differences are unlikely to have clinical significance. (3) CCTA may offer a noninvasive alternative to intravascular ultrasound for stent planning.