Abstract
Background
Coronary artery calcifications are frequently observed in patients referred for cardiac catheterization. Using OCT, the calcified volume can be determined. CT is a sensitive non-invasive tool to detect coronary artery calcifications and may be useful to guide percutaneous coronary intervention.
Purpose
The aim of the study was to investigate the accuracy of CT-derived calcium volume with OCT as a reference in patients undergoing PCI.
Methods
66 calcified plaques (32 vessels) from 31 patients undergoing OCT-guided PCI with coronary CT angiography acquired as a standard of care were included. Coronary CT angiography and OCT images were matched using fiduciary points. Calcified plaques were reconstructed in three dimensions to calculate calcium volume. A Passing-Bablok regression analysis and the Bland-Altman method were used to assess agreement between imaging modalities.
Results
27 left anterior descending arteries and 5 right coronary arteries were analyzed. Median calcium volume by CT angiography and OCT were 18.23 mm 3 [IQR 8.09, 36.48] and 10.03 mm 3 [IQR 3.6, 22.88]. The Passing-Bablok analysis showed a proportional difference without a systematic difference (Coefficient A 0.08, 95% CI: −1.37 to 1.21, Coefficient B 1.61, 95% CI: 1.45 to 1.84); with a mean difference of 9.69 mm3 (LOA −10.2 mm 3 to 29.6 mm 3). No significant differences were observed for MLA: median value for CT 2.84 mm2 [IQR 2.03, 3.74] and for OCT 2.55 mm2 [IQR 1.91, 4.43].
Conclusions
Coronary CT angiography volumetric calcium evaluation overestimates calcium volume by 60% compared to OCT. Accounting for CT overestimation may allow for appropriate interpretation of calcific burden in the non-invasive setting. Coronary CT angiography may emerge as a tool to quantify calcium burden for invasive procedural planning.
Calcium burden comparison CT vs OCT
Funding Acknowledgement
Type of funding source: None