Comparison of coronary angiography-assisted and computed coronary tomography angiography-assisted recanalisation of coronary chronic total occlusion.

Background: Computed coronary tomography angiography (CCTA) provides an alternative to coronary angiography (CAG) and a complementary way of imaging.

Objective: To determine whether CT assistance might help increase the recanalisation rate of coronary chronic total occlusion (CTO).

Method: Two experienced physicians took part in the study-one specialised in both CCTA and percutaneous coronary intervention (PCI), and the other had PCI experience only and no knowledge of CCTA. Consecutive patients were enrolled if CTO was diagnosed by CAG or by CCTA. The images were analysed on a dedicated work station which examined the length and characteristics of the occlusion, the calibre of the artery, the best projection for precision guidewire penetration, the use of a side branch and calcification for landmarking and selection of most suitable guidewires. Patients underwent CAG-guided PCI or CCTA-assisted PCI. The main end point was the recanalisation rate. Secondary end points included the time for successful passage of the guidewire, fluoroscopy time, and contrast, guidewire and stent consumption.

Results: Thirty-six patients underwent CAG and 44 CCTA. The clinical characteristics and laboratory data of the two groups were similar (p>0.05). The patients in the CCTA group had more complex disease than those in the CAG group as shown by the J-CTO score (Multicenter CTO Registry of Japan) (p<0.05). Recanalisation was possible in 75.8% of the CAG group and 72.1% of the CCTA group. However, no statistical significance was found, p>0.05. In five of seven patients who had undergone unsuccessful PCI previously the procedure was successful at the second attempt when CCTA-assisted PCI was used. The patients were divided into those for whom the procedure was a failure or a success. The J-CTO score was an independent predictor of failure (OR=0.290, 95% CI 0.158 to 0.533).

Conclusion: CTO with favourable characteristics does not need CCTA guidance, but CCTA can be used to recanalise CTO with unfavourable characteristics when the procedure has previously failed. ACTRN12611000368932.