BACKGROUND:

In the context of percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO), coronary CT angiography (CTA) may provide information on lesion length, degree of calcification, vessel tortuosity and optimal fluoroscopic angulations to visualize coronary segments without foreshortening. Whether image fusion of coronary CTA and fluoroscopic images during CTO-PCI may influence recanalization success and procedural parameters has not been investigated.

METHODS:

A consecutive cohort of 51 patients underwent routine coronary CTA (3^rd generation Dual Source CT) prior to elective PCI for CTO (mean age 64±9 years, 84% male, mean Syntax II score 33±7, mean J-CTO score 3.1±0.8, mean CTA-derived CTO length 33±15 mm, see table). Patients were subsequently randomized conventional CTO PCI (n=23, angiography group) versus the use of image fusion between fluoroscopy and coronary CTA (n=28, CT group).  In the CT group, the PCI operator could elect to have CT data displaying vessel anatomy as well as the degree of foreshortening projected in real-time onto the fluoroscopic image (syngo CTO Guidance, Siemens Healthineers, Forchheim, Germany), enabling the operator to optimize C-arm angulation and guidewire strategy. CTO success rate (restoration of TIMI flow grade II or III), 30-minute wire crossing rate, and procedural parameters including time to achieve wire crossing, total procedure and fluoroscopy time, dose area product and amount of contrast medium were compared between the two groups.

RESULTS:

There were no significant differences between the CT and angiography groups regarding baseline characteristics (see table). Both in the CT and angiography group, antegrade recanalization was performed in most cases (96% vs. 95%, p=0.89). Overall CTO recanalization success was 86% (CT: 93%, angiography: 78%, p=0.14). Total procedure time, amount of contrast and dose area product were not significantly different between the CT and angiography group (see table). Number of guidewires per patient was not different between the two groups (CT: 3±2/patient, angiography: 4±3/patient, p=0.09). Wire crossing within 30 minutes was achieved in 25/16 patients (CT: 89%, angiography: 70%, p=0.081). Mean wiring time was significantly shorter in the CT vs. angiography group (10±11 vs. 26±27 min., p=0.004) and mean fluoroscopy duration was significantly lower (27±15 vs. 43±28 min., p=0.014). No MACE (death, myocardium infarction, target vessel PCI, pericardiocentesis or stroke) occurred during the hospital stay.  

CONCLUSION:

Image fusion of coronary CTA and fluoroscopy may provide useful guidance for PCI of chronic total coronary occlusions and results in shorter wiring time and fluoroscopy duration as compared to conventional angiography-assisted CTO recanalization.