The purpose of this study is to find a non-invasive alternative (with using ECG gated 64-slice CT angiography) to invasive coronary angiography for detecting coronary lesions in patients who had undergone arterial switch operation for transposition of the great arteries

Objectives To find a non-invasive alternative (with using ECG-gated 64-slice CT angiography) to invasive coronary angiography for detecting coronary lesions in children who had undergone arterial switch operation for transposition of the great arteries.

Background Assessment of the integrity of reimplanted coronary arteries is crucial for long-term outcome after arterial switch operation for transposition of the great arteries. Non-invasive tests have limited accuracy for detecting coronary lesions, and invasive coronary angiography is usually required in this setting.

Materials and methods Patients (age 4 to 30 years old) who undergone arterial switch operation in neonate period are potentially eligible. They will be prospectively included in the study. They will have both examinations, their routine invasive coronary angiography and ECG-gated 64-slice CT angiography. The ability of CT to detect lesions of the ostia and proximal segments of the reimplanted coronary arteries was analyzed by blinded comparison to invasive coronary angiogram.

Expected results and clinical implications We expect to demonstrate that ECG-gated 64-slice CT angiography is safe and accurate for the detection of coronary lesions with a high sensitivity (expected sensitivity>95%) as compared to invasive angiography. In that condition, ECG-gated 64-slice CT angiography could replace the invasive coronary angiography for the follow-up of patients with reimplanted coronary arteries after arterial switch operation for transposition of the great arteries.

Inclusion criteria :

• patients, age 4 to 30 years old, who had undergone arterial switch operation for transposition of the great arteries, are eligible.

Exclusion criteria :

• No consent
• Allergy to contrast agent (iodine contrast)
• Severe renal failure (clearance < 80ml/min/1.73m²)
• Severe arrhythmias
• Absence of medical care insurance
• Pregnancy
• Contre-indication to beta-blockers