Diagnostic Accuracy of Dual-Source Multislice Computed Tomographic Analysis for the Preoperative Detection of Coronary Artery Anomalies in 100 Patients With Tetralogy of Fallot

Study Questions:

What is the accuracy of dual-source computed tomography (DSCT) for diagnosis of coronary anomalies prior to surgical repair of tetralogy of Fallot in infants and children?

Methods:

A prospective study was performed at a single institution. As part of standard of care, 100 consecutive patients underwent DSCT prior to repair of tetralogy of Fallot, in addition to routine echocardiography. A helical protocol was used for 42 patients, and a prospective sequential protocol was used in 58 patients.

Results:

The median age at repair was 6.8 months (range 1.2 months to 6.8 years). Coronary artery abnormalities were noted in seven (7%) patients. Compared with surgical findings, DSCT had a sensitivity and specificity of 100% for detection of coronary artery abnormalities. The mean effective radiation dose for the prospective sequential protocol was relatively low at 0.46 mSv, as compared with 1.49 mSv for the helical protocol. Coronary abnormalities included anomalous left anterior descending artery arising from the right coronary artery in four patients, and a single coronary artery in three patients.

Conclusions:

The authors concluded that DSCT is an accurate and noninvasive tool for delineating coronary artery abnormalities prior to surgical intervention in children with tetralogy of Fallot. DSCT might be used in place of coronary angiography and in combination with echo studies to evaluate coronary anatomy prior to tetralogy repair.

Perspective:

The presence of coronary artery abnormalities, particularly coronary arteries crossing the right ventricular outflow tract, has important implications for the repair of tetralogy of Fallot. It is essential that the coronary artery anatomy be accurately evaluated prior to surgical intervention for patients with tetralogy of Fallot. In experienced congenital echocardiography laboratories, echocardiography is a highly sensitive and specific modality for detection of coronary anomalies (Need LR, et al. J Am Coll Cardiol 2000;36:1371-7), and is the only imaging tool necessary in the vast majority of patients. This study shows excellent accuracy of coronary CT in 100 consecutive patients undergoing surgical repair of tetralogy of Fallot. Because of the high risk of exposure to ionizing radiation in young patients, routine preoperative coronary CT is not justifiable, despite the relatively low radiation doses used in the study. DSCT should be reserved for patients in whom the echocardiogram has not adequately diagnosed coronary anomalies, and coronary angiography may have been considered for definitive diagnosis.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Congenital Heart Disease, CHD & Pediatrics and Imaging, CHD & Pediatrics and Interventions, Interventions and Imaging, Interventions and Structural Heart Disease, Angiography, Computed Tomography, Echocardiography/Ultrasound, Nuclear Imaging

Keywords: Tetralogy of Fallot, Radiation, Ionizing, Heart Defects, Congenital, Coronary Angiography, Tomography, X-Ray Computed, Multidetector Computed Tomography, Coronary Vessels, Echocardiography


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