Adela Rohnean

Diagnostic accuracy of dual-source multislice computed tomographic analysis for the preoperative detection of coronary artery anomalies in 100 patients with tetralogy of Fallot

OBJECTIVES A detailed preoperative evaluation of coronary anatomy is mandatory before surgical intervention for tetralogy of Fallot. In pediatric patients, the preoperative evaluation of coronary anatomy has relied classically on conventional angiographic analysis and, more recently, on echocardiographic analysis, which have well-known limitations and complications. Recent technological improvements allow the use of multislice computed tomographic analysis to evaluate coronary artery anatomy in very young children, even those with high heart rates. The purpose of this prospective study was to assess the accuracy of preoperative dual-source computed tomographic analysis in detecting coronary artery abnormalities by using surgical findings as the reference standard. METHODS We prospectively evaluated 100 patients with tetralogy of Fallot before surgical intervention between November 2006 and September 2009 by using dual-source computed tomographic analysis with either retrospective, electrocardiographically gated, helical computed tomographic analysis or prospective, electrocardiographically triggered, sequential computed tomographic acquisition. The patients had a median age of 6.8 months (range, 1.2 months-6.8 years) and a median weight of 7.9 kg (range, 3-30 kg). RESULTS Compared with surgical findings, dual-source computed tomographic analysis had 100% sensitivity and 100% specificity for detecting coronary artery abnormalities. Major coronary artery abnormalities were found in 7 (7%) patients. The radiation dose was low. CONCLUSIONS Dual-source computed tomographic analysis is an accurate and noninvasive tool for delineating coronary artery anatomy before surgical intervention in children with tetralogy of Fallot. Dual-source computed tomographic analysis might deserve to be used routinely instead of angiographic analysis and in combination with echocardiographic analysis for the preoperative assessment of patients with tetralogy of Fallot.

Heart Transplant Patient Outcomes: 5-Year Mean Follow-Up by Coronary Computed Tomography Angiography

Backgrounds. We evaluate the feasibility and safety of coronary computed tomography angiography (CCTA) as the first-line investigation in heart transplant patients and the rate of coronary allograft vasculopathy detected using CCTA. Methods. From September 2003 to June 2009, we prospectively included 65 heart transplant recipients, retaining 62 who underwent yearly CCTA for coronary allograft vasculopathy detection (261 CCTAs). We used 16-slice, 64-slice, and 2×64-slice CT machines. Patients with coronary artery stenosis by CCTA had a confirmation and a further follow-up exclusively by conventional coronary angiography (CCA). Results. No major coronary events occurred during the study. Of the 62 baseline CCTAs, 37 (60%) were normal, 18 (29%) showed wall thickening, and 7 (11%) known significant stenosis, confirmed by CCA. The mean follow-up duration was 5 years. At the last follow-up, 26 (70%) patients with normal baseline findings remained normal, 9 (24%) had wall thickening, and 2 (6%) significant stenoses. Time to stenosis was consistently greater than 3 years. Of the 18 patients with initially wall thickening, 14 (78%) had wall thickening and 4 (22%) significant stenosis at last follow-up. The mean interval without any coronary lesion was 9.46±3.98 years. The mean interval without de novo significant stenosis was 10.31±4 years. Conclusions. CCTA seems to be a safe noninvasive tool for monitoring heart transplant patients, and thus obviating the need for CCA. In patients with normal baseline CCTA, a 2-year interval between CCTAs may be safe.

Diagnosis of Functionally Significant Coronary Stenosis with Exercise CT Myocardial Perfusion Imaging

PURPOSE To assess the feasibility of exercise perfusion computed tomography (CT) in patients suspected of having hemodynamically significant coronary stenosis. MATERIALS AND METHODS This study had institutional review board approval, and all patients gave informed consent. Thirty-two consecutive patients (26 men [mean age, 63 years] and six women [mean age, 71 years]) with 55 coronary stenoses of at least 50% underwent coronary CT angiography (one stenosis in 13 patients, two stenoses in 15 patients, and three stenoses in four patients). CT myocardial perfusion imaging was performed within 1 minute after patients performed supine exercise on an ergometer secured to the CT table. The pressure-rate product was computed to assess level of exercise. The myocardial enhancement ratio between stenotic and normally perfused territories was determined for each stenosis. Fractional flow reserve less than 0.8, as measured during invasive coronary angiography, was the reference for defining significant stenoses. Receiver operating characteristic curves were constructed to determine the myocardial enhancement ratio cutoff value. RESULTS In the per-patient analysis, a myocardial enhancement ratio cutoff of 0.8 performed best for identifying functionally significant stenosis: Sensitivity was 95% (21 of 22 patients), specificity was 90% (nine of 10 patients), positive predictive value was 95% (21 of 22 patients), negative predictive value was 90% (nine of 10 patients), and accuracy was 94% (30 of 32 patients). Corresponding values in the per-stenosis analysis were 97% (29 of 30 stenoses), 96% (23 of 24 stenoses), 97% (29 of 30 stenoses), 96% (23 of 24 stenoses), and 96% (52 of 54 stenoses), respectively. CONCLUSION Exercise CT myocardial perfusion imaging is feasible and accurate for assessment of the functional significance of coronary stenosis.

Bilan preoperatoire du fallot : interet du scanner multicoupe en mode sequentiel

Objectifs Realiser le bilan preoperatoire des enfants atteints de tetralogie de Fallot par realisation d’un scanner tout en maitrisant la dose d’irradiation par l’utilisation du mode sequentiel en scanner mulicoupe. Materiels et methodes L’etude porte sur une serie prospective de 38 jeunes patients qui ont ete operes d’une tetralogie de Fallot dans notre institution entre juillet 2007 et fevrier 2009. Les examens preoperatoires ont ete realises apres injection de contraste iode, en mode sequentiel, en adaptant les parametres d’acquisition au poids de l’enfant. Resultats L’evaluation morphologique a porte sur l’arbre arteriel pulmonaire, l’origine et le trajet des arteres coronaires, l’etude des malformations associees eventuelles (retours veineux pulmonaires et systemiques, arche aortique, compression bronchique). Trois anomalies d’origine des coronaires ont ete detectees, et diverses anomalies associees ont ete mises en evidence. Ces donnees ont ete confrontees aux constats per-operatoires. Conclusion Le scanner multicoupe en mode sequentiel permet de realiser, a moindre irradiation, une evaluation exhaustive des gros vaissaeux et des coronaires dans le bilan preoperatoire du Fallot avec une precision diagnostique elevee qui permet de surseoir a l’angiographie et de proposer un examen peu invasif compte tenu d’une irradiation diminuee.