title: Usefulness of cardiac computed tomographic delayed contrast enhancement of the left atrial appendage before pulmonary vein ablation.
abstract: Left atrial appendage (LAA) contrast filling defects are commonly found in patients undergoing multidetector cardiac computed tomography (CCT) before catheter ablation of atrial fibrillation. Delayed CCT allows quantification of the LAA delayed/initial attenuation ratio and improves accuracy for LAA thrombus detection, which may obviate routine transesophageal echocardiography (TEE) before ablation. CCT with contrast-enhanced scans (initial CCT) and with noncontrast-enhanced scans (delayed CCT) was performed in 176 patients. LAA was evaluated for filling defects. LAA apex, left atrial (LA) body, and ascending aorta (AA) attenuations (Hounsfield units) were measured on initial and delayed cardiac computed tomograms to calculate LAA, LA, LAA/LA, and LAA/AA attenuation ratios. LAA, initial LAA/LA, and initial LAA/AA attenuation ratios differed significantly in patients with versus without filling defects on cardiac computed tomogram, those with atrial fibrillation versus normal sinus rhythm, and those with abnormal left ventricular ejection fraction versus larger LA volumes (p <0.05). In 70 patients (40%) who underwent TEE, 13 LAA filling defects were seen on initial cardiac computed tomogram. Two defects persisted on delayed cardiac computed tomogram and thrombus was confirmed on transesophageal echocardiogram. Sensitivity, specificity, and positive and negative predictive values of initial CCT for LAA thrombi detection were 100%, 84%, 15%, and 100%, respectively. With delayed CCT these values increased to 100%. Intraobserver and interobserver reproducibilities for cardiac computed tomographic measurements were good (intraclass correlation 0.72 to 0.97, kappa coefficients 0.93 to 1.00). In conclusion, delayed CCT provided an increase in diagnostic accuracy of CCT for detection of LAA thrombus in patients with atrial fibrillation before ablation, which may decrease the need for routine TEE before the procedure.
authors.affiliation: Zena and Michael A. Wiener Cardiovascular Institute, Mount Sinai School of Medicine, New York, New York, USA.
authors.forename: Simonette T
authors.initials: ST
authors.lastname: Sawit
authors.forename: Ana
authors.initials: A
authors.lastname: Garcia-Alvarez
authors.forename: Bhavna
authors.initials: B
authors.lastname: Suri
authors.forename: Juan
authors.initials: J
authors.lastname: Gaztanaga
authors.forename: Leticia
authors.initials: L
authors.lastname: Fernandez-Friera
authors.forename: Jesus G
authors.initials: JG
authors.lastname: Mirelis
authors.forename: Michael
authors.initials: M
authors.lastname: D'Anca
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuster
authors.forename: Javier
authors.initials: J
authors.lastname: Sanz
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Garcia
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging*; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D003287:Contrast Media; D017548:Echocardiography, Transesophageal; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D057234:Preoperative Period; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000601:surgery*; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media