title: Left atrium and pulmonary vein imaging using sub-millisiviert cardiac computed tomography: Impact on radiofrequency catheter ablation cumulative radiation exposure and outcome in atrial fibrillation patients.
abstract: BACKGROUND
  The outcome of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has improved thanks to left atrium (LA) anatomy reconstruction by cardiac computed tomography (CCT). A new model-based iterative reconstruction algorithm (MBIR) provides image noise reduction achieving effective radiation dose (ED) close to chest X-ray exposure. Aim of this study was comparing RFCA procedural characteristics, AF recurrence and radiation exposure between patients in whom RFCA was guided by CCT image integration with MBIR versus a CCT standard protocol.
  
  
  METHODS
  Three-hundred consecutive patients with drug-refractory AF were studied with CCT using MBIR (Group 1; N:150) or CCT with standard protocol (Group 2; N:150) for LA evaluation and treated by image integration-supported RFCA. Image noise, signal to noise ratio (SNR), contrast to noise ratio (CNR), RFCA procedural characteristics, rate of AF recurrence and radiation exposure were compared.
  
  
  RESULTS
  Group 1 showed higher SNR (25.9±7.1 vs. 16.2±4.8, p<0.001) and CNR (23.3±7.1 vs. 12.2±4.2, p<0.001) and lower image noise (22.3±5.2 vs. 32.6±8.1 HU, p<0.001), fluoroscopy time (21±12 vs. 29±15min, p<0.01) and procedural duration (135±89 vs. 172±55, p<0.001). Group 1 showed a 94% reduction of ED as compared to Group 2 (CCT-ED related: 0.41±0.04 vs. 6.17±4.11mSv, p<0.001; cumulative CCT+RFCA-ED related: 21.9±17.9 vs. 36.0±24.1mSv, p<0.001) with similar rate of AF recurrence (25% vs. 29%, p=0.437).
  
  
  CONCLUSIONS
  CCT with MBIR allows accurate reconstruction of LA anatomy in AF patients undergoing RFCA with a sub-millisievert ED and comparable success rate of RFCA as compared to a standard CCT scan protocol.
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy. Electronic address: gianluca.pontone@ccfm.it.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pontone
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Cardiovascular Sciences and Community Health, University of Milan, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Andreini
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Petulla
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Annoni
authors.affiliation: Department of Cardiology, University of Foggia, Italy.
authors.forename: Andrea I
authors.initials: AI
authors.lastname: Guaricci
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Ester
authors.initials: E
authors.lastname: Innocenti
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Russo
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Guglielmo
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Saima
authors.initials: S
authors.lastname: Mushtaq
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Baggiano
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Virginia
authors.initials: V
authors.lastname: Beltrama
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fusini
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Segurini
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Conte
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Formenti
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Fassini
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Riva
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Tondo
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Cardiovascular Sciences and Community Health, University of Milan, Italy.
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy; Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, Italy.
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Bartorelli
authors.affiliation: Centro Cardiologico Monzino, IRCCS, Milan, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Pepi
mesh_terms: D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000601:surgery; D017115:Catheter Ablation; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000000981:diagnostic imaging*; D000069079:Radiation Exposure; D012008:Recurrence; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: Ablation; Atrial fibrillation; Iterative reconstruction algorithm; Outcome; Radiation exposure