Left atrial volume calculated by multi-detector computed tomography may predict successful pulmonary vein isolation in catheter ablation of atrial fibrillation.
OBJECTIVE
Catheter ablation (CA) of atrial fibrillation (AF) might be a definitive curative therapy for selected groups of patients (pts). However, current ablation protocols are not standardized and predictors of CA success and sinus rhythm maintenance are not clearly defined. To evaluate whether left atrium (LA) volume quantification provided by multi-detector computed tomography (MDCT) might predict the success of pulmonary vein (PV) isolation procedure.


RESULTS
We evaluated 99 pts, 66 male, mean age 54.4 +/- 10.1 years, referred for CA because of drug resistant AF. All pts were submitted to 64-slice MDCT scan for electroanatomic mapping integration, pulmonary veins anatomy delineation, LA thrombi exclusion, and LA volume estimation. Complete isolation of all the PVs was always performed with eventual cavo-tricuspid isthmus ablation. For a mean follow-up period (Fup) of 16.7 +/- 6.6 months, clinical success was assessed after a 3-month blanking period. Anti-arrhythmic drug therapy was discontinued or modified at the clinician's criteria. At the end of the Fup, 29 pts suspended anti-arrhythmic drug therapy and 26% were of oral anticoagulation. Univariate analysis showed that the probability of AF relapse after CA was higher in pts with non-paroxysmal forms of AF. The probability of relapse was significantly higher in pts with LA volumes greater than 100 mL when assessed by MDCT. We found that the LA volume of 145 mL was a good cut-off value for AF recurrence prediction. Patients with LA volumes greater than 145 mL had significantly higher recurrence rates of arrhythmia, even when adjusted for the effect of age, gender, body mass index, hypertension, and type of AF.


CONCLUSIONS
Left atrium volume estimated by MDCT may be useful to identify pts in whom successful AF ablation can be achieved with simpler ablation procedures, restricted to PV isolation.
Abecasis
João
J
Cardiologia, Centro Hospitalar de Lisboa Ocidental, Rua Professor Reynaldo dos Santos 2795-523 Carnaxide, Portugal.
Dourado
Raquel
R
Ferreira
António
A
Saraiva
Carla
C
Cavaco
Diogo
D
Santos
Katya Reis
KR
Morgado
Francisco Belo
FB
Adragão
Pedro
P
Silva
Aniceto
A
D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006329:Heart Conduction System / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D017063:Outcome Assessment, Health Care / Q000379:methods; D011379:Prognosis; D011667:Pulmonary Veins / Q000000981:diagnostic imaging* / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome