Predictive Value of Left Atrial Volume Measured by Multi-Detector Computed Tomography or Cardiac Magnetic Resonance Imaging In the Treatment of Paroxysmal Atrial Fibrillation

Background:

We investigate the role of left atrial volume (LAV), measured by MDCT or cardiac MRI, as a predictor of outcome following pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (AF).

Methods:

PVI was performed in 213 patients (80 females, age 60±10 years) with paroxysmal AF. LAV was assessed by MDCT (n=39) or cardiac MRI (n=174) prior to ablation. LA-diameter (LAD) and LA-area were determined by echocardiography.

Results:

The mean LAV was 85±28ml (range 22–189ml). The mean LAD and the mean LA-area were 42±6mm and 23±6cm². After a follow-up period of 18±5 months AF-recurrence was documented in 50 (23%) patients. Univariate analysis showed age (59±11 vs. 65±6 years, p:0.003), LA-area (22±5 vs. 27±6cm², p:0.02) and LAV (80±27 vs. 96±28ml, p:0.03) to be significantly associated with outcome. However, multivariate analysis revealed that none of these parameters were significant (odds ratio LAV:0.55–1.08; p:0.056, LA-area:0.67–1.10; p:0.063 and age:0.79–1.06; p:0.4). In case of AF recurrence, patients with LAV >95ml showed a significant higher probability for the occurrence of persistent AF (42% vs. 6%, p:0.003).

Conclusion:

The ablation success following PVI in patients with paroxysmal AF is independent of pre-ablation LAV. However, pre-ablation LAV >95ml is associated with the occurrence of persistent AF in case of AF recurrence following PVI.

Key words:

Atrial fibrillation – left atrial volume – ablation success – cardiac magnetic resonance imaging – multidetector computed tomography