Left atrial strain as an independent predictor of sinus rhythm maintenance after catheter ablation for paroxysmal atrial fibrillation in HFpEF patients

Type of funding sources: None.

The early AF treatment by radio-frequency catheter ablation is very important for improving clinical outcome in patients with history of atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). Left atrial (LA) strain showed to be a useful index to monitor atrial function in AF and HFpEF states. However, the accuracy of LA strain to predict the long-term maintenance of sinus rhythm (SR) in HFpEF patients with paroxysmal AF undergoing catheter ablation is still under debate.

To define the best echocardiography derived parameters to predict the long-term maintenance of SR in paroxysmal AF patients with high probability of HFpEF undergoing catheter ablation.

We prospectively enrolled (between September 2017 and May 2019) 200 consecutive patients (62 ± 10 years, 58% males) with dyspnea (NYHA≥II), paroxysmal AF and preserved LV ejection fraction (≥50%). All patients had a H2FPEF score suggesting high probability of HFpEF. During sinus rhythm, all patients underwent comprehensive transthoracic echocardiography at baseline, including assessment of left ventricular (LV) global longitudinal strain (GLS), left atrial (LA) reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct) using two-dimensional speckle tracking in apical views.

After 42+/-8 months follow-up, a total of 34 (17%) patients had a documented recurrence of AF. Patients with AF recurrence had lower LASr (22.2% vs. 28.3%, p < 0.001) and LASct (10.9% vs. 13.2%, p < 0.01) compared to patients who keep on SR. Among speckle tracking derived LA phasic strain indices, LASr showed the largest area under the curve (AUC = 0.8, p < 0.001) and the strongest independent predictive value (LASr > 22%) of long-term maintenance of SR with sensitivity of 80% and specificity of 66% (Figure 1). Other parameters of LA function, LA diameter, maximum or minimum LA volume index, LV GLS or ejection fraction, and indices of LV diastolic function had lower area under the curve. Using multivariable logistic regression, only LASr (OR 0.89, 95% CI 0.81-0.97, p=0.013) was independently associated with long-term SR maintenance while other LA size and function indices were not.

In HFpEF patients with paroxysmal AF undergoing catheter ablation, LASr is more accurate predictor of SR maintenance than other standard echocardiographic parameters in long-term follow-up.

Figure 1: Receiver-operating characteristic curves of left atrial reservoir strain (LASr), LA conduit strain (LAScd) and LA contractile strain (LASct), LA emptying fraction (LAEF), LA expansion index (LAEI), LA end-systolic (LAES) and end-diastolic (LAED) volume index (VI) to predict long-term maintenance of sinus rhythm.