Fibrotic atrial cardiomyopathy (FACM) is associated with new-onset atrial fibrillation (AF), higher arrhythmia recurrence rates after pulmonary vein isolation (PVI) and an increased risk for stroke. Therefore, the current ESC guidelines on AF underline the importance of FACM diagnosis. At present, FACM diagnosis is feasible by invasive endocardial contact mapping of left atrial (LA) low-voltage substrate (LVS) or late gadolinium-enhanced magnetic resonance imaging, which are both limited in widespread use due to their complexity.
Objectives:

The aim of the current study was to assess the feasibility of echocardiography for diagnosis of FACM and outcome prediction after PVI.

Methods:

Thirty-nine consecutive patients (age 66±9 years, 82% male) undergoing their first PVI procedure for persistent AF were studied. Transthoracic echocardiography and high-density LA voltage maps (>2000 sites) were acquired in sinus rhythm prior to PVI. Arrhythmia recurrence was assessed using 72-hour Holter ECG six and 12 months after PVI.

Results:

The echocardiographic parameters LA ejection fraction (LA-EF) and LA strain (reservoir, conduit and contraction strain) were significantly correlated with invasive LA-LVS extent (p<0.05). FACM (prespecified as LA-LVS extent ≥2 cm² at 0.5 mV threshold) was present in 22 (56%) patients and could be diagnosed by LA-EF and LA strain parameters. LA-EF and reservoir strain predicted FACM most accurately (area under the curve of 0.896 and 0.870, respectively) with a sensitivity of 94.1% and 82.4% and a specificity of 72.7% and 86.4%, respectively. Freedom from arrhythmia recurrence after PVI was significantly higher in patients with a LA-EF ≥32% or a contraction strain ≥5.6% compared to patients with reduced values (77.3% vs. 41.2% and 78.3% vs. 37.5%, p<0.02 respectively).

Conclusions:

The echocardiographic parameters LA-EF and LA strain allowed accurate diagnosis of FACM. Furthermore, LA-EF and LA contraction strain predicted arrhythmia recurrence after PVI emphasizing the clinical value of these non-invasive parameters.