Occult paroxysmal atrial fibrillation (PAF) may cause a significant part of ischemic strokes (IS) or transient ischemic attacks (TIA) remaining unexplained in 20 to 40% after standard care. Thus, invasive monitoring for PAF screening is recommended but remains silent in more than 80% of patients after 6 months. Also, non invasive transthoracic echocardiography (TTE) can help to predict PAF by assessing of atrial volumes and diastolic function. However, diastolic function classification requires a complex approach.

Transmitral E/A ratio drives a significant part of diastolic function evaluation. It is also influenced by atrial systolic function, often impaired in between PAF periods. We hypothesized that E/A increases in the acute phase of IS or TIA related to occult PAF, independently of traditional variables associated with PAF such as age and left atrial volume (LAv).

A retrospective cohort of IS or TIA patients were included. TTE was performed in sinus rhythm within 30 days after IS or TIA. We excluded LVEF<50%, significant valvular disease and pace-maker. PAF diagnosis was made by 72-hours monitoring or if reported within 6 months follow-up. Clinical and TTE variables were compared between PAF and non-PAF patients.

Between Jan 2015 and Apr 2017, 682 patients were included (101 PAF and 581 non-PAF). Main characteristics are shown in Table 1. In multivariable logistic regression, only age, LAv, A/E and LVmass were predictive of PAF. ROC curves for prediction of PAF were significantly better when integrating successively, LAv (AUC 0.75) over age alone (AUC 0.70), and E/A (AUC 0.79) over age+LAv (AUC 0.75); P<0.05) (Fig. 1).

The simple and accessible E/A ratio is an independent predictor of occult PAF in the acute phase of ischemic stroke and may help to stratify patients for invasive monitoring.