Does duration of atrial fibrillation symptoms reliably predict detection of left atrial thrombus in patients presenting for cardioversion

Backgrounds

Large retrospective, population-based trials argue for minimal thromboembolic

risk for cardioversion in patients with shorter than 48 hours atrial fibrillation

(AF) symptoms duration. Our goal was to compare the prevalence of left atrial

thrombi (LAT) as demonstrated by Trans Esophageal Echocardiography (TEE)

exam between patients undergoing cardioversion within the first 48 hours since

AF symptoms onset and later presenters.

Methods

We conducted a retrospective cohort study including consecutive patients

referred for cardioversion to Padeh Medical Center, not previously treated with

oral anticoagulation, between December 2015 and June 2019. All patients

underwent TEE to exclude LAT presence. Patients were divided into two

groups based on AF symptoms duration as recorded in medical records: 1) up to

48 hours, 2) longer than 48 hours. Clinical characteristics and prevalence of

LAT detection were compared. Patients with undetermined AF duration were

compared to patient with longer than 48 hours AF duration in a separate analysis.

Results

The study included 135 patients (73 females, age 66.46±10.78 years). The

“early presenters” were younger (63.11 vs. 68.75, p<0.001), with less co-

morbidities including hypertension (61.3% vs. 80%), Diabetis Mellitus (21% vs.

48.3%), Coronary artery disease (6.5% vs. 11.7%) and Heart Failure (17.7% vs.

28.3%) compared with “later presenters”.

LAT was detected in 13(21%) of 62 early presenters, compared to 20 (33%) of

60 patients with > 48 hours symptom duration (P=0.12). LAT was

detected among 2 of 14 (14.3%) patients with undetermined duration of

symptoms, not significantly different compared to patients with symptoms

longer than 2 days (P= 0.16).

Conclusions

The rate of LAT among patients presenting within 48 hours of AF symptoms

onset is relatively high. Duration of symptoms is not reliable for excluding LAT presence. Hence, safety of cardioversion without TEE in

patients presenting within 48 hours of AF symptoms onset should be revised.