Dobutamine-assisted exclusion of left atrial appendage thrombus in atrial fibrillation patients with sludge.

BACKGROUND

Dense spontaneous echo contrast (SEC) and sludge in the left atrial appendage (LAA) complicate differentiation between sludge and thrombi during transoesophageal echocardiography (TOE). We prospectively evaluated the feasibility, safety, and efficacy of dobutamine to reduce sludge and improve thrombus detection in patients with atrial fibrillation (AF).

METHODS AND

RESULTS

This was an open-label, single-arm, single-center clinical study. A total of 20 patients with LAA sludge on TOE received intravenous dobutamine infusion, starting at 5 μg/kg/min and increasing to 10 and 20 μg/kg/min at 3-min intervals until sludge resolution. SEC grade and thrombus presence were reassessed at the maximum dose. All patients had LAA sludge at baseline, which improved to SEC grade 2 in 5% of patients, grade 1 in 75%, and completely resolved in 20%. Peak dobutamine doses were 5 μg/kg/min in one patient, 10 μg/kg/min in six patients, and 20 μg/kg/min in 13 patients. Dobutamine significantly increased LAA emptying velocity (median: 13.8 to 18.7 cm/s, P < 0.001), emptying fraction (12.8% to 28.9%, P < 0.001), medial and lateral LAA wall velocities (6.6 to 8.4 cm/s, P = 0.012; 5.8 to 7.3 cm/s, P = 0.007, respectively), and left ventricular (LV) ejection fraction (51.8% to 60.0%, P < 0.001). Median heart rate increased from 78 to 89 bpm, while median systolic blood pressure briefly dropped from 116 to 105 mmHg before recovering to 123 mmHg three minutes post-infusion. No severe adverse events or hemodynamic instability occurred.

CONCLUSION

By enhancing LAA and LV function, dobutamine infusion during TOE reduces sludge and facilitates LAA thrombus exclusion in patients with AF.