Background: The risk of developing a stroke or systemic embolus due to a left atrial (LA) thrombus in patients with atrial fibrillation (AF) and/or atrial flutter (AFL) is estimated by the CHADS(2) score and more recently the CHA(2)DS(2)-VASc score. We aimed to further characterize AF/AFL patients who were found to have a LA thrombus on a transesophageal echocardiogram (TEE).
Methods and results: Of 3,165 TEE between 2005 and 2011 for a broad spectrum of indications, we detected 65 AF patients with LA thrombus (2 %). There were 40 men and 25 women, mean age was 65 ± 13 years (range 36-88 years). Mean CHADS(2) score was 1.8 ± 1.1 and mean CHA(2)DS(2)-VASc score was 3.0 ± 1.6. 11 patients (17 %) had a CHADS(2) score of 0, 12 patients (18 %) of 1, 28 patients (43 %) of 2 and 12 patients (18 %) of 3. Hypertension was the most frequent risk factor (72 %), followed by congestive heart failure (32 %), diabetes (23 %) and age ≥75 years (23 %). Mean difference between CHADS(2) and CHA(2)DS(2)-VASc was 1.25 ± 0.91. Of the 11 patients (17 %) with a LA thrombus despite a CHADS(2) score of 0, five had a CHA(2)DS(2)-VASc score of 0, four a CHA(2)DS(2)-VASc score of 1 and two a CHA(2)DS(2)-VASc score of 2.
Conclusion: In an unselected TEE population with newly detected LA thrombus about one-third of patients fell into the low-risk group when classified based on the CHADS(2) score, while a much lower population fell in the same low-risk group when classified according to the CHA(2)DS(2)-VASc score. However, this does not prove clinical superiority of the CHA(2)DS(2)-VASc score over the established CHADS(2) score. Whether our observation has clinical implications (e.g. TEE prior to LA ablation irrespective of CHADS(2) score), or argues for use of the CHA(2)DS(2)-VASc score needs to be evaluated in prospective studies.