LAUSR

BACKGROUND Although complex aortic plaque (CxAoP) is a component of the CHA2DS2-VASc score in patients with atrial fibrillation (AF), it is underestimated without detection by trans-esophageal echocardiogram (TEE). We have evaluated the incidence and significance of CxAoP among patients with non-valvular AF (NVAF). METHODS We included 981 patients with NVAF who underwent catheter ablation (59.1±11.1years old, 73.7% male, 70.2% paroxysmal AF). All of the patients underwent pre-procedural TEE evaluation. Left atrial (LA)-cardioembolic (CE) milieu was defined as a dense spontaneous echo-contrast or LA appendage flow velocity≤20cm/s. RESULTS CxAoP was present in 8.3% of patients, and independently associated with age (OR 1.07, 95% CI 1.03-1.10, p<0.001), male sex (OR 2.34, 95% CI 1.29-4.24, p=0.005), and CHA2DS2-VASc score≥2 (OR 3.33, 95%CI 1.42-7.77, p=0.005). The presence of LA-CE milieu overlapped with CxAoP in only 11% of patients. Patients with CxAoP had a higher prevalence of hypertension (p=0.004), smoking history (p=0.008), paroxysmal AF (PAF, p<0.001), and a smaller LA volume index (p<0.001) than those with LA-CE milieu. The prevalence of persistent AF among patients with a history of stroke was significantly lower in the presence of CxAoP than in those with LA-CE milieu (p=0.014). CHA2DS2-VASc score was underestimated in 11% of high-risk patients (CHA2DS2-VASc score≥2) due to undetected CxAoP. CONCLUSIONS CxAoP may contribute to the risk of stroke by a different mechanism than LA-CE milieu in patients with NVAF. Imaging assessment for CxAoP affects thromboembolic risk stratification and decision making for stroke prevention in patients with NVAF.