Impact of increased orifice size and decreased flow velocity of left atrial appendage on stroke in nonvalvular atrial fibrillation.
The structural and functional characteristics of left atrial appendage (LAA) in patients with atrial fibrillation (AF) with previous stroke remain incompletely elucidated. This study investigated whether a larger LAA orifice is related to decreased LAA flow velocity and stroke in nonvalvular AF. The dimension, morphology, and flow velocity of LAA were compared in patients with nonvalvular AF with (stroke group, n = 67, mean age 66 ± 9 years) and without ischemic stroke (no-stroke group, n = 151, mean age 56 ± 10 years). Compared with no-stroke group, the stroke group had larger LA dimension (4.7 ± 0.8 vs 4.2 ± 0.6 cm, p <0.001), larger LAA orifice area (4.5 ± 1.5 vs 3.0 ± 1.1 cm(2), p <0.001), and slower LAA flow velocity (36 ± 19 vs 55 ± 20 cm/s, p <0.001). LAA flow velocity was negatively correlated with LAA orifice size (R = -0.48, p <0.001). After adjustment for multiple potential confounding factors including CHA2DS2-VASc score, persistent AF, and LA dimension, large LAA orifice area (odds ratio 6.16, 95% confidence interval 2.67 to 14.18, p <0.001) and slow LAA velocity (odds ratio 3.59, 95% confidence interval 1.42 to 9.08, p = 0.007) were found to be significant risk factors of stroke. In patients with LAA flow velocity <37.0 cm/s, patients with large LAA orifice (>3.5 cm(2)) had greater incidence of stroke than those with LAA orifice of ≤3.5 cm(2) (75% vs 23%, p <0.001). In conclusion, LAA orifice enlargement was related to stroke risk in patients with nonvalvular AF even after adjustment for other risk factors, and it could be the cause of decreased flow velocity in LAA.
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Jung Myung
JM
Lee
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Jaemin
J
Shim
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Jae-Sun
JS
Uhm
Department of Radiology, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Young Jin
YJ
Kim
Department of Radiology, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Hye-Jeong
HJ
Lee
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Hui-Nam
HN
Pak
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea.
Moon-Hyoung
MH
Lee
Division of Cardiology, Department of Internal Medicine, Research Institute of Radiological Science, Yonsei University Medical College, Seoul, Korea. Electronic address: cby6908@yuhs.ac.
Boyoung
B
Joung
D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D016280:Atrial Function, Right / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D002545:Brain Ischemia / Q000453:epidemiology / Q000209:etiology*; D016001:Confidence Intervals; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors