Nearly all left atrial thrombi may be extended from pulmonary vein thrombi

Keywords

Pulmonary vein thrombus;64-MDCT;Left atrial thrombus;Stroke

Ischemic stroke is a serious clinical problem [1] ;  [2]. To prevent ischemic stroke, it is crucial to identify clinical targets. Left atrial thrombus is a known cause of ischemic stroke [2] ;  [3]; however, the cause of left atrial thrombus remains unknown.

Pulmonary vein thrombosis (PVT) is thought to be rare; however, I have published several cases of PVT in elderly patients with chest pain using a 64-slice multidetector CT (64-MDCT) since 2012 [4]; [5]; [6]; [7]; [8]; [9] ;  [10]. In 2014, I reported that 61% (35 patients) of 57 elderly patients with chest pain had PVT, as assessed using 64-MDCT, which suggests that PVT is common in elderly patients with chest pain [9]. Although I have reported that a thrombus in the pulmonary vein extends into the left atrium [5]; [6]; [8] ;  [9], the relationship between PVT and a left atrial thrombus remains unknown.

I reviewed the images of 64-MDCT scans obtained from 35 patients with PVT. Seventeen patients (49%) had a thrombus in the left atrium, which was extended from pulmonary vein thrombi, indicating that approximately half of patients with PVT had a left atrial thrombus. In addition, among the 22 patients without PVT, only three patients (14%) had a left atrial thrombus. These three patients may have a fine pulmonary vein thrombus, which could not be clearly visualized using 64-MDCT. Thus, there is a possibility that nearly all left atrial thrombi are extended from pulmonary vein thrombi. Nearly all left atrial thrombi may use pulmonary vein thrombi as a root, which may provide a strong structure in the thrombi. In addition, I reported that some of the thrombi were partially dissolved within three months following warfarin [4] and dabigatran [7]; [8] ;  [9] treatment, indicating that warfarin and dabigatran could prevent ischemic stroke by dissolving the pulmonary vein thrombus and the connected left atrial thrombus. However, not all thrombi were dissolved upon warfarin [5] and dabigatran [10] treatment, and thus, more efficient anti-coagulants are needed to prevent ischemic stroke.

Conflict of interest

The authors report no relationships that could be construed as a conflict of interest.

References

1. [1] K. Strong, C. Mathers, R. Bonita; Preventing stroke: saving lives around the world; Lancet Neurol, 6 (2007), pp. 182–188
2. [2] P.A. Wolf, R.D. Abbott, W.B. Kannel; Atrial fibrillation as an independent risk factor for stroke: the Framingham Study; Stroke, 22 (1991), pp. 983–988
3. [3] J.L. Blackshear, J.A. Odell; Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation; Ann Thorac Surg, 61 (1996), pp. 755–759
4. [4] H. Takeuchi; A thrombus of the right upper pulmonary vein: detection by the use of a 64-MDCT; BMJ Case Rep (Sep 14 2012) https://doi.org/10.1136/bcr.12.2011.5446 [Published online:]
5. [5] H. Takeuchi; 64-MDCT scan demonstrated pulmonary vein thrombus; J Neurol Neurophysiol, S8 (2013), p. 002 https://doi.org/10.4172/2155-9562.S8-002
6. [6] H. Takeuchi; 64-MDCT can depict the thrombi expanded from the left lower pulmonary vein to the left atrium in the patient with angina pectoris; BMJ Case Rep (Apr 3 2013) https://doi.org/10.1136/bcr.2013-008750 [Published online:]
7. [7] H. Takeuchi; Floating thrombus in the left upper pulmonary vein dissolved by dabigatran; BMJ Case Rep (Oct 9 2013) https://doi.org/10.1136/bcr-2013-200836 [Published online:]
8. [8] H. Takeuchi; Chest pain caused by pulmonary vein thrombi could be curable by dabigatran; BMJ Case Rep (March 13 2014) https://doi.org/10.1126/bcr-2013-203186 [Published online:]
9. [9] H. Takeuchi; High prevalence of pulmonary vein thrombi in elderly patients with chest pain, which has relationships with aging associated diseases; IJC Heart Vessels, 4 (2014), pp. 129–134 https://doi.org/10.1016/j.ijchv.2014.05.006 [Published online: 6-JUN-2014]
10. [10] H. Takeuchi; Pulmonary vein thrombi in a patient with paroxysmal atrial fibrillation; IJC Heart Vasculature, 5 (2014), pp. 63–64 https://doi.org/10.1016/j.ijcha.2014.10.006