Page 17 - Journal of Structural Heart Disease Volume 5, Issue 5

Original Scientific Article 210 Table 3. Total numbers of other embolic sources in addition to patent foramen ovale or combined patent foramen ovale and atrial
septal aneurysm
Total numbers of other
embolic sources in addition to PFO or combined PFO and ASA
0(%) 26(44.8) 1(%) 19(32.8) 2(%) 12(20.7) 3(%) 1(1.7)
PFO: patent foramen ovale; ASA: atrial septal aneurysm.
Discussion
TEE is superior to transthoracic echocardiography for identifying intracardiac abnormalities [4]. It is es- pecially useful for identifying abnormal structures in detail, such as PFO and ASA, or other intracardiac embolic sources, such as LAAF, Chiari networks, and aortic valve calcification. A previous study has already shown the association between the presence of PFO and cryptogenic stroke in both older and younger pa- tients [5]. However, it did not clearly evaluate other causes of ESUS except for PFO and ASA. Moreover, no other previous study has clearly assessed and classi- fied the distribution of causes according to the ESUS criteria [1]. The present study utilized TEE to identify other causes of ESUS according to the ESUS criteria.
The prevalence of PFO on echocardiographic and autopsy studies in the healthy adult population is approximately 20%–25% [6-8]. Furthermore, approx- imately 40%–60% of cases of stroke with paradoxical embolism in young people are associated with PFO [8, 9, 19]. Notably, our study showed a higher inci- dence of PFO in ESUS patients compared with previ- ous studies, which may be attributed to our definition of PFO, i.e., the presence of at least one microbubble in the left atrium within three cardiac cycles after opacification of the right atrium using agitated saline contrast microbubbles [9], regardless of the num- ber of microbubbles. In addition, a previous study showed a positive relationship between the size of the shunt and the risk of stroke [10]. Some authors have indicated that PFO size can be defined by the
12(80.0) 2(13.3) 1(6.7) 0(0)
0.017 14(32.6) -
17(39.5) - 11(25.6) - 1(2.3) -
All patients (n=58)
Younger (n=15)
Older (n=43)
P value
number of microbubbles, where 3–10 microbubbles is a small shunt, 1–30 is a moderate shunt, and >30 is a large shunt [11]. Other previous studies have iden- tified that the morphological or functional character- istics of PFO are associated with paradoxical embolic stroke [12, 13]. In our study, these elements of PFO were not evaluated; however, we evaluated the fre- quency of ASA and found that it was anatomically related to PFO. The coexistence of PFO and ASA is a stronger risk factor for stroke than either source by it- self [14]. Our study demonstrated that the frequency of PFO or combined PFO and ASA without other car- dioembolic sources was 80% and 32.6% in younger and older ESUS patients, respectively.
Three previous trials, the CLOSURE-1 trial (Evalua- tion of the STARFlex Septal Closure System in Patients with a Stroke and/or Transient ischemic Attack due to Presumed Paradoxical Embolism through a PFO) [15], the RESPECT trial (Randomized Evaluation of Recur- rent Stroke Comparing PFO Closure to Established Current Standard of Care Treatment) [16] and the PC trial (Randomized Clinical Trial Comparing the Effica- cy of Percutaneous Closure of Patent Foramen Ovale With Medical Treatment in Patients With Cryptogen- ic Embolism) [17] did not show a superiority for PFO closure over medical therapy in patients with cryp- togenic stroke. However, more recent trials showed that PFO closure is effective in preventing recurrent stroke [2, 3, 18]. These trials reported that the rates of recurrent stroke in younger (18–60 years) patients were significantly lower with closure of the PFO plus antiplatelet therapy than with antiplatelet therapy
Journal of Structural Heart Disease, October 2019
Volume 5, Issue 5:206-212