The importance of transesophageal echocardiography in stroke - results of a large single-center cross-sectional study

Strokes are one of the leading causes of death worldwide. Despite intensified diagnostics, the majority of strokes must be classified as cryptogenic. In this context the role of a PFO with or without ASA seems unclear and is controversial in the literature. Furthermore there are morphological changes in the left atrium with changes in the flow velocities suspected of having a role to play in the pathogenesis of cryptogenic stroke. In this context, we retrospectively examined 909 patients (354 women, 555 men, median age 63 years), who were, at the University Medicine of Göttingen from 2012 to 2014 because of a stroke or a TIA, examined and treated echocardiographically and cardiologically. The main risk factors in these patients were arterial hypertension (65.7%), hyper- / dyslipidemia (32.5%), nicotine abuse (26.5%) and diabetes mellitus (20.4%). According to the TOAST classification, 7.3% of the strokes were classified as macroangiopathic, 16.6% as microangiopathic, 21.6% as cardioembolic, 47.7% as cryptogenic and 4.3% classified as “other causes”. With the help of regression analyzes, we have determined influencing factors that had effects on the severity of the stroke as measured by the NIHSS. In this context the multivariate analysis showed a significantly higher NIHSS for admission and discharge in patients with a reduced flow velocity in the left atrial appendage of less than 60 cm / s. In addition, the NIHSS was comparable to the stroke severity of patients with atrial fibrillation. An abrupt rise in the NIHSS, in the sense of a threshold phenomenon, was evident from a flow velocity of less than 63 cm / s. When patients with atrial fibrillation and heart failure were excluded from this analysis to rule out a mutual influence, this threshold phenomenon continued and started at a speed of less than 45 cm / s. Additionally a significant inverse correlation between atrial size and flow velocity could be found. It is therefore an independent risk factor for the development of a severe stroke. Another central part of this work was the analysis of patients who had a PFO (26.2%). Here it was shown that cryptogenic strokes in the patient group with PFO occurred significantly more frequently than in the comparison group without PFO (p = 0.003). Patients with PFO had fewer previous cardiovascular diseases and a significantly lower NIHSS at admission and discharge compared to patients without PFO. When patients with TIA were excluded, which was relatively more common in patients with PFO, results still showed a lower stroke severity as measured by the NIHSS in this patient subgroup. In summary, we come to the conclusion that a PFO is important for the development of a stroke, however, more of a multifactorial event. Because of that especially in patients with cryptogenic stroke and lack of cardiovascular risk factors intensive diagnostics should be initiated to detect appropriate changes hearts echocardiographically. In further prospective studies another focus should be placed on the reduced flow velocity in the LAA, as this goes hand in hand with a significantly more severe stroke as measured by the NIHSS. It seems important to evaluate these results in the context of prospective analyzes and, depending on the results, to consider oral anticoagulative therapy in terms of primary and secondary prophylaxis.2021-03-0