Evaluation of microvascular dysfunction in patients with Takotsubo syndrome

Background:
Takotsubo syndrome (TS) is a transient cardiac syndrome often related to physical or emotional stress.

Methods:
A total of 134 patients admitted to the Cardiology Unit of the University Hospital Paolo Giaccone for suspected acute coronary syndrome were retrospectively enrolled in this study. A total of 67 patients with TS and 67 patients with Anterior STEMI matched to the TS patients for age and LVEF were selected.

Results
We enrolled 67 consecutive patients with TS, 64 women (95,52%) and 3 men (4,48%), from 2008 to 2017. Moreover a total of 67 patients with anterior STEMI, homogeneous for age, left ventricular ejection fraction and for main cardiovascular risk factors, compared to TS group (Table 1) was selected as control group. The control group was further divided into two subgroups based on the evidence of myocardial reperfusion: a subgroup consisting of 35 patients with anterior STEMI with effective reperfusion, and a subgroup consisting of 32 patients with anterior STEMI with microvascular obstruction. (Figure 1). Compared to patients with microvascular obstruction similar results were found (cTFC IVA 35.77 +/- 8.32 vs 33.92 +/- 8.47; p = 0.58; Figure 1). Moreover, in patients with TS, the QuBE score, expression of the perfusion of the myocardium in the apical region of the left ventricle, was significantly lower than in patients with STEMI and reperfusion evidence (8.60 +/- 3.03 vs 11.36 +/- 2.59; p = 0.008; Figure 2) and significantly higher than the group of STEMI with microvascular obstruction (8.60 +/- 3.03 vs 5.12 +/- 1.89; p = 0.00046).

Conclusions
In conclusion, our study indicates that in patients with Takotsubo syndrome the epicardial coronary flow and myocardial perfusion, in the territory involved by the typical kinesis anomalies of the left ventricle, are compromised, and therefore support the hypothesis that the dysfunction of the microcirculation constitutes one of the pathophysiological mechanisms underlying the disease. The alteration of myocardial perfusion is likely to be of intermediate grade in patients with Takotsubo, being worse than STEMI with successful reperfusion and better than that of non-reperfused STEMIs.