Prognostic impact of initial left ventricular dysfunction in takotsubo syndrome: comparative analysis according to LVEF at admission

Abstract Introduction Takotsubo Syndrome (TTS), also known as stress-induced cardiomyopathy, is an acute and typically reversible myocardial disorder that mimics acute coronary syndrome both clinically and electrocardiographically. It is characterized by transient regional systolic dysfunction of the left ventricle, often triggered by intense emotional or physical stress. Despite its transient nature, the acute phase may carry significant morbidity and mortality, comparable to that of acute coronary events. Left ventricular ejection fraction (LVEF) is widely used as a marker of systolic function and disease severity at admission, although the prognostic value of a reduced left ventricular ejection fraction (LVEF) at admission in these patients is not fully established. Objective The objective of this study was to compare clinical characteristics, treatment, and in-hospital outcomes of patients with TTS according to LVEF at admission (40% vs ≥40%), aiming to clarify its prognostic significance in the acute setting. Methods We conducted a retrospective observational study including 100 patients with TTS admitted to a cardiac intensive care unit (CICU) between 2012 and 2024. Patients were divided into two groups based on LVEF at admission: LVEF 40% (n = 52) and LVEF ≥40% (n = 48). Clinical, analytical, hemodynamic, therapeutic, and outcome variables were analyzed. Student’s t-test and chi-square tests were applied. Results Mean age was similar between both groups (70.73 ± 9.29 vs 68.4 ± 10.20 years). Female sex was predominant in both (82.7% vs 85.4%). There were no significant differences in baseline characteristics (Table 1), except for dyslipidemia, which was more frequent in the LVEF 40% group (53.8% vs 35.4%, p = 0.009). This group also presented higher creatinine (1.06 ± 0.58 vs 0.84 ± 0.28 mg/dL; p = 0.0005) and high-sensitivity troponine levels (762.7 ± 725.8 vs 524.5 ± 371.3 ng/L; p = 0.0148) at admission. Nineteen percent were admitted in cardiogenic shock. Use of inotropic and vasopressor support was higher in this group: dobutamine (21.2% vs 0%; p 0.0001) and norepinephrine (19.2% vs 2.1%; p = 0.0035). There were no significant differences in LVEF at discharge (~61%) or in-hospital mortality between groups. Conclusions An LVEF 40% at admission in patients with Takotsubo Syndrome is associated with greater initial clinical severity and more frequent need for inotropic and vasopressor support. However, this does not translate into poorer recovery of LVEF or higher in-hospital mortality. Our findings support the role of LVEF as a marker of acute severity but not as a predictor of mid-term outcomes, underscoring the need to incorporate complementary risk-stratification tools such as global longitudinal strain or cardiac magnetic resonance imaging, and to ensure close clinical follow-up after the acute event.