Left ventricular outflow tract obstruction and myocardial edema burden in Takotsubo syndrome: acute and long-term outcomes-insights from the EVOLUTION registry.

OBJECTIVE: To evaluate the clinical and CMR characteristics and the in-hospital and long-term outcomes of patients with Takotsubo syndrome (TTS) and left ventricular outflow tract obstruction (LVOTO). MATERIAL AND METHOD: This sub-analysis of the multicenter retrospective EVOLUTION registry included patients with TTS enrolled between November 21, 2007, and December 22, 2024, who underwent CMR within 5 days of echocardiographic assessment. Patients were stratified according to the presence or absence of LVOTO. RESULTS: A total of 249 patients were included (226 women [90.8%]; mean age 70.6 ± 10.9 years), of whom 26 (10.4%) had LVOTO. Patients with LVOTO exhibited higher left ventricular mass, greater basal septal wall thickness, and more extensive T2-STIR involvement. Among CMR parameters, the number of T2-STIR-positive segments was independently associated with the presence of LVOTO (OR = 1.38, 95% CI: 1.17-1.63, p = 0.001). In-hospital complications, including pulmonary edema and cardiogenic shock, were more frequent among patients with LVOTO (34.6% vs. 15.8%; p = 0.018), and LVOTO remained independently associated with in-hospital complications on exploratory multivariable analysis (OR = 3.16, 95% CI: 1.08-9.26, p = 0.035). No significant association was observed between LVOTO and long-term MACE (HR 1.523, 95% CI 0.641-3.620; p = 0.340). CONCLUSION: LVOTO in patients with TTS, is independently associated with the extent of myocardial edema, and is more frequently observed in patients who experience in-hospital complications. No significant association with long-term MACE was found, though the limited number of events and wide confidence interval warrant cautious interpretation.