Takotsubo syndrome (TTS) is a poorly recognized heart disease that was initially regarded as a benign condition. Recently, it has been shown that TTS may be associated with severe clinical complications including death and that its prevalence is probably underestimated. Since current guidelines on TTS are lacking, it appears timely and important to provide an expert consensus statement on TTS. The clinical expert consensus document part I summarizes the current state of knowledge on clinical presentation and characteristics of TTS and agrees on controversies surrounding TTS such as nomenclature, different TTS types, role of coronary artery disease, and etiology. This consensus also proposes new diagnostic criteria based on current knowledge to improve diagnostic accuracy.

The clinical expert consensus statement on takotsubo syndrome (TTS) part II focuses on the diagnostic workup, outcome, and management. The recommendations are based on interpretation of the limited clinical trial data currently available and experience of international TTS experts. It summarizes the diagnostic approach, which may facilitate correct and timely diagnosis. Furthermore, the document covers areas where controversies still exist in risk stratification and management of TTS. Based on available data the document provides recommendations on optimal care of such patients for practising physicians.

The clinical course of takotsubo syndrome (TTS) can be complicated by several life-threatening conditions. In particular, cardiogenic shock (CS) represents one of the leading causes of mortality in the acute phase and occurs in a considerable number of patients with TTS, with an incidence of ≈10%. At present, no established guidelines are available to support specific treatment recommendations,and the conventional therapy for CS leads to uncertain results in TTS cases. The International Takotsubo Registry (www.takotsubo-registry.com) is an observational, prospective, and retrospective registry established at the University Hospital Zurich in 2011, with the largest TTS database worldwide. Patients were included in the registry between 2011 and 2017 based on modified Mayo Clinic Diagnostic criteria. Hospitalization data were recorded through standardized forms on admission or during revision of clinical charts; follow-up data were obtained from medical records, telephone follow-up, or clinical visits. The study population was categorized into 2 groups: patients with TTS with and without CS. The study protocol was reviewed by the respective local ethics committees or investigational review boards at each collaboration site. Where informed consent was required, formal written consent was obtained from patients.