Correspondence on 'Outcomes of catecholamine and/or mechanical support in Takotsubo syndrome' by Terasaki et al

To the Editor: I enjoyed reading the report by Terasaki et al, about the 6169 patients with takotsubo syndrome (TTS) from the nationwide Japanese registry (JROADDPC) of all cardiac and vascular diseases, representing claims data of 4 years of registered patients, commenting on the particulars of patients with severe TTS (18.6%), who by definition necessitated catecholamines and/or mechanical support and patients with mild TTS, and the factors associated with complications and mortality. The authors found that the patients with severe TTS were more often male and had higher 30day inhospital mortality, Charlson scores, comorbid pneumonia, sepsis and higher ambulance use than patients with mild TTS, while mortality was increased with age. It has been previously theorised that the prevalence of diabetes mellitus (DM) may be lower in patients with TTS than in the general population, although others disagree with this notion. The implicit significance of this is that DM may exert a ‘protective effect’ towards the emergence of TTS, and in addition an ameliorating influence during hospitalisation (ie, ‘diabetes paradox’). 6 The overall prevalence of DM in the present study of patients with TTS was 14.1%, and DM was not a predictor of the severity of TTS in the univariate analysis (p=0.53), or 30day inhospital mortality (p=0.96). Since the study is based on a sizeable registry of >6000 patients, and is representative of the entire nation of Japan, it provides an opportunity to compare the prevalence of DM in patients with TTS (ie, 14.1%) with the prevalence of DM in the general Japanese population, particularly for women in their 60s and 70s, and the prevalence of DM in patients, again particularly for women in their 60s and 70s, admitted with other cardiac and vascular pathologies captured by the nationwide Japanese registry (JROADDPC). Indeed, it would be contributory to compare in parallel the corresponding DM prevalence of hypertension in the present study (42%) with the prevalence of hypertension in the general Japanese population, and in the patients admitted with other cardiac and vascular pathologies in the JROADDPC, particularly for women in their 60s and 70s, since hypertension is considered to be as frequent in patients with TTS, as in the general population, or in patients with other cardiac and vascular pathologies.