Correspondence on "Beta-blockers and renin-angiotensin system inhibitors for Takotsubo syndrome recurrence: a network meta-analysis" by Santoro et al

Santoro et al,1 in their carefully designed and implemented meta-analysis, have concluded that beta-blockers (BB) and renin-angiotensin system inhibitors (RASI), administered after an index episode of Takotsubo syndrome (TTS), are not protective of recurrence. Scrutiny of the € limitations' section of their paper reveals that there are many drawbacks in implementing meta-analyses of existing data from the literature, suggesting that we should resort to large multicentre registries and randomised controlled trials to resolve the conundrum whether such therapy(ies) could prevent TTS recurrence. This author believes that exploration of whether BB and/or RASI could exert a preventive effect for TTS recurrence is not feasible, and here is why: (1) patients with TTS are admitted to the hospital with considerable delays, thought usually to have suffered an acute coronary syndrome, or some other serious cardiology pathology, and have already been started on BB and/or RASI; before TTS is first suspected or eventually confirmed; (2) patients with TTS are not immune to comorbidities, compared with the general population, for which BB and/or RASI are indicated; (3) many such patients with TTS are already on BB and/or RASI prior to their index admission to the hospital with TTS; (4) patients with TTS are discharged on BB and/or RASI, drugs which have been administered for symptoms/complications, experienced during hospitalisation; (5) patients with TTS experience varying types and severity of comorbidities for varying time intervals, for which BB and/or RASI are indicated; (6) there is a need of increasing/decreasing the dose, or temporary/permanent discontinuation of BB and/or RASI, in response to clinical perturbation, at follow-up of patients with an index episode of TTS; (7) there is variation in the type and dose, as well as duration of BB and/or RASI, prescribed by different physicians, caring for patients with a previous index episode of TTS; (8) there is variation in the drug therapy compliance of patients with a previous index episode of TTS; (9) there are enormous difficulties in recruiting patients with an index episode of TTS in potential future randomised controlled trials considering the above. Perhaps, only very large multicentre registries may provide the only solution for evaluation whether BB and/or RASI are protective for a TTS recurrence at long-term follow-up provided they include patient € granular' data, for the patients' entry/acceptance to the registries, with the provision that such data will continue to be entered at long-term follow-up in the patients' data electronic files.