Malignancy predicts outcome of Takotsubo syndrome: a systematic review and meta-analysis

Over the recent years, studies have emerged reporting on a strong relationship between the occurrence of malignancy and Takotsubo syndrome. The aim of this systematic review and meta-analysis is to evaluate the predictive value of malignancy for prognosis of Takotsubo syndrome patients. PubMed, EMBASE, Cochrane Library, Web of science, and Scopus were searched until 4 September 2019 for articles concerning association of malignancy with the prognosis of Takotsubo syndrome. A total of ten studies were finally included in this meta-analysis, demonstrating that malignancy was associated with higher mortality in Takotsubo syndrome patients (RR 2.23, 95% CI 1.64–3.03, Z = 5.10, P < 0.00001). Differences between individual studies were significant, which were due to sample size and percentage of malignant patients in each study indicated by meta-regression and then verified by sensitivity analysis. Subgroup analysis demonstrated that the predictive value of malignancy in mortality risk of Takotsubo syndrome patients was significant for both in-hospital death (RR 2.26, 95% CI 1.34–3.82, Z = 3.06, P = 0.002) and follow-up death (RR 2.04, 95% CI 1.63–2.55, Z = 6.21, P < 0.00001). Further analysis of other in-hospital outcomes demonstrated increased incidence of mechanical ventilation in cancer patients. Our meta-analysis suggested that malignancy plays a significant role in predicting the mortality of Takotsubo syndrome patients whether in the short term or long term.