Takotsubo Cardiomyopathy Outcomes Should Be Stratified Based on the Triggering Etiology

The study by Tornvall et al. (1) published in a recent issue of the Journal showed an increased mortality risk associated with Takotsubo cardiomyopathy (TC). After multivariate adjustment for coronary artery disease risk factors and risk markers for TC, the mortality rates were comparable among patients with TC and acute coronary syndrome (ACS). However, one of the major limitations was that the study failed to subdivide the patients of TC into its primary and secondary forms. Primary TC occurs in the setting of emotional or psychic stimuli or no identifiable triggers (idiopathic), whereas secondary TC is triggered by physical stressors such as sepsis, intracranial hemorrhage or cerebrovascular accident, trauma, surgery, or other critical illnesses (2). Secondary TC is associated with much worse short- and long-term prognoses (2). Primary TC, in comparison, generally has a benign spectrum and a good overall prognosis, unless complicated by cardiogenic shock. In a large recent study that used the RETAKO National Registry (Spanish REgistry for TAKOtsubo cardiomyopathy), the patients were divided into primary and secondary TC cohorts, who had otherwise similar demographic, functional, and cardiovascular risk profiles (2). Those with secondary TC had significantly increased mortality rates (hazard ratio: 3.41; 95% confidence interval: 1.14 to 10.16; p = 0.02), recurrences, and a composite of all-cause death, recurrence, and readmission rates due to cardiovascular causes. There were also higher rates of cardiogenic shock, peak creatine kinase levels, and increased use of inotropes and mechanical ventilation in the secondary TC cohort. Thus, the general conclusion of the current study led by Tornvall et al. that patients with TC and ACS have a similar prognosis should be perceived with caution. This is because many patients with secondary TC have increased morbidity and mortality due an alternate primary insult and/or cause. If the investigators could provide a subanalysis based on the etiology of TC (primary vs. secondary), it would be significantly valuable and would serve as a validation or refutation of this concept. Treatment approaches may also need to be tailored based on the presentation, with secondary TC forms needing more intensive monitoring and management.

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