Reply to: More data on the association of Takotsubo syndrome and stroke are warranted

We thank Drs. Stollberger and Finsterer for their insightful comments in a letter to the editor regarding our referenced study [ [1] Jessen N. et al. Takotsubo syndrome and stroke risk: a nationwide register-based study. Int. J. Cardiol. 2023; 392131283 Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar ]. We hereby address eight points raised by Drs. Stollberger and Finsterer: 1.We acknowledge de novo atrial fibrillation (AF) as a risk factor for stroke/TIA. Ten-day de novo AF risk was 1.0% for Takotsubo patients. 2.“Prior” stroke/TIA was any record of such in the Danish National Patient Register from 1977 until admission with Takotsubo. 3.We did not include peripheral or mesenteric events, as the focus in our study was on cerebrovascular events. 4.A correlation between Takotsubo and catecholamines have previously been reported [ [3] Y-Hassan S. Tornvall P. Epidemiology, pathogenesis, and management of takotsubo syndrome. Clin. Auton. Res. 2018; 28: 53-65 Crossref PubMed Scopus (120) Google Scholar ]. Due to an association between beta-2 agonists and Takotsubo, we included beta-2-agonists as a covariate. 5.We especially thank Drs. Stollberger and Finsterer for pointing out low prevalences of hypertension and use of antiplatelets and lipid-lowering drugs. We regrettably discovered errors in the numbers for the myocardial infarction (MI) cohort. We will humbly request an erratum. 6.Very low incidences of stroke/TIA and mortality when stratifying on pre-existing ischemic heart disease and chronic obstructive pulmonary disease, respectively, were found. Statistics Denmark regulations do not permit reporting of numbers ≤3, rendering stratification on these factors unfeasible. 7.Regrettably, imaging data to differentiate stroke according to the TOAST-classification is not available from the Danish national health registries [ [2] Schmidt M. et al. The Danish National Patient Registry: a review of content, data quality, and research potential. Clin. Epidemiol. 2015; 7: 449-490 Crossref PubMed Scopus (2847) Google Scholar ]. 8.A presumed cardiovascular cause of death was found for 40% of those dying in the Takotsubo cohort, 39.6% for AF, 71.1% for MI, and 23.1% for background population controls.