A systematic review of biomarkers in Takotsubo syndrome: A focus on better understanding the pathophysiology

Background: The diagnosis of Takotsubo syndrome is made based on clinical presentation, ECG, biomarker, imaging and coronary angiography. There is a lack of diagnostic biomarkers that can discriminate patients with Takotsubo syndrome from those with acute myocardial infarction (AMI) and provide clinical monitoring and prognostic information in the long-term.

Methods: A literature search of published Takotsubo syndrome biomarkers from PubMed was performed. All studies that included numerical biomarker data on Takotsubo syndrome was included. Exclusion criteria was any study without an AMI cohort for comparison in the acute phase biomarkers or due to the absence of numerical values. The results were tabulated in table form with results expressed as either mean ± SD or median (interquartile range).

Results: The literature search produced 14 relevant studies that met search criteria. The results showed; high sensitivity Troponin I (3.21 ± 4.4 vs 34.4 ± 37 ng/ml), BNP [972 (578.5-1671.0) pg/L vs 358 (50.5-688.0) pg/L in NSTEMI and vs 381 (106.0-934.0) pg/L in STEMI] and BNP/Troponin I ratio [642 (331.8-1226.5) vs 184.5 (50.5-372.3) pg/ug in NSTEMI and 7.5 (2.0-29.6) pg/ug in STEMI] patients.

Discussion: This study is limited by many studies being retrospective cohort studies. This data shows that acutely troponin is raised in Takotsubo syndrome but not enough to be discriminating from AMI. BNP level is significantly raised in Takotsubo syndrome compared to AMI.

Conclusion: Current specificity of acute and chronic biomarkers for Takotsubo syndrome is lacking and further work is needed to address the gap in knowledge.