Takotsubo syndrome — “broken heart syndrome” — presents like a heart attack in almost every respect: chest pain, an abnormal ECG, elevated cardiac enzymes. The decisive difference is invisible without imaging: the coronary arteries are not blocked. Researchers have now built a blood-based score that claims to tell the two apart before anyone reaches the catheterisation lab.
What takotsubo actually is
The name comes from a Japanese octopus trap, which the affected heart resembles on imaging: the apex of the left ventricle balloons outward while the base contracts normally. It is typically triggered by intense emotional or physical stress, and it disproportionately affects women, particularly after menopause.
The prevailing explanation involves a surge of catecholamines — adrenaline and related stress hormones — producing a form of myocardial stunning rather than tissue death from a blocked vessel. The muscle is not infarcted; it is temporarily incapacitated.
Its reputation as benign is misleading. In-hospital complications and mortality are comparable to acute coronary syndrome, and a meaningful proportion of patients develop heart failure, arrhythmias or cardiogenic shock. It is a serious condition that happens to resolve in survivors.
The diagnostic problem today
Because takotsubo mimics infarction, the standard route to diagnosis is exclusion: take the patient to the catheterisation laboratory and demonstrate that the coronary arteries are clear. Many patients therefore undergo an invasive procedure whose principal result is to rule something out.
Angiography is generally safe but not risk-free — vascular access complications, contrast exposure, radiation — and it consumes catheterisation lab capacity and specialist time.
The BioTAK score
Scientists at the University of Zurich, with collaborators at Greifswald and Imperial College London, combined a patient’s biological sex with a panel of blood biomarkers, including two newly identified proteins linked to stress-response signalling and plaque stability. Machine learning was used to identify the most informative markers.
The resulting score classified patients with nearly 90% accuracy, validated in nearly 1,800 patients drawn from registries totalling over 3,600, and published in the European Heart Journal.
“A simple combination of blood biomarkers and biological sex can identify these patients with remarkable accuracy even before cardiac catheterisation,” the researchers said.
Including sex as a variable is a real choice
Building biological sex into a diagnostic score is unusual and worth noting. It works because the epidemiological skew is genuinely extreme — takotsubo is overwhelmingly a condition of women, particularly older women.
The risk is the mirror image. A score that leans on sex will be least reliable in men, who are the minority of takotsubo patients but not a negligible one, and who tend to present with worse outcomes. Performance in that subgroup is the number worth examining closely.
Why the errors are not symmetric
This is the point that should govern how the score is deployed, and it is not a matter of overall accuracy.
Calling a takotsubo patient a heart attack leads to an unnecessary catheterisation — wasteful and mildly risky. Calling a heart attack a takotsubo delays reperfusion in someone with an occluded coronary artery, and in myocardial infarction the relationship between time and irreversible muscle loss is direct and unforgiving.
“Nearly 90% accuracy” does not distinguish between those two failure modes. A score can only safely be used to avoid angiography if its false-negative rate for genuine infarction is extremely low — a much harder standard than good overall performance, and the specific figure clinicians will demand before changing practice.
Where it might fit instead
A more realistic near-term role is not replacing catheterisation but informing it. Knowing at presentation that takotsubo is likely changes how a case is approached: the team anticipates the imaging findings, prepares for the complications takotsubo actually produces, and can counsel the patient and family before rather than after the procedure.
Existing clinical scores already estimate takotsubo probability from presentation features. A validated biomarker panel would strengthen that assessment considerably without requiring anyone to skip the definitive test.
An underrecognised condition
There is a second benefit that has nothing to do with avoiding procedures. Takotsubo is underrecognised, and patients whose arteries are found to be clear are sometimes discharged with a vague reassurance rather than a diagnosis — missing the follow-up, the heart-failure monitoring and the recurrence risk that a named condition would trigger.
A test that puts takotsubo on the table at presentation makes the diagnosis more likely to be recorded and managed properly.
What still has to happen
This is a validated diagnostic score, not an implemented test. The biomarker panel must be available as an assay with a turnaround fast enough to matter in an emergency department — a result arriving after the catheterisation decision has been made is of no use.
Registry populations are also cleaner than the patients who actually arrive at hospital, where comorbidity, atypical presentation and concurrent illness blur the picture. Real-world implementation studies would need to confirm the score holds up, and specifically that it holds up in the cases where it is hardest to be right. Research news, not medical advice.