Broken heart syndrome or heart attack? A blood test score sorted most patients before angiography

Takotsubo syndrome is sometimes called broken heart syndrome because it often follows a shock: bereavement, a frightening event, an argument, or a physical stress such as surgery. The heart muscle suddenly weakens. On arrival at hospital it looks almost exactly like a heart attack, and the usual way to tell the two apart is an invasive catheter test of the heart’s arteries.

A study in the European Heart Journal built a blood test score to separate the two conditions earlier. In more than 3,600 patients, it discriminated well between them and gave almost nine in ten patients a likely diagnosis before angiography.

Why takotsubo is mistaken for a heart attack

MedlinePlus explains that a heart attack, also called a myocardial infarction, is a type of heart disease, meaning blocked blood flow damages the heart muscle, and that if you get quick treatment, you may be able to prevent or limit damage to the heart muscle. That urgency is why doctors assume a heart attack until proven otherwise.

Takotsubo produces the same chest pain, breathlessness and abnormal heart tracings, but the arteries are open. As the authors note, diagnosis currently relies on history, repeated cardiac imaging, and exclusion of a culprit coronary artery lesion, generally with invasive coronary angiography (ICA), a catheter threaded to the heart.

How the BioTAK score was built

The researchers drew on 3615 patients with ACS or TTS, meaning acute coronary syndrome, the group of conditions that includes heart attacks, or takotsubo syndrome. Blood samples had been taken before angiography.

They built the score in one group of 1,823 patients, using machine learning to pick the most useful markers, and then tested it in a separate group of 1,792. Takotsubo was rare in both, about 4% of patients, which mirrors real life and makes the test harder.

What the blood test showed

The final score combined five items: four blood markers and the patient’s sex. The markers reflect strain on the heart muscle, tightening of blood vessels linked to stress hormones, unstable artery plaque, and LDL cholesterol.

It performed well in both groups. Using predefined rule-in and rule-out thresholds, the score stratified almost 90% of patients to a likely diagnosis before angiography. Accuracy was highest in the group it was built on and held up well in the independent group.

Why an early blood test could help

For patients, earlier clarity could mean fewer invasive procedures and quicker, more appropriate treatment. Takotsubo is managed differently from a blocked artery, and some treatments aimed at heart attacks are unnecessary for it.

The authors suggest the score can support the early identification of TTS, help streamline diagnostic pathways, and might reduce potentially avoidable invasive procedures. The markers also point to real biological differences between the conditions, which could guide research into why takotsubo happens.

What a diagnostic score study cannot show

The patients came from registries of people already confirmed to have one condition or the other, which is cleaner than an emergency department where many other causes of chest pain turn up. Performance in that messier setting is not yet known.

Some of the markers are not standard hospital tests, so the score is not available on request today. And no trial has yet tested whether using it changes decisions or outcomes; until then, angiography remains the way to rule out a blocked artery.

What this changes for broken heart syndrome care

Nothing about what to do in the moment: chest pain, sudden breathlessness or collapse still means calling emergency services. Both conditions are serious and both need hospital care.

For people who have had takotsubo, and for their doctors, the study adds to the case that it is a distinct condition with its own biological signature, not simply a heart attack without blocked arteries.