Protein linked to heart attacks can identify heart patients with increased risk of death

New research shows a protein linked to heart attacks can identify patients with an irregular heartbeat.

The study, conducted by researchers from the National Institute of Health Research Health Informatics Collaborative (NIHR-HIC) led by Imperial College Healthcare NHS Trust and Imperial College London, draws on data from more than 3000 patients over seven years.

Patients arriving at A & E with atrial fibrillation, also known as irregular heart rhythms, who were found to have above normal levels of the protein troponin in their blood, were more likely to die than those with low levels of the protein.

Troponin is a protein involved with the contraction of muscles which is released into the bloodstream after a heart attack.

To determine whether a patient is having a heart attack, clinicians check troponin levels alongside other tests.

Clinicians rarely act on troponin level results unless they are shown to be extremely high.  

Amit Kaura, lead author of the research and NIHR clinical research fellow with the National Heart and Lung Institute at Imperial College London, said:

“In patients with atrial fibrillation, clinicians currently only act on the results of troponin tests if levels are very high.

“That’s because, until now, there has been no decisive evidence to link troponin levels in these patients with increased risk of mortality.

“Our results clearly show that even troponin levels that are only just above the upper limits of normal should be taken very seriously in patients presenting with atrial fibrillation.

“Clinicians should consider using an angiogram to look for underlying coronary artery disease in any patient with atrial fibrillation who has an increased troponin level.”

The new study found that the risk of death for patients with atrial fibrillation increased even when their troponin levels were only slightly higher than normal.

The study also found that when patients had a coronary angiogram – a specialist X-ray to determine blockages in the blood supply to the heart – their risk of death was substantially lower.

However, fewer than half of patients with the highest levels of troponin underwent this procedure.

Amit Kaura also said:

“Our research found a clear link between troponin and mortality risk in patients with atrial fibrillation and that risk was lower in patients who underwent coronary angiogram.

“However, an angiogram is just a diagnostic test.

“We now need a clinical trial to investigate this link further, to see how diagnosing and treating coronary artery disease in patients with atrial fibrillation and elevated troponin can have an impact on mortality risk.”