New test shows rise in heart attack rates

Thinking you are dying of a heart attack and seeking emergency treatment only to be told you are perfectly healthy might be an embarrassing relief.

Every year more than 500,000 people are taken to hospital, often by ambulance with siren blaring, suffering from acute chest pains. But more than three out of four are discharged without a deleterious diagnosis.

Now a new blood test suggests as many as one in three of those patients did in fact have a minor heart attack. More important, when the test was introduced at the Royal Infirmary of Edinburgh and the extra heart attack victims were treated it halved the risk of their being readmitted to hospital – or dying from – another heart attack within a year.

The new test is more sensitive than those in standard use and detected heart muscle damage not picked up by them. It measures a protein – troponin – released when heart muscle cells are damaged through being starved of oxygen owing to a blood clot blocking a coronary artery during a heart attack.

Researchers studying the more sensitive test found it detected troponin at levels four times lower than before, revealing patients with less serious, but still significant, heart damage.

Dr Nicholas Mills, of the British Heart Foundation Centre for Cardiovascular Science at the University of Edinburgh, said: "Unfortunately, the use of outdated diagnostic thresholds for troponin continues to be widespread and lowering this threshold remains a highly contentious issue among doctors. The research shows it is not just patients with major heart attacks where treatment can make a difference. Even patients with comparatively minor heart damage benefit from these treatments."

The study, published in the Journal of the American Medical Association, analysed data from more than 2,000 patients admitted to the Royal Infirmary of Edinburgh with suspected heart attacks.

Professor Peter Weissberg, medical director at the British Heart Foundation, said: "Over recent years it has become clear that people who suffer heart pain but only a small amount of heart damage are at a very high risk of going on to have a larger, potentially fatal, heart attack if left untreated. This test will help doctors identify this vulnerable group of patients.

"If further studies corroborate these findings there will be considerable pressure on the NHS to adopt the new test as the standard for patients with chest pain."

More than 20 million people attended A&E departments in England last year. Up to 10 per cent of those visits were for suspected heart attacks.