22 January 2015

NICE-approved test 'could double diagnoses of heart attacks in women'

A new study suggests that a NICE-approved test for heart attacks could detect twice as many heart attacks in women than current standard tests.

Published in the BMJ, the research found that a test which NICE recommends for speeding up diagnosis, could also double the proportion of women who were diagnosed with a heart attack and so bring rates in line with those among men.

Around 700,000 people are admitted to emergency departments with acute coronary syndrome each year, usually with symptoms of chest pain.

To diagnose whether a heart attack has occurred in these cases, doctors can measure the level of a protein called troponin in the blood. This is because troponin is often released when the heart has been damaged due to a heart attack.

In September last year, NICE published guidance which recommends two new high-sensitivity troponin tests.

The tests detect lower levels of troponin in the blood than standard tests, and so can detect a change in levels of troponin earlier, allowing patients who have not had a heart attack to be discharged earlier.

The guidance recommends both the Elecsys troponin T high-sensitive assay and the ARCHITECT STAT high-sensitivity troponin I assay as biomarkers for heart attack. Both tests are of higher sensitivity than conventional biomarkers and so allow for earlier detection of changes in troponin levels.

The new research into the diagnostic thresholds of troponin among men and women, suggests that the ARCHITECT STAT troponin-I test may double the diagnosis of heart attack in women, and so identify those at high risk of repeat heart attacks and death.

Researchers compared the rates of diagnosis in this test with standard tests in 1,000 men and women admitted to the Royal Infirmary of Edinburgh hospital with chest pain.

They found that the higher sensitivity test increased diagnosis of myocardial infarction from 11 per cent to 22 percent in women, and increased rates from 19 to 21 per cent in men.

Professor Peter Weissberg, Medical Director at the British Heart Foundation which funded the research, said: “This research has shown that the results of the commonly used troponin blood test are significant at different levels in men and women. When the researchers took this into account, they found that twice as many women would be diagnosed with a heart attack.

“If these results are confirmed in the much larger clinical trial we’re funding, these results suggest that using a high sensitivity troponin test, with a threshold specific to each gender, could save many more women’s lives by identifying them earlier to take steps to prevent them dying or having another, bigger heart attack.”

Dr Anoop Shah, research author and Clinical Lecturer in Cardiology at the University of Edinburgh, add: “Our findings suggest one reason for the difference in heart attack diagnosis rates of men and women is that we, as doctors, may have been using a threshold for troponin testing that is too high in women.”