SWIFTER diagnosis for people suspected of having a heart attack could be on
the way, thanks to the discovery of a new biochemical marker. Life-saving
treatment could start earlier for people who need it鈥攁nd those who don鈥檛
could avoid therapy that may harm them.
Measuring blood levels of a substance called fatty acid binding protein
(FABP) could allow doctors to diagnose a heart attack between one and three
hours earlier than standard methods, say Calum McNeil and his colleagues at the
University of Newcastle. 鈥淲e hope that if we get this into accident and
emergency wards we can confirm or exclude myocardial infarction much earlier,鈥�
explains McNeil.
If someone has a major heart attack, abnormalities called 鈥淨 waves鈥� show up
immediately on an electrocardiogram (ECG). But things are hazier after less
serious heart attacks: Q waves don鈥檛 usually appear on the ECG, so doctors have
to weigh up the risk factors and make an educated guess.
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A firm diagnosis of a heart attack may have to wait four to six hours, when
blood tests can reveal a telltale rise in levels of myoglobin, a substance
released by injured cardiac tissue. The researchers say it takes only three
hours for blood levels of FABP to rise sufficiently to confirm a heart
attack.
The team鈥檚 work builds on Japanese research published last year in
Clinical Chemistry (vol 43, p 1372), suggesting that FABP might have a role
in diagnosing heart attacks.
Phil Adams, consultant cardiologist at Newcastle鈥檚 Royal Victoria Infirmary,
says a test for FABP could have 鈥減rofound economic and human advantages鈥� by
saving 鈥渟omething like 40 per cent to 50 per cent bed occupancy in a coronary
care unit鈥�.
James Hooper, a pathologist specialising in cardiac biochemistry at the Royal
Brompton Hospital, London, says: 鈥淭his is potentially very useful in cases where
ECGs are not clear-cut鈥攑rovided it can be shown to be accurate and
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