Drug resistance raises coronary risk
One in four coronary artery disease patients is resistant to aspirin's ability to prevent blood clotting, meaning they are four times more likely to suffer heart attacks or strokes than patients who respond to the cheap pills, a University of Hong Kong study shows.
About 50,000 people in Hong Kong have coronary artery disease, of whom 90 per cent need to take aspirin every day to protect their hearts.
But a study conducted by the university's department of medicine between 2002 and 2004 showed 125 of 468 patients with stable coronary artery disease were aspirin-resistant, meaning the drug did not reduce the risk of blood clots.
The researchers monitored the patients' health and found 15.6 per cent of the aspirin-resistant people suffered heart attacks, strokes or other serious health problems during that period, compared with 5.3 per cent of those responsive to aspirin.
The risk of patients resistant to aspirin suffering a heart attack were 3.8 times that for patients responsive to the pills. Strokes were 4.1 times more likely. 'We are not sure what causes aspirin resistance but we do know that older people and women are more likely to be aspirin-resistant,' said Chen Wai-hong, honorary clinical assistant professor in the department.