Maori and Pacific Islanders' exposure to the bacteria that causes rheumatic fever means the standard heart drug streptokinase is likely to be less effective when they have heart attacks, say University of Otago researchers.
High rates of Group A streptococcal infection, the same infection which leads to rheumatic fever, meant many people would have antibodies to the drug, said Garry Nixon from the Department of General Practice and Rural Health in Dunedin.
"There's therefore a real risk that when they have a heart attack and are given this drug it will not work for them," he said.
The findings are in a University of Otago study, recently published in the British Medical Journal Clinical Pathology, and confirms Australian research that indigenous people with heart problems are more likely to have resistance to streptokinase - which is used to dissolve clots in arteries.
The study of 180 heart attack patients from the Hokianga, Thames and Central Otago showed the rural Hokianga community - with the highest proportion of Maori and lowest socio-economic status - had resistance to streptokinase medication 2.8 times higher than in Central Otago, which had the lowest proportion of Maori and higher socio-economic status, Nixon said.
That meant that newer fibrinolytic heart drugs, although more expensive, should be used for patients with heart attacks in predominantly Maori rural communities, he said.
Nixon said the study was a timely reminder of the need to exercise caution when translating the results of drug trials carried out on Caucasians to other ethnic groups such and Maori and Pacific Islanders.
People living in Samoa, the Cook Islands, French Polynesia and Tonga have some of the highest rates of rheumatic fever in the world.
Pacific Islanders living in New Zealand are 1.5 to 2 times more likely to have rheumatic fever than Maori.
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