“We demonstrate that having a non-O blood group is associated with a 9 per cent increased risk of coronary events and a 9 per cent increased risk of cardiovascular events, especially myocardial infarction (heart attack),” said Tessa Kole from University Medical Centre Groningen in the Netherlands.
Researchers studied 13,62,569 subjects from about 11 prospective cohorts, described in nine research articles. There were a total of 23,154 cardiovascular events.
They analysed the association between blood groups and all coronary events, combined cardiovascular events, and fatal coronary events.
Researchers found that the odds ratio (OR) for all coronary events was significantly higher in carriers of a non-O blood group.
The OR for combined cardiovascular events was significantly higher in non-O blood group carriers.
The analysis of fatal coronary events did not show a significant difference between people with O and non-O blood groups, researchers said.
The higher risk for cardiovascular events in non-O blood group carriers may be due to having greater concentrations of von Willebrand factor – a blood clotting protein, researchers said.
Non-O blood group carriers, specifically those with an A blood group, are known to have higher cholesterol.
Galectin-3 protein, which is linked to inflammation and worse outcomes in heart failure patients, is also higher in those with a non-O blood group.
“Blood group should be considered in risk assessment for cardiovascular prevention, together with cholesterol, age, sex and systolic blood pressure,” Kole said.