Taking low-dose aspirin as a preventative measure could up resistance to the drug amongst patients with coronary artery disease, according to researchers from the University of Hong Kong writing in the American Journal of Medicine.

The study enrolled more than 460 patients with stable heart disease who were taking various doses of the anti-inflammatory drug (80 to 325mg) for four weeks. Results demonstrated that more than one-quarter of all patients had some resistance to aspirin – but particularly amongst patients taking 100mg or less. The researchers have called for larger randomized trials to be conducted in order to determine the optimal aspirin dose for preventing cardiovascular complications, adding: “Whether or not escalating the aspirin dose among aspirin-resistant patients would reverse their aspirin responsiveness and hence their clinical risk remains to be proved.”