Taking aspirin at bedtime instead of in the morning might reduce acute heart events, according a new study presented at the American Heart Association meeting in Dallas.

In the trial, the first to explore the timing of aspirin intake among cardiovascular disease patients, 290 patients took either 100mg upon waking or at bedtime during two three-month periods. At the end of each period, blood pressure and platelet activity was measured and while the former was not affected, aspirin platelet activity was reduced by 22 units (aspirin reaction units) when taken at night.

Low-dose daily aspirin, which thins the blood and makes it less likely to clot, is often recommended for people at high risk of heart disease. The study's lead researcher, Tobias Bonten of Leiden University Medical Center in the Netherlands, noted that because higher platelet activity "contributes to a higher risk of acute heart events, this simple intervention – switching aspirin intake from morning to bedtime – could be beneficial for the millions of patients with heart disease who take aspirin on a daily basis".