The results of the largest trial of blood pressure lowering ever completed, the HOT study (Hypertension Optimal Treatment) were announced at the International Society of Hypertension meeting in Amsterdam in June, 1998. The main goal of the study was to investigate how much blood pressure should be lowered to prevent strokes and heart attacks, but a secondary aim was to investigate the effects of a low dose of aspirin. Nineteen thousand hypertensive patients were treated with a mixture of drugs to lower their blood pressure and were also given either one baby aspirin a day (a dose of 75 milligrams, equivalent to the 81 milligrams available in the US) or placebo.
Over a three-year follow-up period, patients taking aspirin had 36% fewer heart attacks than those taking placebo, but there was no effect on the number of strokes. The downside of taking aspirin was an increased risk of bleeding, although none proved fatal.
While these results certainly strengthen the case for taking aspirin if you have hypertension, we also point out that the patients in this study had very good blood pressure control. People whose blood pressure is uncontrolled are at increased risk of stroke from a hemorrhage (bleed) inside the brain, and it remains unclear whether aspirin would increase this risk.
