Contrary to previous report, aspirin DID lower 1st heart attack risk

The ARRIVE study assessed the impact of daily aspirin on heart attacks, strokes, and bleeding in a population at moderate risk of a first cardiovascular event. Moderate risk was defined as a 20-30% risk of a cardiovascular event in ten years. The study enrolled individuals with no prior history of a vascular event, such as stroke or heart attack. Men were at least 55 years old and had two to four cardiovascular risk factors, while women were at least 60 years old with three or more risk factors. Risk factors included smoking, elevated lipids, and high blood pressure.

In the per-protocol analysis, aspirin reduced the risk of total and nonfatal myocardial infarction (HR 0.53, 95% CI 0.36-0.79, p=0.0014; HR 0.55, 95% CI 0.36-0.84, p=0.0056, respectively). The relative risk reduction of myocardial infarction in the aspirin group was 82.1%, and 54.3% in the 50-59 and 59-69 age groups, respectively.

All safety analyses were conducted according to intention-to-treat. Gastrointestinal bleedings, which were mostly mild, occurred in 61 (0.97%) individuals in the aspirin group versus 29 (0.46%) in the placebo group (HR 2.11, 95% CI 1.36-3.28, p=0.0007). The overall incidence of adverse events was similar between treatment groups. Drug-related adverse events were more frequent in the aspirin (16.75%) compared to placebo (13.54%) group (p<0 .0001="" abdominal="" and="" being="" common="" disease="" gastro-oesophageal="" indigestion="" most="" nosebleeds="" p="" pain.="" reflux="" the="" upper="">
Professor Gaziano said: "Participants who took aspirin tended to have fewer heart attacks, particularly those aged 50-59 years, but there was no effect on stroke. As expected, rates of gastrointestinal bleeding and some other minor bleedings were higher in the aspirin group, but there was no difference in fatal bleeding events between groups."