Kazuyuki Shimada, University of Shin-Oyama City Hospital, Tochigi, Japan, presented data from the Japanese Primary Prevention Project study [JPPP; Ikeda Y et al. JAMA. 2014], which found that daily, low-dose aspirin did not reduce the risk of cardiovascular disease (CVD) in elderly Japanese patients with risk factors for atherosclerosis.

The use of aspirin as a preventative for CVD is controversial. Although meta-analyses have reported benefits of aspirin for CVD prevention, risks have also been documented [Raju NC, Eikelboom JW. Curr Opin Cardiol. 2012]. In addition, the US Food and Drug Administration (FDA) recently stated that current evidence does not support the general use of aspirin for the prevention of CVD [FDA. Use of Aspirin for Primary Prevention of Heart Attack and Stroke. 2014]. The purpose of the JPPP trial was to evaluate if the daily use of low-dose aspirin was effective in reducing the risk of cardiovascular (CV) events in an elderly Japanese population with risk factors for atherosclerosis.

In the prospective, randomized, open-blinded trial, 14 658 Japanese patients aged 60 to 85 years with hypertension, dyslipidemia, or diabetes mellitus were randomly assigned in a 1:1 fashion to receive enteric-coated aspirin 100 mg/d or no aspirin, in addition to their current medication to control underlying disease(s). The median follow-up was 5.02 years. At baseline, the mean age was about 71 years, about 42% were men, the mean body mass index was 24 kg/m², and approximately 13% of the patients were current smokers.

The primary end point was a composite of death from CV causes, nonfatal stroke, and nonfatal myocardial infarction (MI). Secondary end points included a composite of the primary end point plus transient ischemic attack, angina pectoris, and arteriosclerotic disease that required intervention. Secondary end points also included individual end points that made up the composite end points and death from causes other than CV events, all-cause mortality, and serious extracranial hemorrhage.

There was no significant difference in the proportion of patients who experienced the primary end point among the aspirin and no-aspirin arms at year 6 (2.77% with aspirin vs 2.96 with placebo; HR, 0.94; 95% CI, 0.77 to 1.15; P = .54). The results were consistent among major subgroups. Several secondary efficacy end points reached appeared to be lower with aspirin, including nonfatal MI (HR, 0.53; 95% CI, 0.31 to 0.91; P = .02) and transient ischemic attacks (HR, 0.57; 95% CI, 0.32 to 0.99; P =.04).

Aspirin treatment resulted in a significantly greater rate of serious extracranial hemorrhage (HR, 1.85; 95% CI, 1.22 to 2.81; P = .004). In addition, patients who received aspirin were more likely to experience abdominal discomfort, gastroduodenal ulcer, abdominal pain, heartburn, reflux esophagitis, erosive gastritis, gastrointestinal hemorrhage, and nausea.

Prof Shimada concluded that the data from the JPPP trial suggest that daily low-dose aspirin is not effective in decreasing the risk of CVD in elderly Japanese patients. However, he pointed out that the study was terminated early before statistical power was reached, which may have attributed to the observed lack of benefit for the primary end point.