Low-Dose Aspirin for Primary Prevention of Cardiovascular Events in Japanese Patients 60 Years or Older With Atherosclerotic Risk Factors A Randomized Clinical Trial


Importance  Prevention of atherosclerotic cardiovascular diseases is an important public health priority in Japan due to an aging population.

Objective  To determine whether daily, low-dose aspirin reduces the incidence of cardiovascular events in older Japanese patients with multiple atherosclerotic risk factors.

Design, Setting, and Participants  The Japanese Primary Prevention Project (JPPP) was a multicenter, open-label, randomized, parallel-group trial. Patients (N = 14 464) were aged 60 to 85 years, presenting with hypertension, dyslipidemia, or diabetes mellitus recruited by primary care physicians at 1007 clinics in Japan between March 2005 and June 2007, and were followed up for up to 6.5 years, with last follow-up in May 2012. A multidisciplinary expert panel (blinded to treatment assignments) adjudicated study outcomes.

Interventions  Patients were randomized 1:1 to enteric-coated aspirin 100 mg/d or no aspirin in addition to ongoing medications.

Main Outcomes and Measures  Composite primary outcome was death from cardiovascular causes (myocardial infarction, stroke, and other cardiovascular causes), nonfatal stroke (ischemic or hemorrhagic, including undefined cerebrovascular events), and nonfatal myocardial infarction. Secondary outcomes included individual end points.

Results  The study was terminated early by the data monitoring committee after a median follow-up of 5.02 years (interquartile range, 4.55–5.33) based on likely futility. In both the aspirin and no aspirin groups, 56 fatal events occurred. Patients with an occurrence of nonfatal stroke totaled 114 in the aspirin group and 108 in the no aspirin group; of nonfatal myocardial infarction, 20 in the aspirin group and 38 in the no aspirin group; of undefined cerebrovascular events, 3 in the aspirin group and 5 in the no aspirin group. The 5-year cumulative primary outcome event rate was not significantly different between the groups (2.77% [95% CI, 2.40%-3.20%] for aspirin vs 2.96% [95% CI, 2.58%-3.40%] for no aspirin; hazard ratio [HR], 0.94 [95% CI, 0.77-1.15]; P = .54). Aspirin significantly reduced incidence of nonfatal myocardial infarction (0.30 [95% CI, 0.19-0.47] for aspirin vs 0.58 [95% CI, 0.42-0.81] for no aspirin; HR, 0.53 [95% CI, 0.31-0.91]; P = .02) and transient ischemic attack (0.26 [95% CI, 0.16-0.42] for aspirin vs 0.49 [95% CI, 0.35-0.69] for no aspirin; HR, 0.57 [95% CI, 0.32-0.99]; P = .04), and significantly increased the risk of extracranial hemorrhage requiring transfusion or hospitalization (0.86 [95% CI, 0.67-1.11] for aspirin vs 0.51 [95% CI, 0.37-0.72] for no aspirin; HR, 1.85 [95% CI, 1.22-2.81]; P = .004).

Conclusions and Relevance  Once-daily, low-dose aspirin did not significantly reduce the risk of the composite outcome of cardiovascular death, nonfatal stroke, and nonfatal myocardial infarction among Japanese patients 60 years or older with atherosclerotic risk factors.

Low-Dose Aspirin for Primary Prevention of Cardiovascular Events in Japanese Patients 60 Years or Older With Atherosclerotic Risk FactorsA Randomized Clinical Trial.


Importance  Prevention of atherosclerotic cardiovascular diseases is an important public health priority in Japan due to an aging population.

Objective  To determine whether daily, low-dose aspirin reduces the incidence of cardiovascular events in older Japanese patients with multiple atherosclerotic risk factors.

Design, Setting, and Participants  The Japanese Primary Prevention Project (JPPP) was a multicenter, open-label, randomized, parallel-group trial. Patients (N = 14 464) were aged 60 to 85 years, presenting with hypertension, dyslipidemia, or diabetes mellitus recruited by primary care physicians at 1007 clinics in Japan between March 2005 and June 2007, and were followed up for up to 6.5 years, with last follow-up in May 2012. A multidisciplinary expert panel (blinded to treatment assignments) adjudicated study outcomes.

Interventions  Patients were randomized 1:1 to enteric-coated aspirin 100 mg/d or no aspirin in addition to ongoing medications.

Main Outcomes and Measures  Composite primary outcome was death from cardiovascular causes (myocardial infarction, stroke, and other cardiovascular causes), nonfatal stroke (ischemic or hemorrhagic, including undefined cerebrovascular events), and nonfatal myocardial infarction. Secondary outcomes included individual end points.

Results  The study was terminated early by the data monitoring committee after a median follow-up of 5.02 years (interquartile range, 4.55–5.33) based on likely futility. In both the aspirin and no aspirin groups, 56 fatal events occurred. Patients with an occurrence of nonfatal stroke totaled 114 in the aspirin group and 108 in the no aspirin group; of nonfatal myocardial infarction, 20 in the aspirin group and 38 in the no aspirin group; of undefined cerebrovascular events, 3 in the aspirin group and 5 in the no aspirin group. The 5-year cumulative primary outcome event rate was not significantly different between the groups (2.77% [95% CI, 2.40%-3.20%] for aspirin vs 2.96% [95% CI, 2.58%-3.40%] for no aspirin; hazard ratio [HR], 0.94 [95% CI, 0.77-1.15]; P = .54). Aspirin significantly reduced incidence of nonfatal myocardial infarction (0.30 [95% CI, 0.19-0.47] for aspirin vs 0.58 [95% CI, 0.42-0.81] for no aspirin; HR, 0.53 [95% CI, 0.31-0.91]; P = .02) and transient ischemic attack (0.26 [95% CI, 0.16-0.42] for aspirin vs 0.49 [95% CI, 0.35-0.69] for no aspirin; HR, 0.57 [95% CI, 0.32-0.99]; P = .04), and significantly increased the risk of extracranial hemorrhage requiring transfusion or hospitalization (0.86 [95% CI, 0.67-1.11] for aspirin vs 0.51 [95% CI, 0.37-0.72] for no aspirin; HR, 1.85 [95% CI, 1.22-2.81]; P = .004).

Conclusions and Relevance  Once-daily, low-dose aspirin did not significantly reduce the risk of the composite outcome of cardiovascular death, nonfatal stroke, and nonfatal myocardial infarction among Japanese patients 60 years or older with atherosclerotic risk factors.

Trial Registration  clinicaltrials.gov Identifier: NCT00225849.

The World Health Organization estimates that annual global mortality due to cardiovascular diseases (including myocardial infarction and stroke) will approach 25 million by 2030.1 A recent study of secular trends in cardiovascular disease in Japan indicated that, from 1960 to 2000, the prevalence of smoking decreased and blood pressure control among hypertensive individuals improved significantly. Conversely, a steep increase in the prevalence of glucose intolerance, hypercholesterolemia, and obesity was observed,2 probably due to the adoption of Western diets and lifestyles. Over this period, a decreasing trend in stroke incidence has slowed, and the incidence of myocardial infarction has not changed.2 By 2030, it is estimated that 32% of the Japanese population will be 65 years or older.3 This aging population, combined with the increasing prevalence of well-documented risk factors, means that the prevention of atherosclerotic disease remains an important public health challenge in Japan.

In 2009, the Antithrombotic Trialists’ Collaboration (ATTC) reviewed the benefit-risk profile of low-dose aspirin for the primary prevention of vascular disease in a meta-analysis of 6 primary prevention trials. Use of low-dose aspirin was associated with a 12% proportional reduction in serious vascular events compared with no aspirin (annual event rate, 0.51% for aspirin and 0.57% for no aspirin; P = .001), mainly due to a reduction in nonfatal myocardial infarction of approximately 20%.4 Aspirin increased major gastrointestinal and extracranial bleeding compared with control (annual increase, 0.10% for aspirin and 0.07% for control; P < .001).4

In Japan, the use of aspirin for primary prevention of ischemic heart disease has not been widespread.5,6 The Japanese Primary Prevention Project (JPPP) was designed to determine whether once-daily, low-dose, enteric-coated aspirin reduces the total number of atherosclerotic events (ischemic heart disease and stroke) compared with no aspirin in Japanese patients 60 years or older with hypertension, dyslipidemia, or diabetes mellitus.

Low-Dose Aspirin Doesn’t Prevent VTE Recurrence But Does Reduce Vascular Events .


Aspirin maintenance therapy after venous thromboembolism — although not better than placebo at preventing recurrence — does reduce risks for major vascular events, according to a study presented at the American Heart Association meeting and published in the New England Journal of Medicine.

Researchers randomized some 800 patients with first episodes of unprovoked VTE to 100 mg of aspirin or placebo daily. All had completed therapy with anticoagulants.

During a median follow-up of roughly 3 years, VTE recurrence (the primary outcome) did not differ significantly between the groups. However, composite outcomes that included VTE, MI, stroke, major bleeding, and death (secondary endpoints) were reduced by about one third with aspirin.

Allan S. Brett writes in Journal Watch General Medicine: “After completing initial courses of anticoagulation, patients with unprovoked VTE are at high risk for recurrence. Indefinite continuation of warfarin lowers that risk substantially but confers considerable ongoing bleeding risk. Aspirin offers a reasonable compromise for such patients.”

Source: NEJM

Low-Dose Aspirin Might Not Interfere with Immunochemical Fecal Occult Blood Tests


Aspirin, currently on the list of drugs to avoid before undergoing screening for fecal occult blood, might not interfere with immunochemical forms of the test, according to a JAMA study.

As part of their preparation for screening colonoscopy, some 2000 patients were asked about regular use of drugs, including low-dose aspirin. All patients underwent two different immunochemical fecal occult blood tests (iFOBTs) to measure hemoglobin and hemoglobin-haptoglobin.

Based on the colonoscopy findings, iFOBT sensitivity results for advanced neoplasms were as follows:

  Hemoglobin Hemoglobin-Haptoglobin
Aspirin users 70.8% 58.3%
Aspirin nonusers 35.9% 32.0%

Specificities were slightly lower for aspirin users than nonusers (e.g., 85.7% vs. 91.1% for the hemoglobin-haptoglobin test).

The authors conclude: “Our study strongly suggests that use of low-dose aspirin does not hamper testing for fecal occult blood by immunochemical tests. On the contrary, our findings raise the hypothesis that test performance may be enhanced by temporary use of low-dose aspirin, a hypothesis that needs replication in larger samples and followed up in further research.”