We examined whether the efficacy of low-dose acetylsalicylic acid (aspirin) for primary prevention of cardiovascular events is influenced by blood pressure (BP) using data from patients aged 60–85 years with hypertension, dyslipidemia, and/or diabetes, but without cardiovascular disease of the Japanese Primary Prevention Project.
All patients had received aspirin (100 mg/day) or no aspirin. BP subgroups were defined as low (average SBP from the baseline to the year of the events <130 mmHg), moderate (≥130 and <140 mmHg), and high (≥140 mmHg). The mean duration of follow-up was 5.02 years.
In hypertensive patients (n = 12 278) aspirin had no significant impact on the primary outcome of death from cardiovascular disease, nonfatal stroke, and nonfatal myocardial infarction. On the other hand, aspirin increased the incidence of serious extracranial hemorrhage [hazard ratio, 1.81; 95% confidence interval (CI), 1.18–2.77; P = 0.0064] and tended to increase hemorrhagic stroke (hazard ratio, 1.75; CI, 0.99–3.07; P = 0.053). Aspirin had no effect on the primary outcome in any of the BP subgroups, and was associated with increased hemorrhagic stroke in the high BP group (hazard ratio, 3.51; CI, 1.29–9.51; P = 0.014); serious extracranial hemorrhage was elevated or tended to elevate in the moderate (hazard ratio, 2.53; CI, 1.18–5.45; P = 0.017) and high (hazard ratio, 2.14; CI, 1.00–4.56; P = 0.050) BP groups.
In aged Japanese hypertensive patients, these data demonstrated no overall benefit of low-dose aspirin therapy although treatment was associated with an elevated risk of hemorrhagic events.
aDepartment of Internal Medicine, Kitamura Memorial Clinic, Tokyo
bDepartment of Cardiology, Shin-Oyama City Hospital, Tochigi
cClinical Research Support Center, Center for Epidemiology and Preventive Medicine, The University of Tokyo Hospital
dInternational University of Health and Welfare, Center for Brain and Cerebral Vessels, Sanno Hospital and Sanno Medical Center
eClinical Trial Department, Cancer Institute Hospital
fTeikyo Academic Research Center, Teikyo University
gDiabetes and Lifestyle Disease Center, Fukujyuji Hospital
hDepartment of Internal Medicine, Sugawara Medical Clinic, Japan Physician's Association
iClinical Laboratory, Keio University School of Medicine
jDepartment of Hematology/Oncology, Tokai University Hachioji Hospital
kGraduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
Correspondence to Katsuyuki Ando, Department of Internal Medicine, Kitamura Memorial Clinic, Shin-Koiwa 1-49-10 5-7F, Katsushika-ku, Tokyo 124-0024, Japan. Tel: +81 3 6231 5931; fax: +81 3 6231 5932; e-mail: email@example.com
Abbreviations: aspirin, acetylsalicylic acid; ASPREE, Aspirin in Reducing Events in Elderly; BAT, Bleeding with Antithrombotic Therapy; BP, blood pressure; CI, confidence interval; JPAD, Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes; JPPP, Japanese Primary Prevention Project; MRC, Medical Research Council; TIA, transient ischemic attack
Received 22 June, 2018
Accepted 4 December, 2018