Benefit and harm of low-dose aspirin in well-treated hypertensives at different baseline cardiovascular risk

Background The effects of aspirin in subjects without cardiovascular disease are controversial. In the intensively treated patients of the Hypertension Optimal Treatment (HOT) Study, randomization to low-dose aspirin (75 mg daily) versus placebo significantly reduced cardiovascular events (-15%) and myocardial infarction (-36%), but increased major bleedings (+65%). The present analyses of HOT Study data aim at identifying subgroups of hypertensives with different benefit-to-harm ratios from aspirin, in order to provide recommendations about the use of aspirin in hypertension. Methods The 18 790 hypertensive patients (aspirin 9399, placebo 9391; average treatment duration 3.8 years) were stratified for global cardiovascular risk and for individual risk factors. Subgroup-treatment interaction analyses (end points: cardiovascular events, myocardial infarction, major bleedings) were performed by a Cox proportional hazard model. Relative and absolute benefits and harms were calculated. Results Interaction analyses indicated that of all subgroups, only patients with serum creatinine > 1.3 mg/dl had a significantly greater reduction of cardiovascular events and myocardial infarction (-13 and -7/1000 patient-years), while risk of bleeding was not significantly different between subgroups. In addition to patients with higher creatinine, a favourable balance between benefit and harm of aspirin was found in subgroups of patients at higher global baseline risk and baseline systolic pressure greater than or equal to180 or diastolic pressure greater than or equal to107 mmHg. Conclusions Low-dose aspirin should be recommended to well-treated hypertensive patients with even moderate increase in serum creatinine. Aspirin may also be recommended in well-treated hypertensives at higher global cardiovascular risk or higher initial blood pressures. (C) 2002 Lippincott Williams Wilkins.