Aspirin in hypertension

• for primary prevention of cardiovascular disease the recommended dose is aspirin 75 mg per day
  
  
• aspirin was previously recommended for primary prevention in well-controlled hypertensive patients (with blood pressure less than 150/90 mmHg) aged 50 years or over where there are no contraindications to aspirin and at least one of the following (1):
  • evidence of target organ damage e.g. renal impairment, left ventricular hypertrophy
  • a 10 year cardiovascular disease risk * >= 20%
  • type II diabetes mellitus
  • however the evidence concerning the use of aspirin in primary prevention is controversial:
    • there is evidence from a meta-analysis that aspirin in the primary prevention setting can reduce the risk of MI (but not stroke); however aspirin use is associated with a significant increased risk of bleeding (2)
    • another meta-analysis revealed a significant reduction in cancer risk associated with aspirin use and the authors suggested that '..although the reduction in risk of ischaemic vascular events on aspirin in healthy individuals is partly off set by a small increase in risk of non-fatal bleeding complications the balance of risk and benefit will now be altered by the reduction in cancer deaths after 5 years' treatment. Our analyses show that taking aspirin daily for 5-10 years would reduce all-cause mortality (including any fatal bleeds) during that time by about 10% (relative risk reduction). Subsequently, there would be further delayed reductions in risk of cancer death, but no continuing excess risk of bleeding...potentially justifying added costs to reduce bleeding complications, such as co-prescription of a proton-pump inhibitors..'
    • NICE guidance currently does not suggest the use of aspirin in hypertensive patients in a primary prevention setting (4)
      
      
• for secondary prevention - 75mg of aspirin is recommended

Reference:

1. Williams B, Poulter NR, Brown MJ, Davis M, McInnes GT, Potter JF, et al. Guidelines for management of hypertension: report of the fourth working party of the British Hypertension Society, 2004 BHS IV. J Hum Hypertens 2004;18: 139-85
2. Antithrombotic Trialists' (ATT) Collaboration, Baigent C, Blackwell L, Collins R, Emberson J, Godwin J, Peto R, Buring J, Hennekens C, Kearney P, Meade T, Patrono C, Roncaglioni MC, Zanchetti A. Lancet. 2009 May 30;373(9678):1849-60.
3. Rothwell PM. Eff ect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials.www.thelancet.com Published online December 7, 2010 DOI:10.1016/S0140-6736(10)62110-1
4. NICE (November 2016). Hypertension - management of hypertension in adults in primary care.