- Hypertension is BP above which intervention has been shown successfully to reduce cardiovascular risk.
- It is the most common treatable risk factor for cardiovascular disease in patients over 50 years.
- More than one quarter of the world's adult population had hypertension in 2000; this is predicted to increase to 29 per cent by 2025.
- It is becoming increasingly difficult for our patients to reach new lower BP targets.
What is the evidence?
- In the ASCOT study, 19,257 patients were randomised to one of two antihypertensive regimens. Patients in the amlodipine/perindopril group had a significant relative-risk reduction in all-cause mortality, all major cardiovascular endpoints and new-onset diabetes, compared with those in the atenolol/bendroflumethiazide group (Lancet 2005; 366: 895-906). The study was stopped early in view of these results.
- Young white and black people can be characterised as high- and low-renin hypertensives, corresponding to their better response to treatment with ACE inhibitors and beta-blockers or calcium-channel blockers and diuretics, respectively (BMJ 2006; 332: 833-6).
- A meta-analysis has found that beta-blockers do not protect patients from stroke as well as alternatives (Lancet 2005; 366: 1,545-53).
- A recent systematic review found the association of antihypertensive drugs with incident diabetes is lowest for angiotensin receptor blockers and ACE inhibitors followed by calcium-channel blockers and placebo, beta-blockers and diuretics in rank order (Lancet 2007; 369; 201-70).
- Sodium reduction, previously shown to lower BP and prevent hypertension, also seems to protect against cardiovascular disease, according to one study (BMJ 2007; 334: 885-8).
Implications for practice
- Revised BHS guidelines recommend ACE inhibitors as first-line treatment in patients under 55, and thiazides in those over 55.
- NICE has downgraded the role of beta-blockers in hypertension in its guidance.
- It is accepted best practice to choose therapeutic agents that are likely to do more good than harm given each patient's risk factors. - Only a third of patients prescribed antihypertensives and lipid-lowering therapy are still taking both after six months (Arch Intern Med 2005; 165: 1,147-52).
- British Hypertension Society guidelines: www.bhsoc.org
- NICE guidelines: www.nice.org.uk
Dr Louise Newson is a GP in the West Midlands and author of 'Hot Topics for MRCGP and General Practitioners' PasTest 2006
- Hypertension is still underdiagnosed and undertreated.
- The type of drug is probably less important than the BP control achieved.
- Salt reduction is important.
- Compliance with antihypertensive drugs is poor.