One of the targets for the NHS in the Department of Health’s Priorities and Planning Framework 2003–2006 is to contribute to a national reduction in death rates from CHD in people under 75 of at least 25% by 2005 compared to 1995–1997. Practice-based registers should now cover not only patients with established CHD but also the majority of patients at high risk, particularly those with hypertension, diabetes and a body mass index greater than 30.¹ Advice on interventions to reduce the risk of CHD (smoking cessation, increasing physical activity, healthy eating and a reduction in being overweight or obese) should be included in systematic treatment regimens. The recently updated Joint British Societies Coronary Risk Prediction charts and computer program now aim to assess 10 year risk of cardiovascular disease rather than risk of CHD; the objective being to aid treatment of all cardiovascular events including stroke. The charts are simpler than the 1999 version with only three age groups. Separate charts for Type 2 diabetes are no longer provided.²

Hypertension

The recommended blood pressure target for most patients is 140/85mmHg or lower. For patients with renal impairment or diabetes or established cardiovascular disease the target is lower at 130/80mmHg. The British Hypertension Society (BHS) guidelines recommend antihypertensive treatment for sustained hypertension (160/100mmHg or above). Patients with systolic pressure 140-159mmHg or diastolic pressure 90-99mmHg, or both should be offered treatment if any of the following are present:

• target organ damage
• a complication of hypertension or diabetes
• an estimated 10 year risk of cardiovascular disease greater than 20% despite lifestyle advice.²

A recent Health Technology Assessment “Lowering blood pressure to prevent MI and stroke: a new preventive strategy” concluded that current guidelines limit the number of people who can receive treatment based on specific blood pressure levels.⁴ For example, a younger person with a high blood pressure will have lower risk of MI and stroke compared to an older person with average blood pressure. A recent meta-analysis investigating effects of blood pressure lowering regimens on major cardiovascular events based on different antihypertensive drug classes observed greater risk reductions in regimens which targeted lower blood pressure goals. No clear difference was demonstrated in the risk of CHD between regimens based on ACE inhibitors, beta blockers or diuretics.⁵ Choice of antihypertensive therapy depends on contraindications, indications for specific patient groups and cost-effectiveness. ALLHAT compared an ACE inhibitor, a calcium channel blocker and a thiazide diuretic in 33,357 patients with hypertension and one or more risk factors for CHD events.⁶ Evidence from ALLHAT supports the use of a thiazide as first line therapy in most patients. The draft NICE guidelines on management of hypertension in adults in primary care suggest drug therapy should begin with a thiazide or if not tolerated or ineffective a beta blocker.⁷

The BHS guidelines recommend a stepped approach to treatment using an AB/CD algorithm. This algorithm does not have a preferred first line antihypertensive, but states where there are no compelling indications then the least expensive drug (usually a thiazide diuretic) should be chosen. The algorithm is split into drugs that inhibit the renin-angiotensin system (angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor antagonists (AIIRAs) (A) or beta blockers (B)) and those that do not (calcium channel blockers (C) and diuretics (D))

• Step 1 in patients 55 years or above, or black patients is C or D
• Step 1 in patients aged 54 years or below and non-black is A (or B*)
• Step 2 is A (or B*) plus C or D.
• Step 3 if blood pressure remains uncontrolled is A (or B*) plus C and D.²

* Combination therapy involving B and D may induce more new onset diabetes compared with other combination therapies.

AIIRAs are recommended where people with microalbuminuria or proteinuria have a contraindication to ACE inhibitors⁷ or where cough is a limiting adverse effect with ACE inhibitors. ACE inhibitors remain the first choice in treatment of heart failure, although AIIRAs can be used as an alternative if patients are intolerant to ACE inhibitors. This is an unlicensed indication for AIIRAs and trial evidence does not support their routine use.⁸

Prescribing Data

More is spent on lipid regulating drugs than any other class of cardiovascular drug, prescribing and spending have both risen by around 250% over the last 5 years (6.4 million items and £184.7 million, quarter to December 2003). Chart 3 shows the year on year increase in prescribing of statins for strategic health authorities for the last three years. 96% of items for lipid regulating drugs are for statins (simvastatin 2.6 million items and atorvastatin 2.4 million items per quarter). Since the price reduction for simvastatin in December 2003 more was spent on atorvastatin (£76.8 million compared to £70.9 million quarter to December 2003). About 1.8 million people (over 3% of the population) are currently receiving statin therapy and this is potentially saving 6–7,000 lives a year as well as reducing the number of heart attacks.¹

Variation Between Strategic Health Authorities in Prescribing of Statins (Chart 3)

Diuretics are the most commonly prescribed cardiovascular drugs but only account for 3% of all cardiovascular cost. There were 8.9 million items for diuretics at a cost of £16.3 million (excluding diuretics in combination with other antihypertensive drugs), quarter to December 2003. Thiazides account for 54% of all diuretic items: bendroflumethiazide (bendrofluazide) is the most commonly prescribed (4.5 million items and £5.0 million). Furosemide (frusemide) is the most commonly prescribed loop diuretic (2.5 million items and £3.2 million). Co-amilofruse accounts for 65% of potassium sparing diuretics in combination (560,000 items, £2.3 million per quarter). Amiloride prescribing has fallen to 86,000 items, £222,000 per quarter. Spironolactone prescribing has grown by 330% over the last 5 years to 331,000 items, £1.4 million per quarter.

There were 6.4 million items for beta blockers, quarter to December 2003, costing £24.7 million. Atenolol is most frequently prescribed (4.2 million items, £6.0 million). Prescribing of renin-angiotensin system drugs has more than doubled in the last 5 years with cost increasing by 91% (7.6 million items, £122 million). ACE inhibitor prescribing has grown to 5.8 million items, costing £76.2 million per quarter. The most commonly prescribed ACE inhibitors are ramipril and lisinopril (2.0 million and 1.7 million items, costing £31.2 million and £18.2 million respectively, per quarter). AIIRAs account for 1.8 million items and £45.9 million per quarter. There are 4.9 million prescription items for calcium-channel blockers, costing £83.9 million per quarter. Amlodipine accounts for 39% of prescribing for calcium-channel blockers (1.9 million items, £43.3 million).

Prescribing of antiplatelet drugs has doubled in the last 5 years to 6.5 million items per quarter costing £31.3 million. Aspirin is still the most frequently prescribed (5.7 million items) followed by clopidogrel (0.5 million items), quarter to December 2003. However clopidogrel accounts for three quarters of all antiplatelet drugs cost (£23.1 million) compared to £4.8 million for aspirin.

REFERENCES

1. Department of Health. Winning the war on heart disease. The National Service Framework for coronary heart disease. Progress report 2004 www.dh.gov.uk/assetRoot/04/07/71/58/04077158.pdf
2. British Hypertension Society guidelines for hypertension management 2004: summary. BMJ 2004; 328: 634-640
3. British Heart Foundation. Statistics on smoking cessation service in England, April 2002 to March 2003
   www.heartstats.org/uploads/documents%5Csmoking2004.pdf
4. Law M, Wald N, Morris J. Lowering blood pressure to prevent myocardial infarction and stroke: a new preventive strategy. Health Technol Assess 2003; 7 (31)
5. Blood Pressure Lowering Treatment Trialists’ Collaboration. Effects of different blood-pressure-lowering-regimens on major cardiovascular events: results of prospectively-designed overviews of randomised trials. Lancet 2003; 362: 1527-1535
6. The ALLHAT Officers & Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic. JAMA 2003; 288: 2981-2997
7. NICE. National Clinical Guidelines for Type 2 Diabetes. Blood pressure management. www.nice.org.uk/pdf/bloodpressure_full_guideline.pdf
8. National Prescribing Centre. The place in therapy of angiotensin II receptor antagonists. MeReC Bulletin 2003; 13 (6)
9. Foster C, et al. Cardiovascular disorders. Primary prevention. Clin Evid 2003; 10: 173-175
10. Heart Protection Study Collaborative Group. MRC/BHF Heart protection study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet 2002; 360: 7-22
11. NICE. Appraisal Consultation Document. Clopidogrel and modified-release dipyridamole in the secondary prevention of occlusive vascular events. February 2004 www.nice.org.uk/article.asp?a=105159