By including hypertension among the clinical indicators the new contract should aid GPs in reducing strokes and coronary events, says Dr Alan Begg


Reducing cardiovascular risk is seen as a key clinical priority throughout the UK. An increase in blood pressure is incrementally associated with an increased risk of a stroke or a coronary event, with systolic BP being a more important determinant of that risk. There is extensive evidence that lowering raised BP reduces the patient’s cardiovascular risk.

Identifying and managing patients with raised BP rests principally with the general practitioner and the primary care team. With good reason therefore the management of established hypertension is included as one of the 10 disease categories covered by the clinical indicators of the new GMS contract (Table 1, below).

Table 1: Clinical indicators for hypertension
Disease/ indicator no Clinical indicator Points Qualifier Preferred Read code Exception reporting and suggested Read code Payment stages
BP 1 A register of patients with established hypertension 9   Hypertension G2% Reduce set denominators by: • No of hypertension patients refusing treatment 813N & XaIyC; • No of patients invited for review at least 3 times and who refused to attend in preceding 12 months; • No of patients unfit for review because of frailty, terminal illness or other relevant circumstances  
BP 2 % patients with hypertension and smoking status recorded 10 Record at least once Never smoked 1371
Ex-smoker 137L
Smoker 137R
Joined practice in previous 3 months 25-90%
BP 3 % patients with hypertension who smoke offered or referred for smoking cessation advice 10 Offer at least once Smoking cessation advice 8CAL Local specialist smoking cessation clinic not available 25-90%
BP 4 % patients with hypertension with BP recorded 20 Measured in past 9 months Examination of BP 246 Joined practice in previous 3 months 25-90%
BP 5 % patients with hypertension with BP 150/90 or less 56 Measured in past 9 months Numeric value Joined practice in previous 9 months; • On maximum tolerated doses of medication (or not tolerated) and BP level suboptimal; • ACE inhibitor contraindicated (8128), adverse reaction or allergy; • A2 antagonist contraindicated (812H), adverse reaction or allergy; • Beta blocker contraindicated, adverse reaction or allergy; • Calcium channel blocker contraindicated, adverse reaction or allergy; • Diuretic contraindicated, adverse reaction or allergy 25-70%

Clinical indicators for hypertension

Establishing the diagnosis – BP 1

In practical terms it is important to confirm whether the BP is consistently raised before making a diagnosis of hypertension. Appreciating the continuum of risk and taking other risk factors into account means that numerical definitions have reduced relevance (Box 1, below).

Box 1: Classification of blood pressure levels
  Systolic BP (mmHg) Diastolic BP (mmHg)
Optimal <120 <80
Normal 120-129 80-84
High normal 130-139 85-89
Grade 1 hypertension (mild) 140-159 90-99
Grade 2 hypertension (moderate) 160-179 100-109
Grade 3 hypertension (severe) >180 >110
Isolated systolic hypertension >140 <90

The clinical indicators are disease category centred, thus losing an opportunity to develop the current trend towards patient care based on the overall level of patient risk. It is not explicitly stated – although it is implied within the supporting documentation – that establishing a disease register for hypertension can be simplified by excluding those patients with raised BP who have pre-existing coronary heart disease, stroke or diabetes. These patients are at high cardiovascular risk, and indicators that set BP measurements and targets (CHD 5 and 6, Stroke 5 and 6 and Diabetes 11 and 12) are included separately within each disease category.

Peripheral arterial disease is not included as a specific disease category, so practices need to be aware that these patients have a high cardiovascular risk when following this advocated ‘primary prevention’ approach.

Measuring risk

Raised BP is an independent risk factor for stroke and CHD events. At present, the Joint British Societies Coronary Risk Prediction Chart based on Framingham data is the recommended means of measuring 10-year CHD event risk.1 This measurement correlates well with the total cardiovascular risk, which is more appropriate to raised blood pressure and is likely to be recommended when the current guidelines are updated. A more recent European approach is to use the risk based on total cardiovascular death customised to reflect the variable risk from country to country.2

Patients’ role in managing high blood pressure

Home monitoring: Home monitoring with electronic transmission of the results to the clinician may in the future assist in improving blood pressure control.

At present, using a validated device,3 home blood pressure monitoring can:

  • Be more reproducible
  • Give values on different days closer to daily life conditions
  • Remove the white coat effect if averaged over several days
  • Provide more information for a clinician’s therapeutic decision
  • Improve compliance

Home BP levels are, however, lower than those taken in the clinic by as much as 12/7 mmHg, so to avoid confusion only BP values recorded in the practice should be used to ascertain whether the audit standard has been achieved.

Lifestyle change: All patients with raised or high normal blood pressure (see Box 1 above) should be supported in making lifestyle changes to reduce both their blood pressure and their total cardiovascular risk.

The following measures will lower a patient’s blood pressure:

  • Weight reduction
  • Reducing salt intake
  • Moderating alcohol intake to 21 units for men (14 units for women)
  • Regular dynamic exercise tailored to the individual
  • Increased fruit and vegetable intake
  • Decreased intake of total and saturated fat.

Smoking cessation – BP 2 & 3

Stopping smoking is the most effective lifestyle measure to reduce cardiovascular risk in patients with hypertension. However, smoking does not have any independent effect on blood pressure and stopping smoking will not lower the patient’s blood pressure.4

Apart from the improvement in cardiovascular risk, stopping smoking can help improve the beneficial effect of certain antihypertensive agents. However, steps should be taken to ensure that smokers who stop do not put on weight as this can raise blood pressure.

Although there is no clear evidence or consensus on the ideal smoking cessation strategy, nicotine replacement therapy and bupropion are both safe to use to facilitate smoking cessation in patients with hypertension. 5

Target blood pressure – BP 5

In hypertensive patients less intensive treatment can lead to 20% more strokes and CHD events with the achieved blood pressure being a major determinant of outcome.

The only trial specifically designed to investigate optimal blood pressure targets unfortunately lacked the power to provide definitive evidence of that target.6 A lower BP does, however, lead to a lower number of cardiovascular events, but the currently accepted optimal blood pressure for those with hypertension is less than 140/85 mmHg.7

Choosing the British Hypertension Society (BHS) Audit Standard seems a reasonable first step in demonstrating a minimum standard of blood pressure control. Clinicians know how difficult it can be to reach this target, with a large proportion of patients requiring more than one antihypertensive agent to do so.

To meet the clinical indicator the achieved blood pressure can be 150/90 mmHg or less.

Case finding

All adults up to the age of 80 years should have their BP checked every 5 years. Practices should continue with an opportunistic approach to identifying patients with raised BP either at new patient registrations, routine consultations or when the patient attends for a specific reason such as influenza immunisation.

Population based screening initiatives such as National Blood Pressure Testing Week 8 supported by community organisations or community pharmacies are important to raise awareness and identify initially those with raised BP. Practices should continue to be responsible for assessment and management of these patients once they have been identified (see Box 2, Figure 1 and Box 3 below).

Box 2: Assessment of patients with hypertension
  • Full clinical history
  • Physical examination
  • Investigations
    • Urinalysis to exclude haematuria and proteinuria
    • Urea and electrolytes
    • Blood glucose
    • Total cholesterol:HDL cholesterol ratio
    • Electrocardiogram
  • Appropriate global risk assessment
Figure 1: Evaluation of raised blood pressure
Box 3: Measuring blood pressure
  • An appropriate device should be used
  • Patients should sit for several minutes in a quiet room before beginning
    measurements
  • Remove tight clothing and ensure the hand is relaxed
  • Most patients should remain seated with the arm at the level of the heart
  • Cuff bladder size should be adjusted for arm circumference
  • Deflate at 2 mm per second and measure to nearest 2 mmHg
  • Record diastolic at phase V (disappearance of sounds)
  • Take two measurements at each visit
  • Use standing BP at 1 and 5 minutes in elderly and patients with diabetes to exclude orthostatic hypertension

Models of care

Although there are clear benefits from lowering raised BP, the most recent data suggest only limited success in reducing BP, with only 39% of hypertensive adults reaching a target of 160/90 mmHg,9 a slightly higher level than the contract’s target of 150/90 mmHg.

Hypertension clinics have traditionally been run in primary care by specialist or practice nurses. No randomised controlled clinical trials have shown that any one professional group within primary care can deliver better BP control in patients without cardiovascular disease or diabetes.

Clinical tools such as computerised decision support systems have yet to prove their value in improving BP control.10

In order to improve BP control, all primary care team members need to adopt a consistent approach to encourage patient engagement. Measures include:

  • Giving a full explanation of the condition and the need, as appropriate, for treatment
  • Providing a clear treatment plan
  • Agreeing on target levels
  • Addressing misconceptions
  • Explaining the need for possible combination therapy
  • Considering the use of fixed dose combinations where appropriate.

Further reduction of cardiovascular risk

Current guidelines suggest that patients with a CHD risk greater than 30% should be prescribed a statin,11 although the thresholds are likely to be lowered on the basis of recent trial data which have shown that hypertensive patients without vascular disease and with three other cardiovascular risk factors will benefit from a statin.12

Patients will also benefit from aspirin 13 and that benefit outweighs the risk of harm if the 10-year risk is greater than 15% once the BP is lowered to less than 150/90 mmHg.14

Practice monitoring

The main components of a monitoring visit carried out by the PCT for this category will be to ensure that:

  • Patients with hypertension are fully evaluated
  • There is clarity over who is included in the register
  • Patients with established CHD, stroke and diabetes are not counted twice
  • Appropriate lifestyle advice, apart from smoking cessation, has been provided
  • Surgery blood pressures are, as far as possible, used
  • BP is recorded using a device with validated accuracy which is both properly maintained and calibrated
  • Full use is made of an appropriate skill mix, with practice team roles and competencies clearly defined.

By focusing on identifying patients with raised BP and ensuring that their BP level is lowered adequately, the primary care team, in partnership with their patients, can continue to play an essential role under the new contract in reducing strokes and CHD events.

References

  1. Joint British recommendations on prevention of coronary heart disease in clinical practice.British Cardiac Society, British Hyperlipidaemia Association, British Hypertension Society, endorsed by the British Diabetic Association. Heart 1998; 80(Suppl 2): S1-29.
  2. Conroy RM, Pyorala K, Fitzgerald AP et al; SCORE project group. Estimation of ten-year risk of fatal cardiovascular disease in Europe: the SCORE project. Eur Heart J 2003; 24(11): 987-1003.
  3. O’Brien E, Waeber B, Parati G et al. Blood pressure measuring devices: recommendations of the European Society of Hypertension.Br Med J 2001; 322: 531-6.
  4. Omvik P. How smoking affects blood pressure. Blood Press 1996; 5(2): 71-7. Review.
  5. Guidelines Committee.2003 European Society of Hypertension-European Society of Cardiology guidelines for the management of arterial hypertension. J Hypertens 2003; 21(6): 1011-53.
  6. Hansson L, Zanchetti A, Carruthers SG et al. Effects of intensive blood-pressure lowering and low-dose aspirin in patients with hypertension: principal results of the Hypertension Optimal Treatment (HOT) randomised trial. HOT Study Group. Lancet 1998; 351: 1755-62.
  7. Ramsay LE, Williams B, Johnston G et al. Guidelines for management of hypertension: report of the third working party of the British Hypertension Society. J Hum Hypertens 1999; 13: 569-92.
  8. The BPA National Blood Pressure Testing Week www.bpassoc.org.uk/campaigns/testing_week.htm
  9. Primatesta P, Brookes M, Poulter NR. Improved hypertension management and control: results from the health survey for England 1998. Hypertension 2001; 38: 827-32.
  10. Montgomery AA, Fahey T, Peters TJ, MacIntosh C, Sharp DJ. Evaluation of computer based clinical decision support system and risk chart for management of hypertension in primary care: randomised controlled trial. Br Med J 2000; 320: 686-90.
  11. Scottish Intercollegiate Guidelines Network. SIGN 40. Lipids and the primary prevention of coronary heart disease. Edinburgh: SIGN, 1999.
  12. Sever PS, Dahlof B, Poulter NR et al; ASCOT investigators. Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower-than-average cholesterol concentrations, in the Anglo-Scandinavian Cardiac Outcomes Trial ­ Lipid Lowering Arm (ASCOT-LLA): a multicentre randomised controlled trial. Lancet 2003; 361(9364): 1149-58.
  13. Antithrombotic Trialists’ Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. Br Med J 2002; 324: 71-86.
  14. Ritchie LD, Lowe GDO, Loke YK, et al.Aspirin for Primary Prevention: Consider ‘the risk’. Coronary Health Care 2001; 5(1): 45-50.

Guidelines in Practice, February 2004, Volume 7(2)
© 2004 MGP Ltd
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