New guidelines on cardiovascular disease fail to consider the real world of general practice, says Dr Hugh Bethell

For many years I have moaned about the lack of consensus and nationally applicable guidelines on the management of coronary artery disease in general practice. Although there are plenty of guidelines on this practice area – mostly set up by local groups for their own local use – none have the support of the majority of GPs and can be applied uniformly across the country.

The British Cardiac Society has now attempted to correct this deficit, in the 'Joint British recommendations on prevention of coronary heart disease in clinical practice'.1 This document is a joint undertaking by the British (ardiac Society, the British Hyper-lipidaemia Association and the British Hypertension Society, 'endorsed by the British Diabetic Association'. It contains, in great detail and full justification, the treatment of high blood pressure and raised lipid levels.

These guidelines are mainly for use in general practice, but GPs are notably absent from the list of authors. One example of a failure to consider the real world of general practice is the use of a new set of risk tables to determine who should receive lipid lowering drugs for primary prevention. The lipid measurement used is the ratio of serum total cholesterol to HDL cholesterol. In many parts of the UK, however, it is not possible to get serum HDL measured routinely.

An example of the lack of common sense in the primary prevention section is highlighted in a recent short paper which points out that 85% of patients qualifying for guideline driven statin prescription do so because they smoke cigarettes.2 Is statin prescription really the correct treatment for nicotine addiction?

One blessing of the Joint British recommendations is the pragmatic approach to the diagnosis of hypertension requiring drug treatment (>160/100mmHg) – something sadly missing from the recently published '1999 WHO-International Society of Hypertension Guidelines for the Management of Hypertension'.3

These guidelines, again apparently formulated without the benefit of GP input (what proportion of hypertensives is treated outside general practice?), define hypertension as a blood pressure of 140/90mmHg, with a target of <130/85mmHg after treatment (the Joint British recommendations do not suggest a target).

A formidable protocol for the evaluation of these patients is outlined. No consideration is given to either the numbers needed to treat for unit benefit for the new targets, or the enormous amount of resources in both doctor and nurse time and drug costs, which will be consumed.

I estimate that more than half our patients would qualify for repeated observation and maybe treatment if we were to follow these guidelines. Even if the case were strongly made, would we really wish to give drugs to such a large proportion of our practice list and would they all consent to be converted to patients?

If guidelines for national and international use are to have any credibility they must be consistent with each other and realistic and their writing must involve those who will be expected to implement them.

I like the case study quoted recently.4 Guidelines based on national recommendations were developed for the management of dyspepsia in a health district. It was estimated that applying these guidelines would increase the number of endoscopies threefold. The article concluded: '... the recommendations were generally – and quite rationally – ignored'.

  1. Wood DI, Durrington P, Poulter N et al. Heart 1998; 80: Suppl 2.
  2. Muir J, Fuller A, Lancaster T. Br J Gen Pract 1999; 49: 217-18.
  3. Guidelines Subcommittee. J Hypertens 1999; 11: 905-l8.
  4. Haycox A, Bagust A, Walley T. BMJ 1999; 318: 391-3.

Guidelines in Practice, May 1999, Volume 2
© 1999 MGP Ltd
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