In Clinical Practice

Cardiovascular diseases General medicine
Volume 193 - Issue 2

Cardiovascular risk perception and evidence–practice gaps in Australian general practice

Author:  Peter J Radford

Med J Aust 2010; 193 (2): 127-128. || doi: 10.5694/j.1326-5377.2010.tb03823.x
Published online: 19 July 2010
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To the Editor: As a long-time resident of the “swamp of uncertainty” which is general practice — where specialists dare not go — I am accustomed to receiving guidelines and consensus statements from esteemed colleagues and friends who have taken to studying some specific part of the human condition. But these statements inevitably involve primary care, where general practitioners try to achieve balance.

Balance is hard to achieve. The “gastro-partialist” thinks that everyone should be on a proton-pump inhibitor. On the other hand, the “osteo-partialist” thinks no-one should be on a proton-pump inhibitor because they stop calcium absorption and double the risk of hip fracture after 10 years. I could go on.

However, here I wish to comment on Heeley and colleagues’ article on the perception and management of cardiovascular disease (CVD) risk in Australian primary care.1

Two of the authors are paid by Servier — the company which provided GPs with free automated blood pressure-measuring machines (ABPMs). A review in the American Journal of Cardiology concluded that no ABPMs were accurate enough to be recommended for replacing a manual sphygmomanometer,2 particularly in older people, in whom vessel stiffness leads to overestimation.3 In the study by Heeley et al, ABPMs were used by 90% of the GPs.

Australia’s Therapeutic guidelines: cardiovascular say that the blood pressure treatment target should be 140/90 mmHg for all patients.4 It quotes the Cochrane review, which states:

A sensitivity analysis in diabetic patients and in patients with chronic renal disease ... did not show a reduction in ... mortality and morbidity outcomes with lower targets as compared to standard targets.5

Heeley et al have used other guidelines.

Based on the data provided by Heeley et al, about 17% of the patients in their study were aged over 75 years. Risk calculators do not usually go beyond 74 years, but it appears that with all risk factors at optimum levels, a 75-year-old man still has greater than 15% 5-year risk of a cardiovascular event (ie, a high risk). Being 75 years old is risky! Trying to treat a 75-year-old man’s blood pressure is particularly risky because evidence suggests that there is a paradoxical increase in cardiovascular mortality in men aged over 75 years whose blood pressure is lowered by treatment.6

Heeley and colleagues also stated that “two thirds of patients at high risk of a first CVD event were not prescribed a combination of a [blood pressure]-lowering medication and a statin”. Considering the 17% of patients who were older than 75 years, although the PROSPER (Prospective Study of Pravastatin in the Elderly at Risk) trial showed a reduction in cardiovascular mortality within this age group, there was no reduction in overall mortality.7 So why would a GP treat such patients when overall mortality is not reduced?

I imagine that some GPs undertreat because they anticipate poor compliance, because uncorrectable factors are so great that pharmacological interventions will have a miniscule effect, or because the side effects of drug doses needed to achieve guideline targets will be problematic. Maybe they also feel that their ABPMs read a bit high! Balance is an unconscious compromise between real evidence and what is achievable. We need to consider the whole as well as the part if guidelines are to be clinically relevant.

Author

  • Peter J Radford1
  • 1. Benalla, VIC.

Correspondence: drdog@iinet.net.au

References

View this article on Wiley Online Library