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How I...implemented hypertension algorithms

Dr John Cannon shows how he achieved good blood pressure control in his practice, way above targets

My practice has long recognised the importance of good blood pressure control. I recently drafted the first Suffolk county guidelines for diagnosis and management of hypertension in primary care. The reports I examined revealed poor implementation of evidence-based lifestyle and pharmacotherapeutic interventions over a number of years. Also, nGMS recognised the importance of hypertension control and planned to reward good quality care with specified points.

The large trials revealed that 75 per cent of patients need two, three or four different treatment types to control blood pressure to target and yet a large percentage of our patients receive monotherapy.

Of UK patients on combination therapy, the most common was a ß-blocker/thiazide seen often in our own practice.

What we did

We decided to follow BHS IV guidance, later largely adopted by NICE. We prioritised patients on atenolol/chlortalidone (our only ß-blocker/thiazide combination) with a systolic BP >150mmHg and/or diastolic BP >90mmHg, who lacked a diagnosis of CHD/ CHF. Our search revealed 51 patients who fitted the bill. We invited them to attend a routine appointment as recent inspection of our hypertensive patients had shown they were not managed to the newest goals and that their treatment might be improved.

These letters were staggered over eight weeks so only six or seven extra appointments per week were needed. I saw most of these patients and explained the rationale for the change. Some were enthusiastic and had read about the debate in the newspapers, while others were predictably resistant to or nervous of the plans. My colleagues were all aware and supportive of the venture and helped with patients' concerns.

We also addressed other CVD risk factors, giving lifestyle advice and modifying or adding other evidence-based interventions such as aspirin (with blood pressure control to <150 0mmhg),="" and="" statins="" as="" per="" jbs.="">

We knew that some of these patients could be harbouring as yet unknown CHD/CHF controlled or masked by the

ß-blockers taken for their putative uncomplicated hypertension. This was explained in preparation for the cross-tapering of

ß-blockers with ACE inhibitors (or ARBs if ACE inhibitors were poorly tolerated).

The thiazide was changed to a calcium channel blocker or indapamide (a thiazide-like diuretic with few reported metabolic side-effects and evidence to support its value in LVH regression and reduction of microalbuminuria). This was done to mirror the BHS IV guidelines and ASCOT-BPLA trial and in fact presaged the ACD approach of the newest NICE guidelines.

The patients' transition

Patients were forewarned of the likelihood of a faster heartbeat or possible palpitations, the possibility of angina being exposed and why, and the fact that they might experience some palpable benefits in terms of less fatigue, reduced impotence and warmer peripheries.

Patients were encouraged to phone me with any concerns during this transition period. I arranged to see them after six to eight weeks to recheck their blood pressure and had renal function tests performed four weeks after the changeover was started so that they had a reasonable exposure to ACE inhibitor or ARB treatment.

I received only three phone calls: two regarding an increased heart rate with occasional palpitations and one with increased apprehension and anxiety.

The next step was to find all other hypertensive patients with a latest blood pressure >150/90mmHg recorded in the past 12 months and offer them an appointment to review blood pressure.

I prioritised those with the highest blood pressure taken the longest time ago. The ACD approach was used with fourth-line

ß-blocker/spironolactone/a-blocker therapy as per BHS IV and NICE. Comorbidities often guided the choice of fourth-line agent if needed, for example prostatism for a-blockade; asthma/COPD removes ß-blocker from choice, and so on. This also afforded the

opportunity to readdress lifestyle, update appropriate investigations and consider managing other CV risk factors more comprehensively.

What we achieved

We had already achieved good control of uncomplicated hypertensives to a standard of <150 0mmhg="" at="" 70.3="" per="" cent="" in="" the="" first="" qof="" audit="" and="" had="" similarly="" good="" figures="" for="" control="" of="" our="" patients="" with="" chd,="" stroke="" and="" diabetes="" by="" following="" bhs="" iii="" advice.="" by="" implementing="" bhs="" iv="" and="" new="" nice="" guidelines,="" we="" exceeded="" the="" 70="" per="" cent="" target="" to="" attain="" full="" points="" for="" chd/stroke/hypertension="" by="" 23.5="" per="" cent,="" 18.7="" per="" cent="" and="" 8.2="" per="" cent="" respectively.="" we="" exceeded="" the="" target="" for="" diabetic="" hypertensive="" patients="" (55="" per="" cent="" at=""><145 5mmhg="" to="" attain="" full="" points)="" by="" a="" mammoth="" 24.1="" per="">

This may sound a large workload but was relatively easily absorbed into usual working practices. Exceeding targets will stand us in good stead for the future as GMS thresholds are likely to rise exponentially. More importantly, sub-optimally controlled hypertension is a major risk factor for the development or exacerbation of CHD, stroke, heart failure, CKD, retinopathy and diabetes and our patients will benefit most by our implementing these guidelines rigorously.

Following BHS IV/NICE guidance is simple using lifestyle advice coupled with the ACD therapeutic format. Our practice nurses are better than GPs at implementing such

algorithms so this area could be easily

devolved to our specialist practice nurses and nurse practitioners with appropriate training. This is likely to further improve our target attainment.

John Cannon is a GP in Ixworth, Suffolk. He is founder member of the Suffolk Cardiovascular Consensus Group, CHD lead and medicines management lead for Suffolk West PCT

Competing interests Dr Cannon has given lectures on hypertension sponsored by Sanofi-Aventis, Daiichi Sankyo, AZ and Servier

BHS iv guidance...

... and why we decided to follow it

• BHS IV (2004) had elegantly summarised a therapeutic algorithm based on renin, producing the well-documented A(B)CD approach. Even

in BHS III (B) was to be avoided in patients at risk of diabetes mellitus, especially in combination with a thiazide diuretic.

• BHS IV targets were = 140/85mmHg for uncomplicated hypertensive patients and =130/80mmHg for those with diabetes mellitus or target organ damage, whereas NICE and nGMS targets were higher.

• We felt that BHS IV held greater credence in view of the Framingham data showing a two- to eight-fold increased relative risk of CVD within 'normal' blood pressures of 140/90mmHg to 120/80mmHg.

• Also, attaining the BHS IV targets would tend to future-proof us if nGMS moved the goalposts.

• NICE changed its management algorithm to resemble that of BHS IV after ASCOT-BPLA and other studies.

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