Date of issue: December 2011 Written by Sara Wilds & Kathryn Buchanan Prescribing Points A NEWSLETTER FOR ALL HEALTH CARE PROFESSIONALS IN OXFORDSHIRE, WRITTEN BY THE MEDICINES MANAGEMENT TEAM, OXFORDSHIRE PCT, JUBILEE HOUSE, OXFORD BUSINESS PARK SOUTH, OXFORD, OX4 2LH. VOLUME No: 20.12 Hypertension. This issue covers updated guidance in the management of hypertension in light of NICE CG 127 and recommendations of the Oxfordshire Area Prescribing Committee November 2011 Hypertension - Background The risk associated with increasing blood pressure is continuous, with each 2 mmhg rise in systolic blood pressure associated with a 7% increased risk of mortality from ischaemic heart disease and a 10% increased risk of mortality from stroke. Routine periodic screening for high blood pressure is now commonplace in the UK as part of National Service Frameworks for cardiovascular disease prevention. Consequently, the diagnosis, treatment and follow-up of people with hypertension is one of the most common interventions in primary care, accounting for approximately 12% of Primary Care consultation episodes and approximately 1billion in drug costs in 2006. NICE published Clinical Guideline 127 Hypertension in August 2011 The scope being the clinical management of primary hypertension in adults (aged 18 years and older) who may, or may not, have pre-existing cardiovascular disease. Revised Definitions Stage 1 hypertension Clinic blood pressure is 140/90 mmhg or higher and subsequent ambulatory blood pressure monitoring (ABPM) daytime average or home blood pressure monitoring (HBPM) average blood pressure is 135/85 mmhg or higher. Stage 2 hypertension Clinic blood pressure is 160/100 mmhg or higher and subsequent ABPM daytime average or HBPM average blood pressure is 150/95 mmhg or higher. Severe hypertension Clinic systolic blood pressure is 180 mmhg or higher or clinic diastolic blood pressure is 110 mmhg or higher. Key priorities for implementation are around the diagnosis of hypertension and the recommended use of Ambulatory Blood Pressure Monitoring (ABPM) Evidence reviewed by NICE concludes that ABPM is better than home BP monitoring, which is better than clinic BP readings, both in terms of clinical outcomes (CV endpoints) and in terms of costs (QALYs). The NICE Guideline Development Group noted that based on current data, home BP monitoring could not be considered equivalent to ABPM with regard to accuracy of diagnosis and emphasised that that ABPM is the preferred means of confirming or refuting the diagnosis of hypertension. Action required: Practices should review their protocols for diagnosis of hypertension and ensure access to Ambulatory Blood Pressure Monitors. 1
If the clinic blood pressure is 140/90mmHg or higher after 2-3 readings, offer ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension. HBPM may be an alternative if ABPM not tolerated When using ABPM to confirm a diagnosis, ensure that at least two measurements per hour are taken during the person s usual waking hours (for example, between 08:00 and 22:00). Use the average value of at least 14 measurements. When using HBPM to confirm a diagnosis, ensure that for each blood pressure recording, two consecutive measurements are taken, at least 1 minute apart and with the person seated and blood pressure is recorded twice daily, ideally in the morning and evening and blood pressure recording continues for at least 4 days, ideally for 7 days. Discard the measurements taken on the first day and use the average value of all the remaining measurements to confirm a diagnosis of hypertension In patients with severe hypertension (>180/110) DO NOT wait for results of ABPM, start antihypertensive treatment immediately. If hypertension is not diagnosed but there is evidence of target organ damage such as left ventricular hypertrophy, albuminuria or proteinuria, consider carrying out investigations for alternative causes of the target organ damage. If hypertension is not diagnosed, measure the person s clinic blood pressure at least every 5 years subsequently, and consider measuring it more frequently if the person s clinic blood pressure is close to 140/90 mmhg CBPM 140/90 mmhg & ABPM/HBPM 135/85 mmhg Stage 1 hypertension CBPM 160/100 mmhg & ABPM/HBPM 150/95 mmhg Stage 2 hypertension Care pathway If target organ damage present or 10- year cardiovascular risk > 20% If younger than 40 years Consider specialist referral Offer antihypertensive drug treatment Offer lifestyle interventions Offer patient education and interventions to support adherence to treatment Offer annual review of care to monitor blood pressure, provide support and discuss lifestyle, symptoms and medication For people identified as having a white-coat effect (a discrepancy of more than 20/10 mmhg between clinic and average daytime ABPM or average HBPM blood pressure measurements at the time of diagnosis) consider ABPM or HBPM as an adjunct to clinic blood pressure measurements to monitor the response to antihypertensive treatment with lifestyle modification or drugs. Use clinic blood pressure measurements to monitor the response to antihypertensive treatment with lifestyle modifications or drugs. Aim for a target clinic blood pressure below 140/90 mmhg in people aged under 80 years with treated hypertension. Aim for a target clinic blood pressure below 150/90 mmhg in people aged 80 years and over, with treated hypertension. Aiming for as low as is tolerated will reduce the risk of a cardiac event or stroke 2
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Changes to Drug Treatment Recommendations in line with NICE Give patients with isolated systolic hypertension (systolic BP 160 mmhg) the same treatment as patients with both raised systolic and diastolic BP. For patients > 80 years give the same treatment as patients aged 55 years. Take account of any co morbidity and concurrent drugs. For patients <55 remember ACE, ARBs are teratogenic and best avoided if there is the possibility of pregnancy ACEI and ARB If an ACEI is not tolerated because of cough, give a low cost ARB. Do NOT combine an ACEI with an ARB. Formulary choices:- ACE-I ramipril or lisinopril ARB losartan Calcium channel blocker CCBs are now the preferred treatment option at step 2 as they are cost effective. formulary choice:- amlodipine Diuretics Formulary choice for new patients indapamide 2.5mg once daily (or 1.5mg modified release once daily if side effects such as hypokalaemia). NB Bendroflumethiazide or hydrochlorothiazide are no longer the recommended thiazide-like diuretics for hypertension. For people already taking bendroflumethiazide or hydrochlorothiazide whose BP is stable; continue treatment. Additional treatment options at Step 4 Resistant hypertension (consider specialist advice) Spironolactone Doses of 25mg od may be a useful addition if serum potassium < 4.5mmol/L. Monitor for hyperkalaemia and hyponatraemia as well as renal function. Beta-blockers Beta-blockers are not recommended but can be used in step 1 for: younger people when an ACEI or ARB is contraindicated or not tolerated or, there is evidence of increased sympathetic drive or, in women of child-bearing potential. If a patient on a beta-blocker needs a second drug, add a CCB rather than a thiazide-like diuretic to reduce the risk of developing diabetes Formulary choice:- atenolol (bisoprolol if cardioselective preferred) Alpha-blockers Formulary choice:- doxazosin standard release NB. ALLHAT study showed an increased incidence of heart failure in patients taking doxazosin 5
Specialist Referral Refer the same day if: accelerated hypertension i.e. BP >180/110mm/Hg with signs of papilloedema and/or retinal haemorrhage, or suspected phaeochromocytoma. Consider referral in people with signs/symptoms suggesting a secondary cause of hypertension. For people aged under 40 years with stage 1 hypertension and no evidence of target organ damage, cardiovascular disease, renal disease or diabetes, consider seeking specialist evaluation of secondary causes of hypertension and a more detailed assessment of potential target organ damage. This is because 10-year cardiovascular risk assessments can underestimate the lifetime risk of cardiovascular events in these people Assessing target organ damage: updated recommendations For all people with hypertension offer to: initiatives to provide support and promote lifestyle change test urine for presence of protein take blood to measure glucose, electrolytes, creatinine, estimated glomerular filtration rate and lipid screen (fasting) examine fundi for hypertensive retinopathy arrange a 12-lead ECG CV Risk assessment Use a formal CV risk assessment (QRISK2) to discuss prognosis and management options. Assess CV risk in line with NICE CG67; Lipid modification Practice Priorities Review diagnosis and treatment pathways for people with hypertension in order to ensure in line with NICE CG 127 and APCO recommendations & ensure consistency within practice Ensure capacity to deliver ABPM to people who need it Consider use of potential 2011/12 Prescribing Incentive Scheme funds for purchase of ABPM through Oxfordshire wide bulk purchase option Ensure all blood pressure monitoring devices are properly validated, maintained and regularly calibrated 6