High blood pressure affects millions of people across the UK. But community pharmacists are ideally placed to help patients monitor this common condition, says Julie Ward
Key learning points
• High blood pressure contributed to around half of all heart attacks and strokes in the UK
• Medication to manage high blood pressure is not suitable for all patients, and some patients will need more than one medication to manage their condition
• More than half of patients are non-adherent to their medication, leading to increased risk of heart attack and stroke
Blood pressure is the pressure of blood in the arteries. Blood pressure readings consist of two numbers, usually shown as one on top of the other and measured in mmHg (millimetres of mercury). If the reading is 120/80mmHg, it may be referred to as ‘120 over 80’. The first (top) number represents the highest level the blood pressure reaches when the heart contracts – known as systolic pressure. The second (bottom) number represents the lowest level the blood pressure reaches as the heart relaxes between beats – known as diastolic pressure.
High blood pressure (hypertension) means that blood pressure is persistently above recommended levels. Unless stated otherwise, blood pressure should be below 140/90mmHg. Those with heart disease, diabetes or kidney disease should ideally have a reading below 130/80mmHg. People with high blood pressure are at increased risk of having a heart attack or stroke.
High blood pressure affects around 16 million people in the UK. An estimated seven million of those are undiagnosed, as there are rarely any symptoms. Some people may only find out they’ve got a problem when they have a heart attack or stroke. High blood pressure contributes to around half of all heart attacks and strokes in the UK.
Risk factors include being overweight, having too much salt in the diet, not doing enough physical activity, drinking too much alcohol and a having family history of high blood pressure. We also know that people from an Afro-Caribbean background and people living in deprived areas are at higher risk.
Maintaining a healthy weight, reducing salt intake, eating plenty of fruit and vegetables and being physically active all help to prevent high blood pressure. These are all important steps to take – even if people are also on medication to reduce their blood pressure.
How do people know if they have high blood pressure?
The only way to know if you have high blood pressure is to have it measured. In England, adults aged 40–74 can get a free NHS Health Check via their GP (and at some pharmacies). There are similar schemes in Northern Ireland, Scotland and Wales. Healthcare professionals should also do a blood pressure measurement on those under the age of 40 years with a risk of high blood pressure.
Blood Pressure UK and The Stroke Association run annual campaigns across the UK to carry out free blood pressure checks in a variety of community settings.
Diagnosing high blood pressure
In the general population, if blood pressure readings are consistently raised above 140/90mmHg, healthcare professionals
(in line with national guidelines) should instigate ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) to formally diagnose hypertension.
ABPM is the most accurate method for confirming a diagnosis of hypertension and its use should reduce unnecessary treatment in people who do not have true hypertension. ABPM has also been shown to be superior to other methods of multiple blood pressure measurement for predicting blood pressure-related clinical events. If a person is unable to tolerate ABPM, HBPM is a suitable alternative to confirm the diagnosis of hypertension.
Blood pressure medication
Blood pressure medication reduces the risk of heart attack and stroke in people with high blood pressure. But current UK guidance does not recommend medication for everyone. If blood pressure is only slightly raised, simple blood and urine tests (including checking cholesterol and blood sugar levels) will be carried out, an ECG will be performed and the person’s medical history will be reviewed.
What about side-effects?
Any drug can have side-effects. These are often mild but can mean a particular drug may need to be stopped. Healthcare professionals should explain this when blood pressure medication is first prescribed. Different drugs act in different ways so an alternative drug, or combination of drugs, may be required.
It can be hard to predict which drugs will work for each individual, but we know some are less effective in older people or those of Afro-Caribbean background. Most people will need more than one drug to control their blood pressure.
It is estimated that more than half of patients do not take their medications as prescribed. This contributes to poor blood pressure control and increased risk of stroke and heart attack.
Part of the problem is that the condition itself usually does not cause symptoms that act as a reminder to take medications. Switching to once-a-day tablets and advising patients to incorporate taking them into their daily routine can help. A dosette box (pill box with compartments for each day, and times of the day) may help patients adhere to their medication. These are available at most pharmacies, some supermarkets and some GP surgeries.
Blood pressure research that is changing current practice
One of the most recent important research trials is the BHF-funded PATHWAY-2 study. which is looking at the best drugs for people with resistant hypertension. This study compared drugs to identify the best fourth-line medication to use in patients whose blood pressure was not controlled, despite already taking three drugs. It demonstrated that a relatively old drug called spironolactone was better than other drugs tested in the trial.
Although spironolactone was already recommended as a possible option for resistant hypertension in NICE blood pressure guidelines, the results of PATHWAY-2 will hopefully improve blood pressure control in this challenging patient group.
The BHF is funding numerous research projects, including one looking at the best time to take medication and another looking at how genes could influence blood pressure. Over the past seven years, the British Heart Foundation has invested £35–40m in research on blood pressure.
If the public are interested in taking part in clinical trials like these, they should visit the UK Clinical Trials Gateway website.
Julie Ward is senior cardiac nurse at the British Heart Foundation