Hypertension: One of the Most Frequently Diagnosed

Hypertension is one of the most prevalent conditions affecting people in the 21st century (F. Wilford Germino, May 2009), it is one of the most frequently diagnosed conditions in the western world and when left untreated can causes serious effects to a person’s quality of life. Hypertension can act as a catalyst towards many more serious and damaging conditions such as ischemia, heart disease, heart attacks, stroke, aortic aneurysms or even heart failure. Hypertension can develop due to a number of genetic and environmental factors it is in the vast majority of cases a combination of a number of differing factors such as family history, diet and lifestyle issues such as obesity that accumulatively lead to an elevated blood pressure which is the diagnostic requirement for hypertension.

The NHS website defines hypertension as ‘an abnormally high blood pressure of above 140/90mmHg or higher’ (NHS Oct 2018). The main issue with describing the symptoms associated with hypertension is that generally the symptoms are not noticeable and many people therefore live their life untreated and increase the risk of more serious issues such as a heart attack or stroke. The main indication of hypertension is associated with a progressive rise in blood pressure (NICE October 2016). The occurrence of hypertension in the present population is highlighted by the costs of primary care treatment, which is said within the NICE guidelines to have cost approximately £1,000,000,000 in drug expenditures alone. (NICE 2018)

When investigating the pathophysiology of hypertension there is still a lot of uncertainty about this (Beevers G, 2001), the NHS focuses upon risk factors for hypertension which are either modifiable or non-modifiable factors they include:

• Are over the age of 65 there is a vast increase in the chances of suffering from hypertension as aging and hypertension are associated with similar vascular structural changes such as the below mentioned atherosclerosis as well as the effects aging has on sympathetic neurological functioning. (Carethers M, Patricia L. November 1989)
• Have a high BMI and/or central obesity as this not only increases the about of pressure being put on your heart and blood vessels to work harder to reach the working muscles that are being put under a lot of strain from the extra weight load obesity has a strong link with both diabetes and atherosclerosis a condition that is prevalent in the western world where we have generally poor diets and therefore fatty deposits sit along the endothelium of our arteries causing a restriction in their diameter resulting in an increase in blood pressure against the arterial walls (Yaling Zhao et al. 2017)
• Have a family history of hypertension, this is a risk factor that is continually analysed and researched. Ranasinghe Priyanga and colleagues published an article which investigated the influence of family history of hypertension on disease prevalence. This study concluded that the prevalence of hypertension was significantly higher in those with a family history of hypertension. (Priyanga R, Dilini N, Jayawardena R and Katulanda P Jun 2015)
• Excessive sodium ingestion (Sung Kyu Ha, 2014)
• Are a regular smoker as smoking decreases the amount of oxygen being moved through gaseous exchange in the alveoli and thus a decreased amount of oxygen reaching the heart, in turn this causes an increase in blood pressure and heart rate as the heart is put under increased pressure by chemoreceptors in order to meet the demands of the muscles and thus this increased workload constantly leads to metabolic issues causing hypertension (Kannel WB 1990).

Figure 1 shows an overview of the process by with NICE has outlined a step by step guide to diagnosing hypertension. Stage 1 is using completed within a clinical setting by which a patient is either visiting the hospital or their GP and will undergo general health checks or may be attending for other reasons. After this at Stages 2-3, if hypertension is apparent the patient will then be asked to follow out one of the two below mentioned diagnostic tools to increase the accuracy reliability and validity of the diagnosis.

Within the most recently set guidelines by NICE from October 2016 if a patient has a clinical blood pressure of 140/90 mmHg or higher the provider should offer ambulatory blood pressure monitoring to confirm the diagnosis of hypertension this allows for an increase in reliability of a patient’s blood pressure reading’s as the increase in repeated testing over the course of 24 hours at intervals of at least two measurements per hour during waking hours a more reliable diagnosis can be granted. The provider then receives the measurements taken over the course of the day and uses the average value of a minimum of 14 measurements taken during the patient’s time of assessment to confirm a diagnosis. The reliability and the use of an average value from at least 14 results gives the ABPM diagnostic tool the grounds to be referred to as the Gold Standard Diagnostic test as it shows high levels of accuracy and reliability and a decreased risk of an anomaly having a major effect on diagnosis.

There is however another diagnostic tool used to diagnose hypertension, home blood pressure monitoring. This is a self-monitoring device in comparison to the automatic recording ABPM device this device is one of the two gold standard diagnostic tools for diagnosing hypertension and is recommended by major guidelines and the British and Irish Hypertension society. The procedure is very simple the patient is required to record two consecutive measurements at a minute interval twice daily, for at least 4 days but in most cases 7 days. The specialist will then remove the measurements taken on the first day and calculate an average value of all the outstanding measurements in order to approve the diagnosis of hypertension.

The current European guidelines for testing to diagnose and confirm the presence of hypertension are as follows, (Manica G, et al. July 2013)

Stage 1: Systolic 140 to 159mmHg and/or diastolic 90 to 99mmHg.

Stage 2: Systolic 160 to 179 mmHg and/or diastolic 100 to 109mmHg.

Stage 3: Systolic >/ 180mmHg and/or diastolic >/110mmHg

The NICE hypertension guidelines also stated that a practitioner must refer a patient to see a specialist the same day if they have a blood pressure reading of higher than 180/110 mmHg with signs of papilledema and/or retinal haemorrhage this form of hypertension is referred to as either stage 3 by the European guidelines or accelerated hypertension. (NICE 2018)

Figure 2 shows the care pathway established by the NICE Guidelines most recently updated in 2018, It is clear to see that the first stage of the care pathway is to implement lifestyle interventions as hypertension is a progressive increase of blood pressure the earlier treatment begins the greater the likelihood of reversibility or comfortable management. A study was completed by Dickson and colleagues funded by the NHS research department to investigate which lifestyle interventions had the most significant impacts on blood pressure. This studies results stated that there was a significant decrease in blood pressure with diet, exercise, relaxation, alcohol restriction, sodium restriction (Dickson H O. 2007). It is also advised by the NICE hypertension guidelines to offer advice and help to smokers to stop smoking (NICE 2018).

As shown in Figure 2, the next stage of the care pathway is to assess if the patient is fit and healthy enough to begin an antihypertensive drug treatment plan. The NICE guidelines show a set criterion for both people aged under 80 with stage one hypertension with a target organ damage, established cardiovascular disease, renal disease, diabetes or 10-year cardiovascular risk equivalent to 20% or greater and those people of any age suffering stage 2 hypertension. The British National Formulary outline the different forms of antihypertensive drugs as each treatment plan has differing contraindications. There are many different sub groups of anti-hypertensive drugs that all have the same goal shown as stage 4 of the care pathway to decrease the blood pressure to below 140/90 mmHg (Zanchetti A, 1984). These sub groups include vasodilator antihypertensive drugs such as Hydralazine hydrochloride which is given orally and is used more frequently in the case of resistant hypertension, centrally acting antihypertensive drugs such as Moxonidine which is used to manage and treat mild to moderate hypertension, adrenergic neurone blocking drugs which function by inhibiting the release of noradrenaline such as Guanethidine monosulphate and alpha-adrenoceptor blocking drugs the main being Prazosin which is characterised by its post-synaptic alpha blocking and ability to induce vasodilation (Weidmann, P.U 1997). During this stage of drug treatment ABPM and HBPM are used to monitor response to treatment (NICE 2018)

The last stage of the care pathway refers to patient education and adherence to the drug treatment. Within this stage of the pathway a patient is already undergoing a drug treatment plan and therefore the provider should offer advice to the patient in terms of compliance for example introduction the patient to the idea of accountability through completing a log book of their daily medication intake to ensure they are taking their medication as advised by the practitioner. This part of the care pathway has been greatly researched with various studies completed across the globe to find the best ways to increase patient adherence (Ashish Atreja et al. 2005) The main reason for the use of ABPM and/or HBPM is to decrease the impact of the ‘white collar effect’ (Dieterle T, Jan 2012) as many patients when in a hospital setting for a variety of different reasons such as past experiences, anxiety or stress may have a short term spike in blood pressure when being testing in a hospital setting which is the main reason behind the protocol that at least 3 readings must be completed and the closest to normal reading being accepted. A study completed by Daichi Shimbo and colleagues for the Journal of the American Society of Hypertension (Volume 10, Issue 3, March 2016 Pages 224-234) discussed the strengths of both ABPM and HBPM as they both record blood pressure under different conditions. ABPM assesses blood pressure during specific times of the day and night whereas HBPM assesses blood pressure as a specific time of the day or night over a longer period of time but the main strength that ABPM has over the use of a home blood pressure monitor is that it can assess the diurnal pattern of blood pressure particularly at night. On the other hand, HBPM devices are more widely available than ABPM devices and there is a greater association with patient compliance and tolerability and better-quality antihypertensive medication observance.

Recent studies suggest that in some circumstances HBPM devices are possibly not accurate to within 5mmHg (Ringrose S J et al. 2017). Therefore, it appears that ABPM would be the idealistic gold standard diagnostic test for hypertension but for its limiting factor of stock within the NHS and patient compliance as it could be very irritating to a patient and therefore cause stress which is a known lifestyle influencer of hypertension and therefore a patient may present a much higher blood pressure reading over this 24 hour period. Similarly, regarding patient compliance with HBPM as a diagnostic tool a patient would need to be consistent over the period of assessment to consistently record their own blood pressure twice daily in a seated relaxed position which is why the automatic recording of ambulatory blood pressure measurement appears to have an edge as the gold standard diagnostic tool. The main positive of having two very well researched and trusted methods of diagnosis allows for a patient to have a choice from the beginning of their assessment at the initial stages of diagnosis to the management and treatment monitoring phase of the care pathway and both methods could be used in conjunction with each other at different times during a patients treatment plan depending upon how they feel about their current treatment. This increases the patient’s satisfaction towards the NHS service and ensures an increase in patient compliance as they feel they have a say in their treatment to an extent.

Vasodilator antihypertensive drugs such as hydralazine hydrochloride and minoxidil have very potent hypotensive effects when combined with other drugs such as beta-blockers in patients with cardiac arrythmias may not be suited to these drugs as the main side effects of Hydralazine hydrochloride and Minoxidil when used in isolation are tachycardia and fluid retention because of these side effects it is compulsory to take these drugs in collaboration with beta blockers and a diuretic which is not ideal for patients who suffer from phobias of medication and anxiety as these treatment plans require a lot of differing drugs to be taken at once. As well as this Sitaxentan had to be withdrawn from use because the severe side effects such as severe hepatotoxicity were completely overwhelming the benefits of the treatment (NICE 2018). It is clear to see that the risk of vasodilator antihypertensive drugs tend to outweigh the positive treatment possibilities and therefore more research and alterations need to be completed to removing limiting factors from this form of treatment in comparison to alpha-adrenoceptor blocking drugs such as prazosin which rarely causes tachycardia but only carries the risk of a rapid decline in blood pressure after the initial treatment plan begins and therefore caution is required (Frans H.H Leenan 1987). These alpha blockers such as Doxazosin and terazosin can be used in conjunction with other anti-hypertensive drugs in the case of resistant hypertension and therefore I believe that they are an excellent choice for initial antihypertensive drug treatment plans. The variety of drugs readily available and present in the care pathway of hypertension is a very good factor as depending upon how a patient responses to a certain drug alterations can be made when required if a patient has other conditions or their quality of life is greatly affected by any of the side effects present with one of the specific drugs for example the previously mentioned hydralazine hydrochloride may be the ideal treatment plan for those who have fears of needles as this comes in a tablet form but for other patients the side effect such as headaches and nausea may have a huge effect on a patient who may regularly suffer from migraines. (Nature, 2009)

To conclude, the tangibility of this care pathway to suit the needs of an individual patient from the initial diagnostic stages continuously into the treatment and management of the condition is an excellent exemplar of the work of the NHS research and development sector. In order for this care pathway to improve in the future, the health service may need to make a judgement as to which of the two diagnostic tools is in fact the singular gold standard diagnostic tool for the diagnosis of hypertension and in regards to drug therapies a greater deal of research and alterations needs to be invested upon within the vasodilator antihypertensive drugs as they currently contraindicate with a lot of other common conditions and diseases which in turn limits their usage (Houston MC, Sep 1991)