The UHTA at the Hospital Ruber Internacional is headed by Dr Delgado Lillo. It is a multidisciplinary unit in collaboration with Internal Medicine, Cardiology, Conventional Radiology and Interventional Vascular Radiology, Nuclear Medicine, Endocrinology, Neurology, Gynaecology and Obstetrics.
Protocols are used to study patients with AHT in order to devise an etiological diagnosis, assessing the damage produced and the associated cardiovascular risk factors in order to apply the most appropriate treatment.
This is done using the most modern diagnostic and therapeutic methods, including all the techniques of interventional radiology, and incorporating radiofrequency denervation of the renal arteries.
Arterial Hypertension (AHT) is defined as blood pressure higher than 140/90.
It is estimated that more than 35% of Spain's adult population is hypertensive, a number that rises to 40% in intermediate ages and 60% among the population over 65 years of age. Of these, only 65% are identified and only 25% are properly diagnosed and monitored. This leads us to conclude that there are many people at high risk of suffering the devastating consequences of AHT.
AHT affects the arteries and organs with high degrees of vascularisation, such as the heart, central nervous system and kidneys.
Given how deaths or disabilities due to vascular damage in these organs are at the forefront of statistics in developed countries, there is no doubt that the fight against AHT is more than justified.
AHT is currently classified as follows:
Definition of arterial hypertension by the American College of Cardiology/American Heart Association (ACC/AHA) 2017
NORMAL ARTERIAL TENSION Systolic < 120 Diastolic < 80
HIGH ARTERIAL TENSION Systolic between 120-129 Diastolic < 80
Systolic > 140
Diastolic > 90
ISOLATED ARTERIAL HYPERTENSION Systolic ³ 130 Diastolic < 80
Consequences of AHT
How does Arterial Hypertension produce damage?
The increased pressure inside the arteries affects the walls, causing them to harden. This expedites arteriosclerosis, dilations and promotes the formation of blood clots. This affects the organs that receive the highest blood flow: the heart, central nervous system and kidneys.
The heart is affected in two ways: by damaging the arteries that supply it (coronary arteries) and by thickening and enlarging the left ventricle, which has to develop to overcome the resistance of the enlarged peripheral arteries. Over certain limits, coronary heart disease appears, leading to heart attacks, arrhythmias and heart failure, which cause a large number of deaths annually.
The most important damage to the central nervous system involves the large vessels that supply it. These are called acute cerebrovascular accidents (ACVA). When a rupture occurs, the result is cerebral haemorrhaging (20% of cases) and a lack of flow due to a blockage (ischaemia), causing a stroke (80%). The consequences range from transient vascular injuries (transient ischaemic attack, TIA) with no neurological consequences, to major debilitating and irreversible neurological injuries, and even death, all of which entail an immense social and economic cost. In addition, the central nervous system is susceptible to another type of injury that occurs when the small vessels that supply them are under high pressure for sustained periods of time. This leads to cases of progressive vascular dementia.
Kidney damage from AHT begins with small failures in one of the many kidney functions (uric acid retention, for example) and can progress all the way up to "nephroangiosclerosis" or renal sclerosis, which leads to the patient requiring dialysis and a kidney transplant. In Spain, there are more than 7500 people undergoing dialysis because they did not have their arterial tension diagnosed and controlled. They account for 34% of the patients who are in dialysis, though this percentage rises to 70% among those over 65 years old. This has turned Arterial Hypertension into the second leading cause, after diabetes mellitus, of advanced chronic renal insufficiency, and this is a cause that is largely avoidable.
In light of the above, and considering how vascular-related deaths are among the leading causes of mortality in developed countries, there is no doubt that the fight against ARTERIAL HYPERTENSION is more than justified.
How is Arterial Tension measured?
Arterial Tension is measured using a sphygmomanometer, which consists of an instrument that has a bracelet or cuff that squeezes the arm with a pneumatic mechanism attached to a pressure gauge that indicates the pressure in millimetres of mercury (mmHg).
There are two methods:
- Korotkoff acoustic system
- Oscillometric system
The first one requires the use of a phonendoscope, or a microphone, which can be used to hear the beats. When they start, as the inflation pressure is released, the systolic blood pressure (or maximum) is determined, and once the beats are no longer heard, this yields the diastolic blood pressure (or minimum). They used to have a column of mercury, but current regulations prohibit their use because of the toxicity of mercury.
The oscillometric method detects changes in the vibrations produced by the heart tones when the arteries in the arm are compressed. This is the method used in an automatic sphygmomanometer.
It is important that the cuff that goes around the arm be suitably sized to the patient. A wrist sphygmomanometer can be used in young people who are not obese.
Ways to measure blood pressure
The most common way to have your blood pressure checked is at the doctor's office. This visit often creates an emotional response in the patient that makes the pressure somewhat higher than normal, which can sometimes lead to a false high blood pressure reading, the so-called "white coat syndrome".In these cases, it is best to resort to self-measured blood pressure (SMBP) using a home kit under suitable conditions in order to properly diagnose AHT.
The measurement must be carried out with the appropriate cuff and without rushing. Readings must not be taken just after waking up or eating, but 2-3 hours afterward. The person should spend about ten minutes sitting and relaxing, without smoking (of course) or drinking stimulants such as coffee. An initial reading is taken, followed after approximately 3 minutes by a second reading, which is the one we will use to make the determination.
In certain situations, there will be doubts as to the blood pressure figures or problems adjusting the medication. In these cases, we will resort to Ambulatory Blood Pressure Monitoring (ABPM) also called "BPM Holter".
It has a cuff that goes around the arm for 24 hours, attached to a recorder and a portable automatic inflation system, which can be used to schedule readings throughout the day and night. It provides information on the patient's AT during periods of rest and activity, awake and asleep, which yields complete information for diagnosing and adjusting the treatment.
Resistant Hypertension (RHT)
RHT is the name given to AHT that remains high despite following the correct medical treatment with three drugs from the different therapeutic groups, including diuretics, at the maximum doses or the maximum doses tolerated by the patient.
The most common causes of RHT are:
- Advanced age
- Excessive salt intake
- Chronic kidney failure
- Diabetes Mellitus
- Obstructive sleep apnea
All of these are related to an increase in the activity of the sympathetic nervous system.
From the point of view of cardiovascular risk, we know that a small drop in blood pressure significantly decreases the risk of death due to an acute stroke and the risk of death due to coronary heart disease. This is why patients with RHT are treated by the Arterial Hypertension Unit as high-risk patients.
Treating RHT with Radiofrequency Renal Denervation
This is a technique for treating RHT that is used in patients whose blood pressure cannot be controlled using three drugs at the appropriate doses or at the maximum tolerated doses, which puts them at high cardiovascular risk.
The sympathetic nervous system can be blocked using specific drugs (ganglion blockers), but they are poorly tolerated and have many side effects, which decreases therapeutic compliance.
At the Hospital Ruber Internacional, we are pioneers in the development of radiofrequency renal denervation techniques.
It is a minimally invasive procedure that relies on the same approach to renal arteries that is used for arteriograms. Dr Zubicoa Ezpeleta, a highly experienced interventional vascular radiologist on our staff, performs this procedure.
It is done under sedation and on an out-patient basis, meaning the patient spends a few hours in the Day Hospital for treatment and is discharged in the afternoon.
A catheter is inserted into the renal arteries through a percutaneous puncture of the femoral artery. The radiofrequency catheter is then inserted to the distal end of both renal arteries and a low-intensity radiofrequency (up to 8 watts) is emitted for two minutes in each area to be treated, without exceeding a temperature of 60°.
This treatment is suitable for patients who have been previously studied and screened. Two-year data show very good results, with AT being brought under control in 84% of the patients treated.
In published studies involving large series of patients, there have been no serious complications related to the technique, only minor incidents that were immediately treated.
Furthermore, there have been no negative side effects from the treatment.