Carotid artery stenosis in patients with hypertension

Szczegóły: Nadrzędna kategoria: ROOT; Kategoria: Choroby rzadkie; Opublikowano: sobota, 29.02.2020, 16:09; Odsłony: 2478

Krystyna Knypl

Abstract

Hypertension is the most common and strongest risk factor for atherosclerosis, which is the cause of carotid artery stenosis. Women suffer from hypertension more often than men, but the frequency of organ complications is higher in men. Periodic assessment of a patient’s condition is important because carotid artery stenosis in many patients develops asymptomatic, not diagnosed early enough can cause stroke and permanent disability.

The high cost of stroke treatment, which is the most serious complication of carotid artery stenosis, can be reduced by promoting a Mediterranean diet.

Keywords

Carotid artery stenosis, hypertension, carotid endarterectomy, carotid stenting, Mediterranean diet.

Introduction

Hypertension, which prevalence is estimated to be 1.13 billion in the whole world, is the most common and strongest risk factor for atherosclerosis, which is the cause of carotid artery stenosis. The overall prevalence of hypertension in adults is 30−45%, becomes more frequent with age and in people aged > 60 years prevalence is of > 60% [1,2,3].

The combination of these two facts should direct the attention of every physician in checking clinical signs and the lumen of the carotid arteries in every patient with hypertension. This is important because carotid artery stenosis is asymptomatic for a long time.

Epidemiology

People’s life expectancy is constantly increasing, this fact causes changes in the demographic structure of patients who visit doctors’ offices. The number of people aged 65(+) in doctors’ offices with hypertension is constantly increasing and this phenomenon will continue to grow. Women suffer from hypertension more often than men, but the frequency of organ complications is higher in men.

The study carried out on 1,116 cohort members, (ages 66 to 93) of the Framingham Study shown that age, cigarette smoking, systolic blood pressure, and cholesterol were independently related to carotid atherosclerosis [4]. The prevalence of significant carotid stenosis in the investigated population was 7% in women and 9% in men. Risk factors such as oral contraceptives and hormone replacement therapy play a role in the occurrence of carotid arterial stenosis in women [5].

Risk factor control is a very important way to prevent stroke in patients with international carotid artery stenosis. The INTERSTROKE study showed that 10 potentially modifiable risk factors explained 90% of the risk of stroke [6].

The INTERSTROKE study evaluated assessed the following risk factors: history of hypertension, current smoking, waist-to-hip ratio; diet risk score, regular physical activity, diabetes mellitus, alcohol intake (more than 30 drinks per month or binge drinking), psychosocial stress, depression and apolipoproteins B/A1 ratio.

These risk factors were all significant for ischaemic stroke, whereas hypertension, smoking, waist-to-hip ratio, diet, and alcohol intake were significant risk factors for intracerebral hemorrhagic stroke.

Diagnosis of carotid artery stenosis

We have various methods at our disposal for diagnosing carotid artery stenosis – starting with the patient’s examination and auscultation of the arteries, after various additional examinations.

Auscultation of the murmur over the heart and arteries was introduced by an English physician James Hope (1801–1841), while the diagnostic tests were introduced in later years: angiography (1927), ultrasonocardiography (1955), phonocardiography (1965), magnetic resonance imaging (1971) computed tomography (1979) [7,8].

An important element of clinical assessment of patients with hypertension should be also periodically checking for orthostatic hypotonia, which is particularly common in diabetic patients. Gurevich A. et al. [9] observed orthostatic hypotonia in 25% of patients with severe carotid artery stenosis.

Patients with orthostatic hypotension have higher values of systolic blood pressure, longer duration of hypertension and their hypertension was uncontrolled more frequent than among patients without orthostatic hypotension [10].

The frequency of hypertension is extremely high among patients with carotid artery stenosis. Lukanova et al. [11] shown that hypertension was the most frequent of risk factors – in asymptomatic patients compared to the symptomatic patients was higher ( 97% v. 94%). In this group, dyslipidemia was diagnosed in 75% of patients and 75% of them smoked cigarettes.

Diabetes was in one-third of all patients but more frequently was diagnosed in the symptomatic group (41%). Among the investigated group 44% of patients had coronary artery disease and 47% peripheral arterial disease. Pharmacological treatment among this group was as follows: 54% of patients were on statin therapy, 88% – on antiplatelet drugs and 92% were on antihypertensive therapy.

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Hypertension treatment

Hypertension treatment is a difficult task for both the doctor and the patient. For the doctor, because success depends to a large extent on the patient, his motivation and discipline. For the patient – because he does not realize how much depends on him.

If we add to this the views that have been changing for decades on the value of blood pressure, which should be regarded as the norm, we will have a full picture of how difficult it is to treat hypertension.

The differences in definitions of what is hypertension and what is not, well illustrates the humorous saying known to hypertensiologists that a person with a pressure of 139/89 mmHg leaves Europe with a pressure that is qualified as high but still normal, and when he will land in the United States with the same pressure, he will be diagnosed as stage 1 hypertension.

In the age of globalization, this may be not only a funny joke but also a real problem when we meet our agent from a company selling travel health insurance.

There are different views not only on the definition of blood pressure but also on what values to lower blood pressure in older patients, and such patients are particularly at risk of developing carotid artery stenosis.

Many clinical studies have shown different benefits of treating hypertension, such as The VA Cooperative Study, The Australian National Blood Pressure Trial, The Systolic Hypertension in the Elderly Program, The Heart Outcomes Prevention Evaluation.

These studies, however, did not concern the treatment of hypertension in older people. This issue was examined just in the HYVET study, the results of which were published in 2008, and further results in 2013 [12]. The results HYVET trial provides evidence that antihypertensive treatment in persons 80 years of age or older is beneficial, earlier we didn’t have such scientific data.

Whereas the clinical trial SPRINT showed that targeting a systolic blood pressure of less than 120 mm Hg, as compared with less than 140 mm Hg, in patients at high risk for cardiovascular events but without diabetes resulted in lower rates of fatal and nonfatal major cardiovascular events and death from any cause [13].

Carotid stenosis treatment

Two treatment methods – endarterectomy and carotid artery stenting – are used for treating carotid artery stenosis [14]. Among 2502 patients with symptomatic or asymptomatic carotid stenosis (a follow-up period was 4 years), the risk of the stroke, myocardial infarction, or death did not differ significantly in the group undergoing carotid-artery stenting and the group undergoing carotid endarterectomy. The long term results concerning those patients group were presented later [15]. After 10 years follow up also did not show significant differences between carotid-artery stenting and carotid endarterectomy groups, as well as restenosis, which was infrequent in both groups.

These observations have shown long-term beneficial effects of treatment with carotid stenting or endarterectomy, which is important due to the fact of life expectancy, which is 15 years for men and 17 years for women for older the U.S. population [16].

Several other randomized trials comparing stenting with endarterectomy have been conducted and shown similar results of treatment [17, 18, 19, 20].

Diet and stroke prevention

High costs of stroke treatment estimated for 2010 as $ 73,7 billion in the US and 64,1 billion € in Europe should motivate to search for effective prevention methods. One such way of stroke prevention with scientifically proven effectiveness is the Mediterranean diet [21].

The high adherence to the Mediterranean diet reduces stroke risk and can modify the costs of its treatment and rehabilitation, therefore the dietetic prevention should be the number one polices in every country.

Conclusions

Hypertension is the main reason for visits to doctors’ offices around the world. This fact creates frequent and convenient conditions to control carotid arteries and thus prevent stroke. In the treatment of patients with hypertension, the condition of the carotid arteries should always be carefully monitored and risk factors controlled, paying attention to systolic blood pressure, which is a modifiable risk factor for carotid stenosis.

The Mediterranean diet should play an important role in the prevention of stroke, which is the most serious complication of carotid artery stenosis. Risk factor control is a very important way to prevent stroke in patients with international carotid artery stenosis.

Krystyna Knypl
specialist in internal medicine and hypertensiology

References

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