Malignant arterial hypertension

Malignant arterial hypertension - severe arterial hypertension with edema of the nipple of the optic nerve or extensive exudates (often hemorrhages) on the fundus, early and rapidly increasing damage to the kidneys, heart, brain. Arterial pressure usually stably exceeds 220/130 mm Hg.

[1], [2], [3], [4], [5], [6], [7], [8]

Epidemiology

Malignant arterial hypertension, as a form of hypertension, is not observed often (up to 1% of patients). Primarily malignant hypertensive disease is now extremely rare (0.15-0.20% among all persons with hypertensive disease). Mostly male patients are ill at the age of up to 40 years, after 60 years the incidence is sharply reduced, and by the age of 70 the disease is rarely recorded.

[9], [10], [11], [12], [13], [14], [15], [16]

Causes of the malignant hypertension

Arterial hypertension of any nature (hypertension or symptomatic hypertension) can acquire features of malignancy in the development process. The most common causes of malignant hypertension are:

• parenchymal diseases of the kidneys (fast-progressive glomerulonephritis);
• terminal renal failure;
• stenosis of the renal artery;
• arterial hypertension in smokers.

In some cases, malignant arterial hypertension may develop with endocrine pathology (pheochromocytoma, Conn's syndrome, renin secreting tumors), in women late in pregnancy and / or in the early postpartum period. Such an evolution is mainly observed in untreated or inadequately treated patients.

In contrast to other forms of arterial hypertension, in which there is a gradual elastofibroplastic restructuring of arterioles, the cause of malignant hypertension is acute changes in the arterioles of the kidneys with the development of fibrinoid necrosis. In malignant arterial hypertension, renal arterioles are often completely obliterated as a result of intimal proliferation, smooth muscle hyperplasia and fibrin deposition in the necrotic vascular wall. These changes lead to a violation of local autoregulation of the blood flow and the development of total ischemia. In turn, kidney ischemia leads to the development of renal failure.

As a factor responsible for acute changes in blood vessels in malignant arterial hypertension, hormonal stress is considered, leading to an uncontrolled synthesis of vasoconstrictor hormones and manifested:

• a sharp increase in blood vasoconstrictor hormones (hormones of the renin-angiotensin-aldosterone system, pressor hormones of the endothelium, vasopressin, catecholamines, pressor fractions of prostaglandins, and so on);
• water-electrolyte disorders with the development of hyponatremia, hypovolemia and often hypokalemia;
• development of microangiopathies.

Often, malignant hypertension is accompanied by damage to erythrocytes by fibrin strands with the development of microangiopathic hemolytic anemia. At the same time, morphological changes in blood vessels with malignant arterial hypertension with adequate and permanent antihypertensive treatment are potentially reversible.

[17], [18], [19], [20], [21], [22], [23], [24]

Symptoms of the malignant hypertension

Malignant arterial hypertension is characterized by a sudden onset and rapid progression of all the symptoms of the disease. The appearance of patients is characteristic: the skin is pale, with an earthy tinge. Often there are symptoms of malignant hypertension, such as dyspeptic complaints, rapid weight loss right up to  cachexia. Arterial pressure is persistently maintained at a very high level (200-300 / 120-140 mm Hg). Tendency to increase pulse pressure; the circadian rhythm of arterial pressure changes (the periods of night decrease in arterial pressure disappear). Often develop hypertonic encephalopathy, transient disorders of cerebral circulation with the corresponding clinic.

The defeat of the heart usually proceeds according to the type of left ventricular failure, with frequent development of pulmonary edema. When echocardiographic research reveals signs of hypertrophy and dilatation of the left ventricle.

An important clinical and diagnostic criterion of malignant hypertension is considered to be changes in the fundus, manifested by hemorrhages, exudates, edema of the optic nerve disk. A sudden loss of vision is observed in one or both eyes, which develops as a result of hemorrhages or other changes in the retina.

Forms

At the present stage, malignant hypertension is considered as a form of hypertensive disease or symptomatic arterial hypertension, an independent nosological form of the disease, described for the first time by Folgard and Far in 1914 and studied in detail by E.M. Tareev in the middle of XX century.

[25], [26], [27], [28], [29], [30]

Diagnostics of the malignant hypertension

Laboratory diagnosis of malignant hypertension

Kidney damage is characterized by the development of proteinuria (nephrotic syndrome occurs rarely), a decrease in the relative density of urine, changes in urinary sediment (often erythrocyturia). With a decrease in blood pressure, the severity of the urinary syndrome decreases. Oliguria, increasing azotemia, anemia reflect the early and rapid development of terminal renal failure, although the wrinkling of the kidneys is detected only in some patients. Often, malignant hypertension develops acute renal failure.

Diagnosis of malignant hypertension involves the detection of  anemia, often with elements of hemolysis, erythrocyte fragmentation and reticulocytosis; coagulopathy by the type of disseminated vascular coagulation with the development of thrombocytopenia, the appearance of fibrin degradation products in the blood and urine; ESR is often increased. Most patients have a high plasma renin activity and an elevated aldosterone content.

[31], [32], [33], [34], [35], [36], [37], [38]

Treatment of the malignant hypertension

Malignant hypertension is considered an emergency. Initial treatment of malignant hypertension is a decrease in blood pressure within 2 days by 1/3 of the baseline, while the level of systolic blood pressure should not be reduced below 170 mm Hg, and the diastolic blood pressure is below 95-110 mm Hg. For this purpose, fast acting antihypertensive agents administered intravenously for several days are used. Further decrease in blood pressure should be done slowly (over the next few weeks) and carefully to avoid hypoperfusion of organs and further deterioration of their functions.

Treatment of malignant hypertension: drugs for intravenous administration

For intravenous administration, several drugs can be used.

Sodium nitroprusside is administered for a long time (3-6 days) at a rate of 0.2-8 μg / kg per minute with titration of the dose every 5 minutes. It is necessary to constantly and carefully monitor blood pressure and the speed of administration of the drug.

Nitroglycerin (injected at a rate of 5-200 mcg / min) is the drug of choice for the treatment of hypertension in conditions of myocardial infarction, unstable angina, with severe coronary and left ventricular failure.

Diazoxide is administered 50-150 mg intravenously struino, the total dose should not exceed 600 mg / day. The drug is continued for 4-12 hours. The drug can not be used if malignant hypertension is complicated by myocardial infarction or exfoliating aortic aneurysm.

Possible intravenous use of an ACE inhibitor enalapril in a dose of 0.625-1.25 mg every 6 hours. Dose is halved when the drug is combined with a diuretic or with severe renal failure. The drug is indicated in cases of severe heart failure; It can not be used in patients with bilateral stenosis of the renal arteries.

Labetolol, which has both alpha and beta adrenergic blocking activity, is administered as a bolus 20-40 mg every 20-30 minutes for 2-6 hours. The total dose should be 200-300 mg / day. During the introduction, bronchospasm or orthostatic hypotension may develop.

Sometimes verapamil is effective with intravenous jet injection at a dose of 5-10 mg. Fosemide inside or intravenously is used as natriuretic. Additionally, plasmapheresis and ultrafiltration can be used.

Treatment of malignant hypertension: drugs for oral administration

If this intensive treatment of malignant hypertension, which lasts 3-4 days, achieves the desired result, an attempt may be made to switch to oral medication, usually using at least three antihypertensive drugs of different groups, selecting doses to further lower the blood pressure slowly.

When prescribing antihypertensive drugs, it is necessary to clearly establish the cause of development of malignant arterial hypertension (renoparenchymatous, renovascular, malignant arterial hypertension due to endocrine pathology, ischemic kidney disease, etc.), the state of renal function, concomitant diseases in order to take into account the advantages and disadvantages of each of the groups of antihypertensive drugs and to determine the possibility of their combined application.

Forecast

It should be borne in mind that effective antihypertensive treatment of malignant hypertension determines the prognosis of patients with malignant hypertension. Survival of untreated patients within 1 year is only 20%, while with adequate treatment, 5-year survival rate exceeds 90%.

[39], [40], [41], [42], [43], [44], [45]