What is malignant hypertension?

From the Guidelines

Malignant hypertension is a hypertensive emergency characterized by severe blood pressure elevation (usually >200/120 mmHg) and advanced retinopathy, defined as the bilateral presence of flame-shaped haemorrhages, cotton wool spots, or papilloedema. This condition requires immediate emergency medical treatment to prevent serious complications like stroke, heart attack, kidney failure, or vision loss 1. Patients typically present with symptoms including severe headache, blurred vision, confusion, chest pain, shortness of breath, or seizures.

Key Characteristics

• Severe blood pressure elevation (usually >200/120 mmHg)
• Advanced retinopathy (bilateral presence of flame-shaped haemorrhages, cotton wool spots, or papilloedema)
• Requires immediate emergency medical treatment

Treatment

Treatment involves careful blood pressure reduction in a hospital setting, usually with intravenous medications like labetalol, nicardipine, or nitroprusside, with the goal of lowering blood pressure by no more than 25% in the first hour to avoid complications from too-rapid reduction 1. Once stabilized, patients require long-term management with oral antihypertensive medications such as ACE inhibitors, calcium channel blockers, diuretics, or beta-blockers, along with lifestyle modifications including sodium restriction, weight management, regular exercise, and stress reduction.

Management Considerations

• Activation of the renin–angiotensin system in patients with malignant hypertension is highly variable, making the BP-lowering response to renin–angiotensin system blockers unpredictable 1
• Large reductions in BP (exceeding a >50% decrease in mean arterial pressure) have been associated with ischaemic stroke and death
• Sodium nitroprusside, labetalol, nicardipine, and urapidil all appear to be safe and effective for the treatment of malignant hypertension

From the Research

Definition and Characteristics of Malignant Hypertension

• Malignant hypertension (MHT) is a hypertensive emergency with excessive blood pressure elevation and accelerated disease progression 2.
• It is characterized by acute microvascular damage and autoregulation failure affecting the retina, brain, heart, kidney, and vascular tree 2.
• MHT requires prompt and efficient treatment because it is the most severe kind of hypertension that affects target organs 3.
• The term "malignant" reflects the very poor prognosis for this condition if untreated 4.

Clinical Presentation and Diagnosis

• MHT is characterized by extreme BP elevation (systolic blood pressure above 200 mmHg and diastolic blood pressure above 130 mmHg) and acute microvascular damage affecting various organs, particularly the retinas, brain, and kidneys 3.
• Patients with malignant hypertension are characterized by pronounced target organ damage, including structural and functional cardiac abnormalities and renal insufficiency 5.
• The definition of MHT requires the presence of bilateral retinal hemorrhages or exudates, with or without papilledema, acute heart failure, and acute deterioration in renal function in severe hypertension 5.

Treatment and Management

• The management of patients with hypertensive emergencies, including MHT, must be ensured in an intensive care unit, and must include the parenteral administration of antihypertensive drugs and accurate blood pressure monitoring 6.
• The International Society of Hypertension 2020 and European Society of Cardiology/European Society of Hypertension 2018 recommendations suggest using labetalol and nicardipine as the first-line choice, with urapidil and nitroprusside serving as alternative medications 3.
• BP must be lowered within hours to mitigate patient risk, and both absolute BP levels and the pace of BP rise determine the risk of target-organ damage 2.

Risk Factors and Prevention

• Elevated risk of MHT has been linked to many socio-demographic and genetic factors 3.
• Limited access to treatment and poor adherence to anti-hypertensive therapy may contribute to the development of hypertensive emergencies 4.
• Nonadherence to the antihypertensive regimen remains the most common cause for MHT, although antiangiogenic and immunosuppressant therapy can also trigger hypertensive emergencies 2.