What is the investigation for malignant hypertension (high blood pressure)?

From the Guidelines

Malignant hypertension investigation requires immediate and comprehensive evaluation due to its life-threatening nature, and the initial assessment should include a complete history and physical examination, focusing on symptoms of end-organ damage, as well as laboratory tests and imaging studies to assess kidney function, cardiac function, and retinal damage, as recommended by the European Heart Journal 1. The diagnosis of malignant hypertension is characterized by severe BP elevation (usually >200/120 mmHg) and advanced retinopathy, defined as the bilateral presence of flame-shaped haemorrhages, cotton wool spots, or papilloedema, and it is essential to identify the underlying cause of the condition, which can include renal parenchymal disease, renovascular disease, primary aldosteronism, pheochromocytoma, and medication-induced hypertension 1. Key aspects of the investigation include:

• Complete blood count, comprehensive metabolic panel, urinalysis, and urine protein-to-creatinine ratio to assess kidney function and damage
• Specific tests for secondary causes, such as plasma renin activity, aldosterone levels, metanephrines, and cortisol levels
• Imaging studies, including renal ultrasound, echocardiogram, and CT or MRI of the brain if neurological symptoms are present
• Fundoscopic examination to identify retinal hemorrhages, exudates, or papilledema (grade III or IV hypertensive retinopathy) The management of malignant hypertension should prioritize stabilizing blood pressure using intravenous medications like labetalol, nicardipine, or clevidipine in a monitored setting, while also identifying the underlying cause for long-term management, as recommended by the European Society of Hypertension and the European Society of Cardiology 1. It is crucial to note that the prognosis of malignant hypertension is extremely poor if left untreated, with 50% of individuals dying within 12 months, but with effective management, survival is better, and reflects not only improved blood pressure control but also good identification of secondary causes and more widely available services such as renal dialysis and transplantation 1.

From the FDA Drug Label

For patients with severe hypertension (e.g., accelerated or malignant hypertension), when temporary discontinuation of current antihypertensive therapy is not practical or desirable, or when prompt titration to more normotensive blood pressure levels is indicated, diuretic should be continued but other current antihypertensive medication stopped and captopril dosage promptly initiated at 25 mg bid or tid, under close medical supervision

The initial dose of captopril for investigating malignant hypertension is 25 mg bid or tid under close medical supervision.

• The dose may be increased every 24 hours or less until a satisfactory blood pressure response is obtained or the maximum dose of captopril is reached.
• A more potent diuretic, e.g., furosemide, may also be indicated.
• Beta-blockers may also be used in conjunction with captopril therapy 2

From the Research

Definition and Characteristics of Malignant Hypertension

• Malignant hypertension is defined by extreme blood pressure 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.
• It is characterized by pronounced target organ damage, including structural and functional cardiac abnormalities and renal insufficiency 4.
• The condition requires prompt and efficient treatment due to its severe impact on target organs 3.

Diagnosis and Treatment

• Diagnosis involves evaluating organ damage, especially that of the heart and brain, using tools such as ECG, echocardiography, and brain MRI 5.
• Treatment typically involves the use of antihypertensive agents, with blockers of the renin-angiotensin system being a cornerstone of treatment 5, 6.
• The decision of which drug to use depends on numerous factors, including clinical indications, pharmacokinetics, toxicity, and drug interactions 4.
• First-line treatment options include labetalol and nicardipine, with urapidil and nitroprusside serving as alternative medications 3.

Prognosis and Outcomes

• Malignant hypertension has a worse prognosis than other forms of hypertension, especially in black patients 5.
• Renal survival at 5 years was found to be 90.8% in one study, similar to other studies 5.
• The condition can cause severe damage to the brain, heart, kidneys, and eyes, even in the absence of symptoms 5.

Management and Prevention

• Early recognition and treatment are crucial in managing malignant hypertension 6.
• Prevention strategies involve addressing socio-demographic and genetic factors that contribute to the elevated risk of malignant hypertension 3.
• Hospitalization is often required for hypertensive emergencies, while hypertensive urgencies can typically be managed with oral antihypertensive therapy and outpatient care 7.