Malignant hypertension as a presenting symptom of Takayasu arteritis

A Case of Takayasu Arteritis with Thrombotic Microangiopathy Secondary to Malignant Hypertension Due to Bilateral Renal Artery Stenosis

A 20 year old woman presented with right arm pain. Pulses of right upper extremity were weak, acute phase reactants were elevated and MR angiography demonstrated total occlusion of subclavian artery and right axillary artery with collaterals. The diagnosis was Takayasu arteritis and she was treated with prednisolone, azathioprine and acetylsalicylic acid. During follow up, azathioprine was switched to methotrexate. Three years later, patient presented with elevated blood pressure. CT angiography demonstrated reduced calibration of the aorta and almost total occlusion of the lumen of proximal parts of left and right renal arteries. C-reactive protein was elevated. Steroid dose was increased, methotrexate was discontinued and IV tocilizumab and antihypertensive medications were initiated. One month later, she presented to emergency department with elevated blood pressure and blurred vision in the left eye. Fundoscopic examination revealed bilateral grade 3 hypertensive retinopathy and serous detachment of retina in the left eye. Laboratory results revealed normal CRP, elevated creatinine, elevated lactate dehydrogenase, thrombocytopenia, low hemoglobin and low haptoglobin. Peripheral blood smear revealed 2–3 schistocytes in every field. She was admitted to rheumatology department with the diagnosis of thrombotic microangiopathy secondary to malignant hypertension. IV tocilizumab was administered, and methylprednisolone was maintained at a dose of 20 mg/day. Despite treatment with maximum dose of six antihypertensive medications, her blood pressure was not controlled adequately and she became hypervolemic. After undergoing ultrafiltration, balloon dilation was performed in the left renal artery, and a stent was placed there. After stent placement, creatinine and platelet count normalized, hemoglobin increased and hypertension was controlled. In this case, malignant hypertension which was triggered by bilateral renal artery stenosis due to Takayasu arteritis had caused acute kidney injury and advanced stage hypertensive retinopathy. In addition, unlike other Takayasu arteritis cases with malignant hypertension, thrombotic microangiopathy was also detected.

[How to manage Takayasu arteritis?]

Thorough clinical and imaging assessment of the arterial tree when a diagnosis of Takayasu arteritis is established. Glucocorticoïd as intiation therapy. Immunosuppresive agent should be considered as adjunctive therapy if resistance or dependance to glucocorticoïd therapy. Supportive care, antihypertensive drugs, glucocorticoïd induced osteoporosis preventive therapy, tuberculosis screening should not be forgiven. Monitoring of therapy should be clinical and supported by biological markers and imaging. Reconstructive surgery should be performed in the quiescent phase of disease.

Clinical Features in the Management of Selected Hypertensive Emergencies

A hypertensive emergency is a clinical diagnosis that is appropriate when marked hypertension is associated with acute target-organ damage; in this setting, lowering of blood pressure (BP) is typically begun within hours of diagnosis. For hypertensive urgency with no acute target-organ damage, BP lowering may occur over hours to days. A hypertensive emergency may present with cardiac, renal, neurologic, hemorrhagic, or obstetric manifestations, but prompt recognition of the condition and institution of rapidly acting parenteral therapy to lower BP (typically in an intensive care unit) are widely recommended. For aortic dissection, the systolic BP target is lower than 120 mm Hg, to be achieved during the first 20 minutes using a beta-blocker (typically esmolol) and a vasodilator to reduce both shear stress on the aortic tear and the BP, respectively. Otherwise, sodium nitroprusside is the agent with the lowest acquisition cost and longest record of successful use in hypertensive emergencies; however, it is metabolized to toxic thiocyanate and cyanide. Other attractive agents include fenoldopam mesylate, nicardipine, and labetalol; in pregnant women, magnesium and nifedipine are used commonly. Most authors suggest a reduction in mean arterial pressure of approximately 10% during the first hour and a further 10% to 15% during the next 2 to 4 hours; hypoperfusion can result if the BP is lowered too suddenly or too far (eg, into the range of <140/90 mm Hg). Oral antihypertensive therapy can usually be instituted after 6 to 12 hours of parenteral therapy, and the patient moved out of the intensive care unit, when consideration should be given to screening for secondary causes of hypertension. Long-term follow-up to ensure adequate control of hypertension is necessary to prevent further target-organ damage and recurrence of another hypertensive emergency.