### Date : 2024-11-03 20:43 ### Topic : Takayasu's arteritis #cardiology ---- **Takayasu's arteritis** (TA) is a rare, chronic inflammatory disease that primarily affects the **large arteries**, especially the **aorta** and its major branches. It causes **inflammation of the vessel walls** (vasculitis), leading to thickening, narrowing (stenosis), and, in some cases, aneurysms of the affected arteries. This condition is also known as "pulseless disease" due to the weakened or absent pulses in the arms or legs that can result from arterial narrowing. ### Pathophysiology The exact cause of Takayasu's arteritis is unknown, but it is believed to involve an **autoimmune mechanism** where the immune system attacks the blood vessel walls. The disease primarily affects the **aorta** and its main branches, as well as the **pulmonary arteries** in some cases. 1. **Inflammation of the Arterial Wall**: - The inflammation starts in the **intima** (inner layer of the artery) and progresses to the **media** and **adventitia** (outer layers). - This inflammation leads to **thickening** of the arterial wall, narrowing the vessel lumen and reducing blood flow. 2. **Granulomatous Inflammation**: - A hallmark of Takayasu’s arteritis is **granulomatous inflammation**, where immune cells form clusters within the vessel wall. This inflammation is similar to other types of vasculitis, like giant cell arteritis. 3. **Fibrosis and Stenosis**: - Chronic inflammation results in **fibrosis** (scarring) and narrowing (stenosis) of the arteries. - This can lead to reduced blood supply to organs and tissues, causing ischemia. 4. **Aneurysm Formation**: - In some cases, the vessel wall weakens due to inflammation, leading to dilation or aneurysm formation, which can increase the risk of rupture. ### Epidemiology and Risk Factors - **Age**: Most commonly affects young adults, particularly those aged 10 to 40 years. - **Gender**: Predominantly affects females, with a higher prevalence in Asian women. - **Geographic Distribution**: It is more common in Asian countries, but cases are reported worldwide. ### Symptoms and Clinical Presentation The symptoms of Takayasu’s arteritis vary depending on which arteries are affected and the stage of the disease. The disease is often divided into two phases: an early "systemic phase" and a later "occlusive phase." 1. **Systemic (Early) Phase**: - This phase involves nonspecific symptoms due to systemic inflammation and may resemble a flu-like illness. - Common symptoms include: - **Fever** - **Fatigue** - **Weight Loss** - **Night Sweats** - **Arthralgia** (joint pain) - In this early phase, the disease is often difficult to diagnose as these symptoms are nonspecific. 2. **Occlusive (Late) Phase**: - As the disease progresses, inflammation leads to narrowing or occlusion (blockage) of major arteries. - Symptoms in this phase depend on which arteries are affected: - **Upper Limb Claudication**: Pain and fatigue in the arms, especially with activity, due to reduced blood flow. - **Weak or Absent Pulses**: Common in the arms, which has led to the nickname "pulseless disease." - **Blood Pressure Discrepancy**: Blood pressure may be significantly lower in one arm or leg compared to the other due to vascular obstruction. - **Carotidynia**: Pain over the carotid arteries. - **Headaches and Dizziness**: Due to reduced blood flow to the brain. - **Visual Disturbances**: If the arteries supplying the eyes are affected. - **Chest Pain or Dyspnea**: Can occur if the coronary arteries or pulmonary arteries are involved. - **Hypertension**: Due to renal artery stenosis (narrowing of the arteries to the kidneys), which can lead to secondary hypertension. ### Diagnosis Diagnosing Takayasu’s arteritis can be challenging, especially in the early stages when symptoms are nonspecific. Diagnosis usually involves a combination of clinical findings, imaging studies, and laboratory tests. 1. **Physical Examination**: - **Pulse Examination**: Weak or absent pulses in one or more extremities. - **Blood Pressure Measurements**: A significant discrepancy between the two arms or between the arms and legs. - **Bruits**: Audible sounds heard over affected arteries due to turbulent blood flow. 2. **Laboratory Tests**: - **Inflammatory Markers**: - **Elevated ESR (Erythrocyte Sedimentation Rate)** and **CRP (C-Reactive Protein)** are common, indicating inflammation. - These markers help in monitoring disease activity but are not specific to Takayasu’s arteritis. - **Anemia**: Mild anemia may be present due to chronic inflammation. 3. **Imaging Studies**: - Imaging is essential for confirming the diagnosis and assessing the extent of arterial involvement. - **Magnetic Resonance Angiography (MRA)** and **Computed Tomography Angiography (CTA)**: - These are the preferred imaging modalities, providing detailed images of the aorta and its branches, showing areas of narrowing, thickening, or aneurysm. - **Ultrasound**: - Doppler ultrasound can be used to evaluate blood flow in affected arteries, especially in the carotid and subclavian arteries. - **Conventional Angiography**: - Provides high-resolution images of the blood vessels and is used when planning surgical or interventional treatment. 4. **Biopsy**: - Biopsy is rarely done for Takayasu’s arteritis because of the inaccessibility of large blood vessels. Diagnosis is typically made based on clinical and imaging findings. ### Treatment The goal of treatment is to reduce inflammation, prevent progression of vascular damage, and manage symptoms. 1. **Medications**: - **Corticosteroids**: - Prednisone is the mainstay of treatment, effectively reducing inflammation in most cases. - Treatment typically begins with a high dose, which is tapered gradually over time to avoid long-term side effects. - **Immunosuppressive Agents**: - Used as steroid-sparing agents or in patients who do not respond to corticosteroids alone. - Options include **methotrexate**, **azathioprine**, and **mycophenolate mofetil**. - **Biologic Agents**: - For patients with refractory or relapsing disease, biologic agents targeting specific inflammatory pathways, such as **TNF inhibitors** (e.g., infliximab) or **IL-6 inhibitors** (e.g., tocilizumab), may be effective. - **Antihypertensives**: - Blood pressure control is essential, especially in cases with renal artery involvement. Commonly used drugs include ACE inhibitors, ARBs, or calcium channel blockers. 2. **Surgical and Interventional Treatment**: - Surgery or interventional procedures may be required for patients with severe stenosis, occlusion, or aneurysms. - **Angioplasty with or without Stenting**: - Percutaneous angioplasty may be used to open narrowed arteries. Stenting can help keep the artery open. - **Bypass Surgery**: - In cases of critical vessel occlusion, surgical bypass may be performed to restore blood flow around the affected segment. - **Aneurysm Repair**: - Large aneurysms may require surgical repair to prevent rupture. 3. **Monitoring and Follow-up**: - Regular monitoring with imaging and laboratory tests is necessary to assess disease activity and detect progression or complications. - Adjustments in immunosuppressive therapy are made based on disease activity and response to treatment. ### Prognosis and Complications With early diagnosis and effective treatment, many patients with Takayasu’s arteritis can achieve remission and have a good quality of life. However, complications can occur, especially if the disease is not well-controlled: 1. **Complications**: - **Aneurysms**: Increased risk of aneurysm formation, which can lead to rupture. - **Stroke or Transient Ischemic Attacks (TIA)**: Due to involvement of the carotid or vertebral arteries. - **Hypertension**: Secondary to renal artery stenosis or involvement of other major arteries. - **Heart Failure**: Due to prolonged hypertension and left ventricular hypertrophy. 2. **Prognosis**: - The course of Takayasu's arteritis is variable. Some patients achieve long-term remission, while others may have a relapsing-remitting course. - Early and aggressive treatment is essential for preventing vascular complications. ### Summary - **Takayasu’s Arteritis** is a chronic inflammatory disease of large vessels, primarily affecting the aorta and its branches. - **Symptoms** include nonspecific systemic symptoms early on, followed by signs of vascular insufficiency, such as weak pulses, blood pressure discrepancies, and claudication. - **Diagnosis** is based on clinical examination, inflammatory markers, and imaging studies (MRA, CTA, Doppler ultrasound). - **Treatment** involves corticosteroids, immunosuppressive agents, and biologic drugs, with surgery or angioplasty for severe vascular involvement. - **Prognosis** varies, but complications like hypertension, aneurysms, and stroke can occur if not well managed. Takayasu's arteritis requires lifelong follow-up and careful management to control inflammation and prevent vascular complications. ### Reference: - ### Connected Documents: -