Pulmonary Hypertension: ICD-10 I27.0, I27.2

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1 Dr Manish Barman, MD. Membership and Affiliations ESC, European association of cardiovascular prevention and rehabilitation. Acute Cardiovascular Care Association. ESC, Working Group on Hypertension & the Heart. ESC, Working Group on e-cardiology. American College of Cardiology. American Heart Association. Corresponding address: Department of cardiology. Al Ahli Hospital, Doha, Qatar. Pulmonary Hypertension: ICD-10 I27.0, I27.2

2 Pulmonary Hypertension: ICD-10 I27.0, I27.2 What is pulmonary hypertension? Pulmonary hypertension is a rare lung disorder in which the arteries that carry blood from the heart to the lungs become narrowed, making it difficult for blood to flow through the vessels. As a result, the blood pressure in these arteries -- called pulmonary arteries -- rises far above normal levels. This abnormally high pressure strains the right ventricle of the heart, causing it to expand in size. Overworked and enlarged, the right ventricle gradually becomes weaker and loses its ability to pump enough blood to the lungs. This could lead to the development of right heart failure. Pulmonary arterial hypertension (PAH), defined as a mean pulmonary arterial pressure greater than 25 mm Hg at rest or greater than 30 mm Hg during exercise, is characterized by a progressive and sustained increase in pulmonary vascular resistance that eventually leads to right ventricular (RV) failure. It is a life-threatening condition if untreated; treatment success rates vary according to the specific cause. Pulmonary hypertension occurs in individuals of all ages, races, and ethnic backgrounds although it is much more common in young adults and is approximately twice as common in women as in men. What are the symptoms of pulmonary hypertension? Symptoms do not usually occur until the condition has progressed. The first symptom of pulmonary hypertension is usually shortness of breath with everyday activities, such as climbing stairs. Fatigue, dizziness, and fainting spells also can be symptoms. Swelling in the ankles, abdomen or legs; bluish lips and skin, and chest pain may occur as strain on the heart increases. Symptoms range in severity and a given patient may not have all of the symptoms. The shortness of breath usually starts slowly and gets worse over time. Often, a person notices he or she can't perform the same activity as before without becoming breathless. In more advanced stages of the disease, even minimal activity will produce some of the symptoms. Additional symptoms include irregular heart beat (palpitations or strong, throbbing sensation), racing pulse, passing out or dizziness, progressive shortness of breath during exercise or activity, and difficulty breathing at rest. Eventually, it may become difficult to carry out any activities as the disease worsens.

3 Figure 1. Illustrating common symptoms of pulmonary hypertension. Why do the pulmonary arteries narrow? Scientists believe that the process starts with injury to the layer of cells that line the small blood vessels of the lungs. This injury, which occurs for unknown reasons, may cause changes in the way these cells interact with the smooth muscle cells in the vessel wall. As a result, the smooth muscle contracts more than normal and narrows the vessel. Causes of Pulmonary Hypertension Many different conditions can cause pulmonary hypertension. In different ways, each of these illnesses may lead to high blood pressure in the pulmonary arteries: Congestive heart failure Venous thromboembolic disease (blood clots in the lungs) Human immunodeficiency virus infection Illegal drug use (cocaine, methamphetamine) Cirrhosis of the liver Appetite suppressant medications (fenfluramine, dexfenfluramine, diethylpropion).

4 Autoimmune diseases (lupus, scleroderma, and rheumatoid arthritis) Heart shunts (abnormal blood flow between heart chambers) Chronic lung disease (emphysema, chronic bronchitis, or pulmonary fibrosis) Obstructive sleep apnea When no cause can be identified after testing, the condition is called idiopathic pulmonary arterial hypertension. This condition was formerly known as primary pulmonary hypertension. Etiology Pulmonary hypertension was previously divided into 2 categories, primary and secondary, depending on whether a specific cause could be identified. In 1998, the World Health Organization (WHO) proposed a clinical classification of pulmonary hypertension into 5 main groups on the basis of similarities in pathophysiology, clinical presentation, and therapeutic options. This classification was later revised in Venice in 2003 and again in Dana Point in 2008 to further clarify classifications. Group 1, PAH, is further divided into the following 4 subgroups: Subgroup 1 - Idiopathic PAH (IPAH) Subgroup 2 - Heritable PAH, including those with BMPR2 and ALK2 gene mutations Subgroup 3 - Drug- and toxin-induced PAH (Aminorex, fenfluramine derivatives, and toxic rapeseed oil have been identified as definite risk factors for PAH. Subgroup 4 - Conditions with known localization of lesions in the small pulmonary arterioles, including collagen-vascular disease (scleroderma/crest syndrome), congenital left-to-right shunts, Porto pulmonary hypertension, HIV-associated pulmonary hypertension, schistosomiasis, and chronic hemolytic anemia. Subgroup 5 Persistent pulmonary hypertension of the newborn. Group 2, pulmonary hypertension owing to left-sided heart disease, consists of left-sided myocardial and valvular diseases and extrinsic compression of the pulmonary veins (eg, tumors) and pulmonary veno-occlusive disease. Group 3, pulmonary hypertension owing to lung diseases and/or hypoxia, consists of diseases that cause inadequate arterial oxygenation. Such conditions include lung disease (eg, chronic obstructive pulmonary disease [COPD] and interstitial lung disease), impaired respiration (eg, obstructive sleep apnea [OSA] and alveolar hypoventilation disorders), and long-term exposure to high altitude. Group 4, is chronic thromboembolic pulmonary hypertension (CTEPH). Group 5, pulmonary hypertension with unclear or multifactorial etiologies, is further divided into the following 4 subgroups: Subgroup 1 - Hematologic disorders, including myeloproliferative disorders

5 Subgroup 2 - Systemic disorders, including sarcoidosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, neurofibromatosis, and vasculitis. Subgroup 3 - Metabolic disorders, including glycogen storage disease, Gaucher disease, and thyroid disorders Subgroup 4 - Miscellaneous conditions, including tumor obstruction, Mediastinal fibrosis, and chronic renal failure on dialysis. On the basis of information adapted from the executive summary of the world symposium on Primary Pulmonary Hypertension in Evian, France, in 1998, pulmonary hypertension may be divided into the following functional classes: Class I These are patients with pulmonary hypertension but without resulting limitation of physical activity; ordinary physical activity does not cause undue dyspnea or fatigue, chest pain, or near-syncope. Class II These are patients with pulmonary hypertension resulting in slight limitation of physical activity; they are comfortable at rest, but ordinary physical activity causes undue dyspnea or fatigue, chest pain, or near-syncope Class III These are patients with pulmonary hypertension resulting in marked limitation of physical activity; they are comfortable at rest, but even less-than-ordinary activity causes undue dyspnea or fatigue, chest pain, or near-syncope Class IV These are patients with pulmonary hypertension who are unable to perform any physical activity without symptoms; these patients manifest signs of right-sided heart failure; dyspnea or fatigue may even be present at rest, and discomfort is increased by any physical activity. CTEPH occurs in a minority of patients after acute embolism. Approximately 0.1% of survivors develop progressive pulmonary hypertension. Less than 1% of these patients have deficiencies of antithrombin 3, protein C, or protein S. No consistent defect in fibrinolytic activity has been identified. Pathologically, these patients have a full range of pulmonary hypertensive lesions, including plexogenic lesions in the small pulmonary arteries. These patients present with progressive dyspnea and exercise intolerance. Physical examination findings demonstrate RV failure and PAH. Genetic predisposition. Pulmonary hypertension is inherited in a small number of cases. Knowing that someone in the family had or has pulmonary hypertension should prompt you to seek early evaluation should symptoms occur. Pulmonary hypertension may also be caused by other conditions, and in some cases, the cause is unknown. ACVRL1: Somatic mosaicism in ACVRL1 are associated with severe pulmonary arterial hypertension in siblings.

6 How is pulmonary hypertension diagnosed? Because pulmonary hypertension may be caused by many medical conditions, a complete medical history, physical exam, and description of your symptoms are necessary to rule out other diseases and make the correct diagnosis. During the physical exam, your health care provider will: Listen for abnormal heart sounds such as a loud pulmonic valve sound, a systolic murmur of tricuspid regurgitation, or a gallop due to ventricular failure. Examine the jugular vein in the neck for engorgement. Examine the abdomen, legs, and ankles for fluid retention. Examine nail beds for bluish tint. Look for signs of other underlying diseases that might be causing pulmonary hypertension. Other tests that might be ordered include: Blood tests: o Complete metabolic panel (CMP): Examines liver and kidney function o Autoantibody blood tests, such as ANA, ESR, and others: Screens for collagen vascular diseases o Thyroid stimulating hormone (TSH): A screen for thyroid problems o HIV: A screen for human immunodeficiency virus o Arterial blood gases (ABG): Determines the level of oxygen in arterial blood. o Complete blood count (CBC): Tests for infection, elevated hemoglobin, and anemia o B-type natriuretic peptide (BNP): A marker for heart failure 6 minute walk test: Determines exercise tolerance level and blood oxygen saturation level during exercise. Pulmonary function tests: Evaluates for other lung conditions such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis among others. Polysomnogram or overnight oximetry: Screens for sleep apnea (results in low oxygen levels at night). Chest X-ray: Shows an enlarged right ventricle and enlarged pulmonary arteries. Figure 2. Chest radiograph of patient with secondary pulmonary arterial hypertension shows enlarged pulmonary arteries. This patient had atrial septal defect.

7 Doppler echocardiogram: Uses sound waves to show the function of the right ventricle, to measure blood flow through the heart valves, and then calculate the systolic pulmonary artery pressure. Figure 3. Apical 4 chamber view showing dilated right atrium and ventricles. Figure 4. Doppler estimation of pulmonary artery pressure. Chest CT scan: Looks for blood clots and other lung conditions that may be contributing to or worsening pulmonary hypertension.

8 Right heart catheterization: Figure 5. Right heart catheterization Measures various heart pressures (ie, inside the pulmonary arteries, coming from the left side of the heart), the rate at which the heart is able to pump blood, and finds any leaks between the right and left sides of the heart. Ventilation perfusion scan (V/Q scan): Looks for evidence of blood clots along the pathway to the lungs. Pulmonary angiogram: Looks for blood clot blockages in the pulmonary arteries. Differential Diagnoses Apnea, Sleep Arteriovenous Malformations Atrial Myxoma Atrial Septal Defect Cardiomyopathy, Dilated, Hypertrophic, Restrictive Chronic Obstructive Pulmonary Disease, Emphysema Mitral Regurgitation, Mitral Stenosis Pulmonary Hypertension, Primary Restrictive Lung Disease Systemic Lupus Erythematosus

9 How is pulmonary hypertension treated? Appropriate diagnosis and analysis of the problem is necessary before starting any treatment. Treatment varies per individual based on the different underlying causes but generally includes taking medications; making lifestyle and dietary changes; having surgery, if necessary; and seeing your doctor regularly. Listed below are medication and surgical treatment approaches. Medications Many different types of medications are available to treat pulmonary hypertension. Treatment choices, such as those listed below, depend on the severity of pulmonary hypertension, the likelihood of progression, and individual drug tolerance. Oxygen replaces the low oxygen in your blood. Anticoagulants or "blood thinners" such as warfarin sodium, decreases blood clot formation so blood flows more freely through blood vessels. Diuretics or "water pills" [such as furosemide, spironolactone] removes extra fluid from the tissues and bloodstream, which reduces swelling and makes breathing easier. Potassium (such as K-dur ) replaces potassium (an essential nutrient) that may be lost with increased urination when taking diuretics. Inotropic agents (such as digoxin) improves the heart s pumping ability. Vasodilators [such as nifedipine or diltiazem] lowers pulmonary blood pressure and may improve the pumping ability of the right side of the heart. Endothelin-receptor antagonists Bosentan, ambrisentan helps block the action of Endothelin, a substance that causes narrowing of lung blood vessels. These medications require monthly lab work to monitor liver function. Prostacyclins: Epoprostenol, treprostinil sodium, iloprost dilates pulmonary arteries and helps prevent blood clots from forming. Soluble guanylate cyclase (sgc) stimulators, soluble guanylate cyclase (sgc) is an enzyme in the cardiopulmonary system and the receptor for nitric oxide (NO). Pulmonary arterial hypertension (PAH) is associated with endothelial dysfunction, impaired synthesis of NO, and insufficient stimulation of the NO-sGC-cGMP pathway. Riociguat is the first sgc stimulator approved in the United States. Approval was based on data from the 2 randomized, double-blind, placebocontrolled, global phase III studies CHEST-1 and PATENT-1, as well as long-term data from these studies. In each study, Riociguat significantly improved exercise capacity and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension. Riociguat elicits a dual mode of action. It sensitizes sgc to endogenous NO by stabilizing the NOsGC binding, and it directly stimulates sgc via a different binding site, independently of NO. It is indicated for chronic thromboembolic pulmonary hypertension and PAH. Sildenafil, tadalafil relaxes pulmonary smooth muscle cells, which leads to dilation of the pulmonary arteries.

10 Surgical therapies Pulmonary thromboendarterectomy: If present, a large clot in the pulmonary artery may be surgically removed to improve blood flow and lung function. Lung transplantation: Currently, this is the only cure for primary pulmonary hypertension. Transplantation is reserved for advanced pulmonary hypertension that is not responsive to medical therapy. The right side of the heart will generally return to normal after the lung/lungs have been transplanted. Your health care provider will discuss transplantation if it is an appropriate treatment option for your condition. Heart/lung transplantation: This type of double organ transplant is very rare but is necessary for all patients who have combined lung and left heart failure. Prognosis Increasing pulmonary arterial pressure is associated with a progressive decline in survival for patients with COPD or other interstitial lung diseases. The prognosis of patients with SPAH is variable and depends on the severity of hemodynamic derangement and the underlying primary disorder. Patients with severe pulmonary hypertension or right-sided heart failure survive approximately 1 year. Patients with moderate elevations in pulmonary arterial pressure (mean pressure below 55 mm Hg) and preserved right-sided heart function have a median survival of 3 years from diagnosis. Dr Manish Barman, MD. drbarman@yahoo.com