Autoimmune diseases of connective tissue and cardiovascular involvement

August 2, 2011

Connective tissue disorders are a cluster of autoimmune diseases in which antibodies are generated against certain cell proteins (part of connective tissue), which trigger a potent inflammatory response that particularly involves the arterial wall. Thus, cardiovascular involvement is very common in these patients. Because the autoimmune processes are stimulated by the high levels of estrogen in the childbearing years, diseases such as Rheumatoid arthritis, Systemic lupus erythematosus, sarcoidosis, systemic vasculitis (Takayasu and giant cell arteritis) much more often affect women than men.

The prototype of these autoimmune diseases is Systemic lupus erythematosus. The cardiovascular involvement of Systemic lupus erythematosus is ubiquitous and CVD is the most common cause of death in patients with longstanding lupus. Pericarditis, the inflammatory involvement of the pericardium (membrane surrounding the heart), is the most common cardiac problem in lupus (30% of patients have clinically significant disease), and can develop at anytime during the course of Systemic lupus erythematosus. Although the clinical course of pericarditis is usually benign, it can acutely lead to hemorrhagic cardiac tamponade (compression of the heart by blood in the pericardium) requiring immediate removal or long-term consequences such as constrictive pericarditis (due to chronic thickening and calcification of the pericardium). Other than valvular involvement (discussed above), Systemic lupus erythematosus can affect both the coronary arteries and the cardiac muscle itself. Middle-aged women with active lupus are more than 50 times more likely to develop myocardial infarction and this has been associated with disease duration, period of time treated with corticosteroids, postmenopausal status, and hypercholesterolemia. There is a high prevalence of subclinical Coronary artery disease in women with Systemic lupus erythematosus. It is due to accelerated atherosclerosis, inflammatory occlusion of the coronary arteries, and acute thrombosis, especially with high levels of autophospholipid autobodies. The cause of myocardial involvement of Systemic lupus erythematosus is multifactorial but usually manifests as myocarditis (inflammation of the heart muscle by Systemic lupus erythematosus). If Systemic lupus erythematosus causes heart failure in the absence of Coronary artery disease or valve disease, this may warrant a trial of corticosteroid therapy.

Antiphospholipid antibody syndrome (APLAS) can occur in the presence or absence of Systemic lupus erythematosus. In the absence of other autoimmune diseases, APLAS does not cause myocarditis, pericarditis (inflammation of tissue around the heart), or conduction disease. APLAS may induce coronary artery thrombosis (blockage of the coronary arteries) with subsequent myocardial infarction and nonbacterial endocarditis.

Rheumatoid arthritis and systemic scleroderma also produce an acute inflammatory pericarditis but more often are associated with chronic, small pericardial effusions (fluid around the heart) or calcification of the pericardium. Although Rheumatoid arthritis has not been associated with myocarditis, rheumatoid nodules (tissue nodules which occur in Rheumatoid arthritis) can localize to and destroy the cardiac conduction system causing heart block. Systemic scleroderma can involve the conduction system (system transmitting cardiac activity through the heart) but more often causes patchy microinfarcts (mini-infarcts). Individuals who have a history of palpitations (very rapid heartbeat) or syncope (fainting spells) have a high risk of sudden death, warranting the prophylactic (preventative) implantation of cardioverter devices (devices that correct abnormal heart rhythm).

Takayasu arteritis is an inflammatory disease involving the aorta and its major branches. It is most often present in young women (women are affected 10 times more than men). The long-term consequences of this disease are hypertension, aortic aneurysm, and renal insufficiency due to renal artery stenosis (narrowing), and more rarely myocardial infarction due to coronary artery involvement. Giant cell arteritis is another inflammatory disease of the medium arteries, which affects older patients (usually over 70 years) and especially women (2-3:1 vs. men). The most common involvement is the temporal artery, near the eye, which manifests as severe headache or transient cerebral ischemic attacks (transient failure of blood flow to the brain). It responds very well to corticosteroids.

SEE ALSO: Acute myocardial infarction, Cholesterol, Coronary risk factors, Diabetes, Hormone replacement therapy, Hypertension, Oral contraception, Smoking, Stroke, Systemic lupus erythematosus, Venous thromboembolism


Category: Cardiovascular Disease