The Heart and Lupus
IntroductionAt some stage in the disease more than half of lupus patients will develop a heart abnormality. It is, therefore, one of the important clinical manifestations of lupus to detect although, of course, it need not necessarily be serious.
Lupus involvement of the heart may affect all its layers: the pericardium, myocardium and endocardium as well as the coronary arteries. Involvement may be primary or secondary to lupus damage to other organs, such as the lungs. In addition, symptoms may be confused with other clinical conditions such as reflux oesophagitis, pleurisy and costochondritis.
Working step-wise through the layers of the heart this chapter will describe how they may be involved in lupus and what the clinical manifestations are.
PericarditisThis is the most common heart abnormality in lupus and reports estimate that 6-45% of lupus patients will have some form of pericardial abnormality (it may, however, go undiagnosed).
Inflammation of the pericardium can cause symptoms due to the inflammatory mediators that accumulate and stimulate pain receptors. In some instances a pericardial effusion will occur and sometimes the effects of pericardial inflammation cause the pericardium to constrict, which may cause additional symptoms. An uncommon complication that may occur is for the pericardium to become infected by organisms (usually bacterial) that are carried to it in the blood.
The following symptoms may occur:
• Sub-sternal pain: this may be aggravated by breathing, coughing, swallowing, twisting or bending forward. There is a range of severity and the symptoms may be intermittent.
• Breathlessness: this is caused because the heart is unable to function efficiently either due to its constriction by the pericardium or by fluid that may collect around the heart muscle.
If a diagnosis is suspected, it can be confirmed by listening to the heart when a friction rub may be heard on auscultation. In addition, characteristic electrocardiographic changes may be present (tall T waves and elevated ST segments). An echocardiogram is useful for visualising pericardial effusions. In the absence of signs and symptoms of a pericardial effusion, fluid drainage is rarely necessary.
MyocarditisThis is not a common problem and estimates suggest that up to only 10% of patients will develop this cardiac abnormality. Acute myocarditis may be associated with a lupus flare, but may be drug induced e.g. due to cyclophosphamide or anti-malarials. Similar inflammation may also be found in skeletal muscles and myocarditis may be part of a generalised myositis. Some reports suggest that anti-RNP antibodies may be more prevalent in these patients. Interestingly, anti-myocardial antibodies have been detected in some patients with lupus but they do not correlate with heart involvement.
Immune complex deposition within the myocardium is also thought to form part of the pathological process by activating the complement cascade.
Clinical symptoms of myocarditis:
Signs of congestive heart failure may also be present, with a gallop rhythm and other heart murmurs that may be heard on auscultation. Conduction abnormalities may occur after myocarditis and are usually transient.
Investigations may demonstrate heart enlargement on x-ray and arrhythmias when the ECG is taken.
EndocarditisIn lupus this can be called Libman-Sachs endocarditis. Inflammation of this heart structure results in small nodules (vegetations) being formed. These range from about 1-4mm in diameter and may be singular or conglomerate and have been described as "mulberry-like clusters". They are usually found near the edge of valves but can also occur between the atrial and ventricular chambers. Some reports suggest that antiphospholipid antibodies are associated with valvular heart disease, particularly affecting the mitral valve.
Clinical symptoms of endocarditis are:
• General malaise
Echocardiography can be used to visualise the vegetations and on auscultation murmurs can be heard as the blood becomes turbulent as it passes the vegetations. Mitral and aortic valves are most commonly involved. Cardiac auscultation should be carried out at each visit to the doctor and echocardiography is indicated if significant or changing murmurs are detected or if cardiac function is changing. Echocardiography is not required if there are no symptoms or physical findings on examination suggestive of valvular heart disease.
Complications of endocarditis may be heart failure which could be due to the valves working inefficiently as a result of them not being able to close properly or due to valve stenosis, where the valves do not open fully. In addition, vegetations may break off from the valves and cause damage in a number of other locations such as the brain where a stroke may occur, the lungs where pulmonary embolism may result and peripheral vessels which may become blocked. Libman-Sachs endocarditis may be complicated by infection as the endocardium will be predisposed to attack by blood borne organisms. There may also be anaemia as a result of the inflammatory process.
Antibiotic prophylaxis may be recommended for selected patients with lupus undergoing procedures associated with a risk of bacteraemia e.g. dental treatment.Valve replacement surgery or valvoplasty may be necessary if severe mitral or aortic valvular insufficiency develops.
For patients with asymptomatic valve thickening, low dose aspirin may be indicated.
Non-bacterial thrombotic endocarditis involved with systemic emboli should be treated with anticoagulation. Invasive cardiac screening is not indicated in asymptomatic patients.
Coronary Artery DiseaseSymptomatic CAD is described in 2-45% of patients with lupus and may lead to acute myocardial infarction. Studies have demonstrated that atherosclerosis may develop earlier in patients with lupus and it has been suggested that there is increased prevalence of traditional risk factors for atherosclerosis. It is thought that autoimmune vascular injury in lupus may predispose to atherosclerosis plaque formation. Rarely is there inflammation of the coronary arteries (vasculitis) which results in occlusion of the vessel.
This means that attention to modifiable risk factors is important e.g. hypertension, hyperlipidaemia, cigarette smoking, obesity, diabetes and sedentary life styles. Some studies have indicated that glucocorticoids may lead to worsening of risk factors e.g. cholesterol, arterial blood pressure and body weight. Whilst hydroxychloroquine has been noted to produce a decrease in plasma cholesterol level. The association with corticosteroid, however, may be associated with disease severity, as patients who receive high doses of glucocorticoids are more likely to have active and severe disease. It is obvious that minimum doses of glucocorticoids, used for the shortest possible time, is recommended. Coronary angiography may help differentiate atherosclerosis from arteritis.
Other abnormalities affecting the heart
ECG ChangesIt is estimated that an abnormal ECG is found in between 34-74% of patients. These abnormal tracings may reflect a primary abnormality of the heart itself, such as pericarditis or myocarditis, or isolated conduction defects may occur such as complete heart block and atrial premature contraction. Sometimes, the abnormal tracings may be secondary to other abnormalities in the body, such as an imbalance in the blood electrolytes e.g. a raised potassium level, which could be associated with kidney disease, or the use of drugs such as corticosteroids and diuretics.
Neonatal Lupus Syndrome (NLS)NLS is a rare complication of lupus pregnancy and congenital complete heart block is one of its features.The presence of maternal IgG anti-Ro (SSA) and anti-La (SSB) antibodies are thought to be associated with damage to the heart's conduction pathways in the fetus. The risk is thought to be between 1-7%.These antibodies should be measured early in pregnancy if they have not already been measured. It has yet to be established if these antibodies are involved in conduction defects that may occur in adult patients.
See chapter - Pregnancy, Contraception and HRT in Lupus
High Blood PressureAbout a quarter of lupus patients will have blood pressure readings over 140/90 at some stage in their clinical course.This may, of course, be unrelated to lupus as it is a common condition but lupus associated causes are kidney disease and corticosteroid treatment.
Treatment of Heart AbnormalitiesSometimes no treatment is required, for example, in small asymptomatic pericardial effusions. If the cause of the heart abnormality is thought to be associated with lupus, treatment should be aimed at reducing inflammation with NSAIDs, anti-malarial agents (e.g. hydroxychloroquine), corticosteroids and sometimes cytotoxic drugs such as azathioprine or cyclophosphamide.
Other drugs may also be necessary to counteract heart arrhythmias (e.g. betablockers) or heart failure (e.g. diuretics). If any part of the heart becomes infected then antibiotics, usually given intravenously, will be necessary. High blood pressure can be treated effectively by such drugs as nifedipine and ACE inhibitors. Drugs such as hydralazine, methyldopa and beta-blockers, which may cause lupus-like syndrome, can also be safely used without exacerbating the disease.
It is recommended that all lupus patients should receive antibiotic prophylaxis prior to and during surgery, including dental procedures.
Table 1 - Chest Pain in Lupus
Chest pain in lupus is a frequent complaint and causes are as follows:
• Heart: Acute lupus pericarditis, coronary artery disease e.g. angina pectoris and other heart abnormalities e.g. mitral valve prolapse
• Lung disease e.g. pleurisy, pneumonia, pulmonary embolism (antiphospholipid syndrome)
• Gastrointestinal disorders e.g. gastritis and peptic ulcer disease
• Musculoskeletal abnormalities: costochondritis or fibromyalgia
• Osteoporosis: corticosteroid therapy may predispose to osteoporosis which could cause rib fractures and vertebral body collapse
• Renal disease: lupus nephritis and nephritic syndromes may be associated with renal vein thrombosis and pleuritic chest pain is a symptom
Prof John Axford
Chair of Clinical Rheumatology
Director of The Sir Joseph Hotung Centre for Musculoskeletal Disorders
University of London and NHS Trust
London SW17 0QT