Cardiac diseases in AIDS overview

# Overview
HIV/AIDS is the fourth leading cause of death worldwide due to its increasing incidence. Introduction of HAART for the treatment of patients infected with HIV has improved their survival. As a result, as mortality has decreased, a higher number of patients is found to have heart diseases. In fact, a recent study found that about 24% of patients infected with HIV suffer from a cardiac condition.

# Pathophysiology
Many observational studies have shown that HIV-infected patients are at an increased risk for developing a variety of cardiac diseases.  With the introduction of HAART, longevity of HIV-infected patients increased, in turn leading to increased prevalence of cardiac and allied diseases. Inflammation and immune regulation leading to atherogenesis, endothelial dysfunction and coagulation abnormalities have been suggested as the major factors in the pathogenesis of cardiovascular diseases in AIDS. Compared to age-matched uninfected controls, HIV-infected patients have a higher risk of myocardial infarction and cardiovascular death, even with effective anti-retroviral therapy.  Concerns have been raised that HAART by itself is associated with increased risk of peripheral artery disease and coronary artery disease.

# Epidemiology and Demographics
Incidence of many cardiovascular diseases has increased after the use of anti-retroviral therapy in the treatment of HIV infection.

# Diagnosis

## History and Symptoms
Pericardial effusion is the most common manifestation of cardiovascular disease in patients with AIDS. However, the majority of the cases of pericardial effusion are asymptomatic and are detected incidentally on chest x-rays which may show increased cardiac silhouette. Other symptoms vary with the type of cardiac disease in AIDS.

## Physical Examination
Pericarditis in AIDS presents as small, asymptomatic pericardial effusions. However, when severe, it may present as fever, chills and weakness. The classic sign of pericarditis is apericardial friction rub. Other cardiac presentations in AIDS include heart failure, endocarditis and coronary artery disease.

## Laboratory Findings
Laboratory findings depend on the type of disease affecting the heart. Blood cultures and serology are used to diagnose infections causing pericarditis and myocarditis. Increased serum troponins may be elevated in myocardial injury.

## Electrocardiogram
In an analysis of 4518 HIV-infected patients, it was found that more than half of the participants (51.5%) had either minor or major ECG abnormalities. Minor ECG abnormalities (48.6%) were more common than major ECG abnormalities (7.7%).

## Imaging

### Chest X-Ray
Chest X ray abnormalities in HIV infected patients are seen in the presence of congestive cardiac failure and pericardial effusions. These include cardiomegaly and pulmonary congestion.

### Echocardiography
Echocardiography is the most specific test for diagnosing the degree of systolic LV dysfunction in HIV infected patients with cardiomyopathy. Common findings include effusions and ventricular dysfunction.

## Other Diagnostic Studies
Echocardiography guided endomyocardial biopsy may be required to diagnose the potentially treatable causes of cardiac diseases such as myocarditis and cardiomyopathy.

# Treatment

## Medical Therapy
If the patient is not on antiretroviral therapy, medical therapy for cardiac diseases in HIV infected patients requires multidisciplinary care involving the cardiology and the infectious disease departments. The aim of the medical therapy is to formulate an individualized treatment plan based on risk factors. Drug therapy for cardiac diseases in HIV patients is the same as that for cardiac diseases in the general population, except for consideration for interactions of these drugs with HAART. Nervertheless, the benefits of HAART outweigh the risks of drug-drug interactions between HAART and cardiac drugs. In addition, cardiotoxic drugs need to be discontinued.

## Surgery
Unless the patient has advanced immunosuppression or is at high risk for mortality from HIV related complications, cardiovascular surgical procedures like valve replacement and coronary artery bypass can be performed safely.

## Prevention
Statins and aspirin have shown to reduce mortality from CVD in general population, but their use in HIV infected population is uncertain.