Cardiac Disease

A wide variety of cardiac abnormalities have been reported in HIV-infected patients, including ventricular dysfunction myocarditis, pericarditis, endocarditis, and arrhythmias. Most often, cardiac involvement is clinically silent and is noted as an incidental finding at autopsy. When clinical symptoms are present, however, disease manifestations can be debilitating, and, in many cases, life threatening. Unlike HIV-associated renal disease, no specific cardiac syndrome or disease state has been described.

Epidemiology
Cardiac abnormalities have been observed in 25 to 75% of HIV-infected patients studied at autopsy. Myocardial disease is noted most frequently, occurring in >90% of subjects with cardiac findings. Pericardial disease, often with adjacent myocardial involvement, is observed in >20% of cases with cardiac abnormalities. Endocarditis is evident histologically in 3 to 5% of cases reported in autopsy series. No characteristic epidemiologic factor, such as age, gender, race, or means of acquiring HIV infection, has been identified which predisposes patients to cardiac disease. Although cardiac abnormalities are observed more frequently in AIDS patients, up to 30% of patients with early symptomatic HIV disease are noted to have abnormal findings on echocardiograms and electrocardiograms.

Pathology and Pathogenesis
HIV-related heart disease may result from metastatic extension of a concomitant opportunistic infection or malignancy but most often is seen as lymphocytic infiltration of the myocardium or as an unspecified myocarditis. The mechanism responsible for the myocarditis remains unknown, although many investigators believe that HIV itself may be directly responsible. Other viruses, such as CMV, may be responsible for the development of myocarditis, although the typical “owl’s eye” inclusion bodies are rarely seen in patients with HIV-associated cardiomyopathy. Additional mechanisms, such as postviral myocarditis or catecholamine-induced myocarditis, have been postulated, but little evidence exists to support their role.

A broad range of opportunistic infections and malignant diseases has been described in cardiac tissue examined at autopsy. Among the infectious disorders, fungal and viral pathogens are identified most often, followed by bacterial and protozoal infections (

Table 417-2). Although the invading pathogen is frequently diagnosed at another primary site antemortem, cardiac involvement is rarely (<2%) identified before autopsy. This is largely due to the clinically silent nature of cardiac disease in HIV infection and a low index of suspicion by clinicians. Kaposi’s sarcoma and metastatic lymphoma are the most common neoplastic diseases reported that invade the heart. Primary cardiac lymphoma has been reported rarely.

Pericardial disease is almost invariably associated with adjacent myocardial involvement. Pericarditis is usually nonspecific in origin, but when an etiologic process is identified, Kaposi’s sarcoma or a pathogen, such as Mycobacterium tuberculosis or Cryptococcus neoformans, is responsible most often. Drugs used to treat HIV-associated disorders, such as doxorubicin for Kaposi’s sarcoma, may cause myocardial damage. Other toxins, vitamin deficiencies, or metabolic abnormalities (e.g., hypothyroidism) may also result in myocardial dysfunction or pericardial disease.

Endocardial disease has been described in up to 3% of cases studied at autopsy and usually presents as either nonbacterial thrombotic (marantic) endocarditis or healed bacterial endocarditis. The precise etiology of marantic endocarditis is unknown, but it has been reported in other long-term wasting illnesses and malignant diseases. Vegetations are usually located on the mitral valve, although lesions on the tricuspid valve have been noted in up to 29% of AIDS patients with this disorder. Significant embolization to the spleen and brain was noted in >50% of patients with marantic endocarditis studied at autopsy. Bacterial endocarditis is reported rarely in AIDS patients. Healed lesions from previous bouts of bacterial endocarditis have been reported in autopsy series but are of little clinical significance.

Clinical Findings
Most cardiac disease in HIV-infected patients is clinically silent. When symptoms are present they usually consist of the ordinary findings noted in non-HIV-infected patients with myocarditis or pericarditis, such as fever, dyspnea, chest pain, fatigue, cough, and orthopnea. Hepatomegaly and jugular venous distention are the most common signs noted on physical examination, followed by rales, systolic murmurs, and the presence of an S3 gallop. Signs of advanced pericardial disease with impending tamponade are among the most common clinical manifestations observed in patients who present with clinical symptoms of cardiac disease.

Diagnosis
Demonstrated cardiomegaly on a chest roentgenogram is an important marker of underlying cardiac disease in HIV-infected patients. Right ventricular enlargement is usually the result of pulmonary artery hypertension, which in AIDS patients is often due to severe or recurrent opportunistic pneumonia. Left ventricular or biventricular enlargement is a characteristic finding of congestive cardiomyopathy due to any cause. Echocardiography is a more sensitive and specific noninvasive test that is used to assess the degree of ventricular dysfunction and to characterize the extent of pericardial effusion, if present.

Several series have demonstrated echocardiographic abnormalities in up to 50% of HIV-infected patients who had no cardiac symptoms at the time of study. Ventricular enlargement, pericardial effusion, and ventricular hypokinesis were the abnormalities noted most frequently. In view of the overall silent nature of cardiac disease, the high likelihood that infiltrative processes will be evident and diagnosed at another site, and the often limited therapeutic options available for treating cardiac disease in HIV-infected patients, routine echocardiography should be discouraged in those without cardiac symptoms. The experience with endomyocardial biopsies in HIV-infected patients is quite limited; however, in those individuals who show signs of cardiac disease and have not had a specific diagnosis established, endomyocardial biopsy is a viable option for a definitive diagnosis.

Treatment
Supportive treatment consisting of diuretic therapy, reducing preload and afterload when appropriate, and correcting cardiac arrhythmias is the obvious initial approach to treating myocardial disease. Pericardial disease requires careful volume management with avoidance of aggressive diuresis or preload reduction. In the case of pericardial tamponade, surgical intervention is warranted. When the underlying etiology of the cardiac disease is known, appropriate therapy directed at the specific infectious agent or malignancy is indicated.

Provided by ArmMed Media
Revision date: June 11, 2011
Last revised: by Sebastian Scheller, MD, ScD