High prevalence of asymptomatic cardiac abnormalities in patients with HIV

Asymptomatic cardiac abnormalities are common among HIV-positive patients, US investigators report in the online edition of Clinical Infectious Diseases.  

Much higher than expected rates of structural and functional cardiac abnormalities were detected when a large number of patients were monitored using echocardiograms.

“Cardiac abnormalities were commonly detected by echocardiography, despite the relatively young age and high CD4 cell counts of participants,” comment the investigators.

However, many of the risk factors associated with the cardiac abnormalities were potentially modifiable.

Thanks to the effectiveness of antiretroviral therapy many patients with HIV can expect to live well into older age.

But there is concern that some individuals have an increased risk of cardiovascular disease. Research suggests that patients with HIV are more likely to have a heart attack or stroke than their HIV-negative peers. The causes of this increased cardiovascular risk seem to include HIV itself, therapy with some antiretroviral drugs and traditional factors such age, smoking and diet.

Prevention of cardiovascular disease is an increasingly important component of HIV care. As many of the risks are potentially modifiable, early detection of problems means that patients can be encouraged and supported to make lifestyle changes that reduce their risk of experiencing a cardiac event.

However, little is known about the prevalence and risk factors of asymptomatic structural and functional cardiac dysfunction. Therefore investigators from the US Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN Study) monitored 656 patients for these abnormalities using echocardiography.

The research was conducted between 2004 and 2006. The patients had a median age of 41 years. Most (76%) were men, 71% were white, and 73% were taking anti-HIV drugs. The patients had well-preserved immune function and their median CD4 cell count was 462 cells/mm³. Nearly all (91%) of the individuals who were receiving antiretroviral therapy had a viral load below 400 copies/ml.

Only a third of patients were found to have normal cardiac function and structure.

Results showed that 18% of individuals had left ventricular systolic dysfunction; 26% had diastolic dysfunction; 57% pulmonary hypertension; left ventricular hypertrophy was present in 7% of individuals, and left atrial enlargement in 40%.

The investigators note that these prevalences are much higher than those seen in the general US population. For example, in one recent study only 5% of HIV-negative patients had an enlarged left atrium.

Statistical analysis showed that a range of risk factors were associated with the abnormalities observed in the HIV-positive patients.

Those for left ventricular systolic dysfunction included a history of heart attack (p = 0.019), high levels of a marker of inflammation, C-reactive protein (p = 0.033), and smoking (p = 0.036).

Diastolic dysfunction was also associated with high levels of C-reactive protein (p = 0.027) and high blood pressure (p = 0.003).

Risk factors for pulmonary hypertension included current use of the protease inhibitor ritonavir (p = 0.037).

The investigators identified high blood pressure (p = 0.002), diabetes (p = 0.003), black race (p = 0.006), elevated C-reactive protein (p = 0.15) and current treatment with abacavir (p = 0.02) as risk factors for left ventricular hypertrophy. Women with a body mass index above 25 also had an increased risk of this abnormality.

Only two factors were associated with left atrial enlargement: high blood pressure (p = 0.008) and recent use of cannabis (p = 0.013).

None of these risk factors were “unexpected” comment the investigators, and they stress that many are potentially modifiable.

They therefore conclude, “our results support lifestyle modifications, such as cessation of smoking and weight loss, as continued priorities in the chronic management of HIV infection.”