Researchers from Spain have shown that HIV causes structural heart disease. These findings support the introduction of cardiovascular screening for all HIV patients, particularly those who have a positive viral load.
Presenting their findings at the EuroEcho-Imaging 2013 annual meeting, held in Istanbul, Turkey, Dr. Nieves Montoro, from Madrid, said:
"It is well known that patients with HIV have a high incidence of structural heart disease (mainly diastolic dysfunction and pulmonary hypertension) as measured by echocardiography but the reason is not clear. We decided to conduct a study to evaluate whether the stage of HIV or the detectable blood viral load were related to the degree of heart disease."
The Centers for Disease Control and Prevention (CDC) estimates that there are 1,144,500 people aged over 13 living with HIV in the US.
For the study, researchers analyzed data from 65 HIV patients, with an average age of 48. All the participants reported shortness of breath - dyspnea - which was graded as greater than class II on the New York Heart Association (NYHA) scale.
According to the Heart Failure Society of America, the NYHA scale is used by physicians to determine the stage of heart failure in patients and focuses on the patient's symptoms in relation to their daily activities and quality of life.
It ranges from class I with mild symptoms through to IV, where symptoms are severe and patients are unable to perform any physical activity without discomfort. This study focuses on classes III and IV, where patients display moderate to severe symptoms.
Counting T-cells and viral loads
Researchers found that HIV patients with a high viral load were at an increased risk of structural heart disease.
AIDs.gov explains that while there is no "normal" viral load, as people who are not infected have no viral load, it is considered "undetectable" if the test measures are less than 40-75 copies in 1 milliliter of blood.
Patients were also given a transthoracic echocardiogram to see if they had structural heart disease (ventricular hypertrophy, systolic or diastolic dysfunction or pulmonary hypertension). Cardiovascular risk factors, such as diabetes, hypertension, smoking status and renal failure, were also assessed.
The researchers found that almost half of the patients (47%) had some type of structural heart disease, usually left ventricular hypertrophy, left ventricular dysfunction, pulmonary hypertension and signs of right ventricle failure.
HIV patients with dyspnea 'should undergo ECG'
Interestingly, the research showed that patients with a positive viral load displayed a significantly higher incidence of structural heart disease than those with an undetectable load - 75% as opposed to 43%.
Dr. Montoro explains:
"We found that half of HIV patients with dyspnea had echocardiographic evidence of structural heart disease. Our most interesting finding was that patients with a positive blood viral load had a significantly higher incidence of structural heart disease. In fact, having a detectable blood viral load nearly doubled the prevalence of heart disease, suggesting that HIV itself might be an independent causal agent."
Dr. Montoro continues:
"Because of the high incidence of cardiac problems in our study (almost 50%), we think that all HIV patients with dyspnea should undergo a transthoracic echocardiogram to check for structural heart disease. This is a non-invasive, cost-effective and accessible diagnostic test. Furthermore, patients with a positive blood viral load are at nearly twice the risk of structural heart disease and they should receive an echocardiogram whether they are symptomatic or not."
Stressing the importance of cardiovascular screening for all HIV patients, Dr. Montoro concludes:
"Detecting cardiac problems in HIV patients sooner using a simple diagnostic tool like echocardiography will enable us to treat them in the very early stage of the heart damage and improve their prognosis. Patients found to have a detectable blood viral load and/or structural heart disease should have closer follow-up by a cardiologist and their HIV specialist doctor."
Previous research has also highlighted the link between high viral loads and increased heart-attack risks,. One study shows that high-CD4-cell-count (so consequently, low-viral-load) patients have the same risk as the general population, and researchers from Pittsburgh claimed HIV infection is linked with a 50% increased risk of heart attack.