HIV and the heart
Human immunodeficiency virus infection, if left untreated, progresses to acquired immunodeficiency syndrome, a debilitating condition that severely compromises the immune system. A lesser known fact is that HIV/Aids and its medical treatment are also associated with an increased risk of cardiovascular diseases.
What are the mechanisms of HIV-associated cardiac disease?
HIV can directly infect and damage the endothelial cells representing the inner lining of blood vessels, leading to “endothelial dysfunction”. Endothelial dysfunction contributes to impaired vessel dilation, tendency to clotting or “prothrombotic activity”, and cholesterol plaques build-up or “atherosclerosis”. All these effects promote cardiovascular disease [CVD] development.
HIV infection also triggers general or “systemic” inflammation, characterised by increased levels of inflammatory cytokines and reactive oxygen species. This chronic inflammation accelerates atherosclerosis and contributes to cholesterol plaque instability, leading to plaque rupture and consequent acute cardiovascular events such as a heart attack and a stroke.
HIV exerts a direct effect on the liver and glands, leading to metabolic abnormalities such as hyperlipidaemia and diabetes, which further exacerbate the risk of CVD.
Antiretroviral Therapy or HAART has significantly reduced the incidence of opportunistic infections and other Aids-defining illnesses, allowing HIV-infected individuals to live longer and healthier lives. However, HAART has also been associated with an increased risk of CVD due to metabolic side effects, such as promoting high lipids and insulin resistance.
What is the clinical presentation of HIV-associated heart disease?
Studies have shown that HIV-infected individuals have a two to fourfold increased risk of CVD compared with uninfected individuals. This increased risk is observed across all age groups but is particularly pronounced in younger adults.
The clinical presentation of HIV-associated CVD is often subtle and non-specific, making diagnosis challenging. Patients may experience symptoms such as chest pain, shortness of breath, fatigue, and exercise intolerance. In some cases, the first manifestation of HIV-associated CVD may be an acute cardiovascular event, such as a “myocardial infarction” or heart attack, or a “cerebrovascular accident” or stroke.
With that, several studies have demonstrated the benefits of cardiac disease screening in HIV patients. For instance, the ARIC study found that carotid artery intima-media thickness, a measure of early atherosclerosis, was significantly higher in HIV-infected individuals compared with uninfected individuals. The impact of HIV on CIMT was similar to that of chronic smoking! This effect is seen even after adjusting for traditional CVD risk factors.
The American Heart Association and the American College of Cardiology recommend that HIV-infected individuals undergo the same CVD screening procedures as uninfected individuals. This includes:
• Blood pressure measurement
• Lipid profile assessment
• Fasting blood glucose test
• Body mass index (BMI) calculation
In addition to these general screening measures, the AHA and ACC recommend that HIV-infected individuals with risk factors such as smoking, hypertension, or diabetes, should undergo more comprehensive CVD screening, including electrocardiogram, echocardiogram, carotid artery ultrasound and stress test on a case-by-case basis.
The frequency of CVD screening in HIV patients should be individualised based on their risk factors and overall health status. However, as a general rule, it is recommended that HIV patients undergo CVD screening at least once every five years.
What is the role of statins in the context of HIV/AIDS and cardiovascular diseases?
Statins, a class of cholesterol-lowering medications, have emerged as a promising strategy to mitigate cardiovascular risk in HIV-infected individuals. Their benefits extend beyond their lipid-lowering properties, encompassing various mechanisms relevant to HIV-associated CVD:
1, Lipid-lowering effect: statins effectively reduce blood levels of “bad cholesterol” or LDL, a major contributor to atherosclerotic plaque formation, thereby delaying heart related complications
2, Anti-inflammatory effect: statins possess potent anti-inflammatory properties, which combat the chronic inflammation seen with HIV infection
3, Immunomodulatory effect: limited studies have shown that statins can favourably affect immune function by reducing immune activation and promoting immune tolerance. This modulation can partially counteract the immune dysregulation associated with HIV infection, further reducing cardiovascular risk
4, Plaque stabilisation: strong research suggests that statins can stabilise atherosclerotic plaques, making them less prone to rupturing and triggering of acute events such as heart attacks or strokes
However, it is important to note that careful consideration of potential drug interactions with certain antiretroviral medications is crucial when prescribing statins to HIV-infected individuals. Close collaboration between HIV specialists, cardiologists and primary care providers is essential in that setting.
To conclude, HIV/Aids is associated with an increased risk of cardiovascular diseases, and this risk has been compounded by the prolonged lifespan of HIV-infected individuals due to HAART. The mechanisms underlying HIV-associated CVD are complex and involve direct viral effects, immune dysregulation, and metabolic abnormalities. Early diagnosis and management of CVD risk factors, including addressing metabolic abnormalities, positive lifestyle modifications and possibly statin therapy, are crucial for improving cardiovascular outcomes in HIV-infected individuals.
• In Observance of Aids World Day: December 1
• Joe Yammine, MD, is a consultant cardiologist at the Bermuda Hospitals Board. The information here is not intended as medical advice or as a substitute for professional medical opinion. Always seek the advice of your physician