Proponiamo un editoriale di BMJ che esorta i clinici ad iniziare le terapia antiretrovirale nei pazienti naive vicino a valori di CD4 di 200 cells/mm3 per tenere in dovuta considerazione il rischio cardiovascolare. Questo permetterebbe alle persone di fare dei cambiamenti dello stile di vita, possibilmente assumere farmaci che abbassano i livelli di lipidi, in modo da ridurre il rischio cardiovascolare. Tuttavia, in questa sede, evidenziamo che molti immunologi invece mettono in guardia sul rischio di iniziare una terapia antiretrovirale troppo tardi, ossia a valori di CD4 troppo vicino alle 200 cells/mm3.
An editorial published in the June 11th issue of the British Medical Journal argues that HIV clinicians should take cardiovascular disease risk into account, in addition to the risk of HIV progression, before suggesting that treatment-naive individuals begin highly active antiretroviral therapy (HAART).
If the cardiovascular disease risk is greater than 20% over ten years, Filip Moerman and his colleagues from Antwerp and Ghent in Belgium advocate that HAART be delayed until an individual’s CD4 count is close to 200 cells/mm3. Waiting until the lower limit of current guideline thresholds, rather than starting therapy near the upper range of 350 cells/mm3, would allow time for individuals to undertake lifestyle changes – and possibly take lipid-lowering medication – in order to reduce the risk of cardiovascular disease.
The latest British HIV Association (BHIVA) HIV treatment guidelines – due to be published in HIV Medicine in July and currently available in draft form on the BHIVA website – acknowledge an “increased cardiovascular risk associated with drug induced metabolic abnormalities”, and for the first time include an algorithm for the management of lipodystrophy. This includes monitoring for cardiovascular disease risk prior to initiating or changing HAART, as well as a yearly assessment for those on stable HAART. However, the guidelines do not specifically recommend delaying the initiation of HAART if there is a concern over higher-than-usual cardiovascular disease risk.
However, Moerman and colleagues argue that although the decision to start HAART is currently based on CD4 count, a cardiovascular risk profile prior to HAART initiation should also “inform timing and choice of regimen for HAART.”
They suggest using the Framingham risk score to predict the ten-year absolute risk of a coronary heart disease event. “When the Framingham risk scale is used, a score of 23 for women and 15 for men corresponds with a 20% risk over ten years of developing coronary heart disease,” they write. “In this particular population, lifestyle changes (and eventually lipid lowering drugs) could substantially reduce the risk of coronary heart disease, but it has to be borne in mind that the cumulative risk of acquiring an AIDS defining event does not increase if HAART is postponed until a CD4 T lymphocyte cell count of 200 [cells/mm3] is reached.”
Delaying HAART until a CD4 count of 200 cells/mm3 “could easily [mean] two or five years” to allow those at risk to reduce their cardiovascular disease risk through lifestyle changes “such as smoking cessation, salt restriction, and physical activity,” they write. “Furthermore, during the years of delay, new treatment options might come into life that carry less risk for cardiovascular disease.”
They add that medically managing cardiovascular risk factors once an individual is on HAART “gives rise to other problems related to HIV and HAART, such as an additional pill burden, which may impair adherence and lead to increased resistance.”
The editorial concludes by suggesting that initiating HAART “remains a decision that implies an individual and a holistic approach. A high cardiovascular risk score warrants that treatment is delayed if needed until the lower threshold of 200 [cells/mm3] is reached. Implementing cardiovascular risk reduction before the start of HAART, as well as for patients already taking HAART, deserves our attention in an era when we become more and more concerned with the long-term side-effects of HAART.”
Moerman F et al. Highly active antiretroviral therapy: cardiovascular risk needs to be assessed before starting treatment. BMJ 330:1341-1342, 2005.