Chicago, IL - Physicians treating people who are HIV positive still underestimate the increased risk of cardiovascular disease in this group, according to a group of HIV and CVD experts who participated in a joint conference in June 2007, organized by the American Heart Association and the American Academy of HIV Medicine.

According to meeting chair, Dr Steven Grinspoon (Harvard Medical School, Boston, MA), underawareness of cardiovascular risk is prevalent among HIV physicians and cardiologists alike.

"These patients, thankfully, are living longer overall due to the HIV meds we have today; it is a chronic disease," he said. "There needs to be recognition among both HIV clinicians and cardiologists that first, these patients are at risk for cardiovascular disease and, second, we need to recognize that risk and figure out what we need to do to treat it."

The conference proceedings, including an executive summary [1], have been published online in Circulation and in the Journal of Acquired Immune Deficiency Syndrome.

Experts who participated in the meeting emphasize that while antiretroviral therapy is largely responsible for improving and extending the lives of people with HIV, the drugs also appear to increase the risk of cholesterol abnormalities, pulmonary hypertension, and pericardial disease in a group that already has a higher prevalence of other common risk factors for CVD. Indeed, one of the points made by Grinspoon et al in the executive summary is that researchers do not know the relative contribution to CVD of the drug therapy vs the underlying disease.

Several recent studies have suggested that traditional risk factors, such as dyslipidemia, hypertension, and diabetes, likely only account for 25% of the excess risk in HIV-positive individuals. "But there are also some nontraditional risk factors, like inflammation, that may be responsible for an even greater proportion of CV risk in these patients," Grinspoon told heartwire. "It became apparent to people at the conference that this is probably a very complicated interplay between risks that were brought about via the adverse effects of the anti-HIV drugs and also risks of the virus itself."

Another point emphasized during the meeting is that while some research, including the large DAD study, has underscored the cardiovascular risks associated with HIV medications, other research, including the SMART study, suggested that HIV-positive patients who stayed on their HIV medications did better than people who stopped or who took their medication less consistently.

"How do you put those two things together?" asked Grinspoon. "I think we came to an agreement during the conference that it's because there's multiple etiologies, multiple mechanisms. While there are risks associated with the use of these drugs, the meds also have a positive effect by keeping down inflammation and other things related to the virus and actually improve the cardiovascular situation."

Related to this, Grinspoon and colleagues highlighted the need for collaboration between medical specialties. "In another context where someone developed a side effect to a drug, you just change the drug," Grinspoon explains. "But it's not that easy in HIV-infected patients, because resistance can develop if you fool around with these medications. HIV doctors need to understand this, and the cardiologists need to work with the HIV doctors, because you need a team to manage this."

Overall, however, MI risk in HIV-positive subjects is 70% to 80% higher than that of non-HIV-positive people, and these statistics have been seen across several studies, Grinspoon et al note.

Moreover, they agreed that physicians can and should use the Framingham Risk Score or other existing risk-stratification algorithms to calculate the risk of CVD in someone with HIV, but that the development of a risk calculator that takes HIV-related factors into account should be a research priority.

"If nothing else, if this conference brings to light the fact that HIV doctors and cardiologists should just use the existing algorithms in patients with HIV to estimate CV risk, that would be a victory," Grinspoon said.

The cholesterol effects of HIV and its treatment tend to be low HDL and high triglycerides, the summary explains. Other risk factors commonly seen in people with HIV that may or may not be influenced by antiretroviral therapy include insulin resistance, diabetes, abdominal fat, and kidney abnormalities.

But people with HIV also seem to have a higher prevalence of risk factors seemingly unrelated, at least directly, to their HIV status. For example, several studies have suggested that 50% or more of HIV-infected individuals are smokers. Grinspoon also highlighted to heartwire a recent paper by Joy et al [2] indicating that HIV-positive individuals tend to eat more fat and more "bad" fats than people who are not HIV-positive. The smoking and poor eating habits may be a throwback to a time when an HIV diagnosis was a death sentence, something Grinspoon emphasized was really no longer the case.

"What people don't realize is that one of the top killers in people with HIV is cardiovascular disease. Back when people were dying of HIV and the meds weren't working, the last thing in the world people wanted to focus on was their cholesterol. But now, if people are going to live, and they're going to live a long time, we have to get more aggressive about managing the cardiovascular consequences."

Dr James Stein (University of Wisconsin, Madison), who chaired a session on CHD prevention during the HIV/CVD conference, pointed out that lifestyle changes were also a focus of the meeting.

"Lifestyle interventions have not been emphasized as much in patients with HIV as in the general 'at-risk' adult community," he pointed out to heartwire. "It also is important that HIV care providers and patients with HIV understand the importance of CVD prevention in HIV patients and the importance of identifying and treating CVD risk factors."

Like Grinspoon, Stein also underscored the need for close collaboration between specialists. "Cardiologists need to be aware that there are a myriad of drug interactions between antiretroviral medications and commonly used cardiovascular medications, including lipid-lowering therapy, antihypertensive therapy, and antiarrhythmic medications.  The complexity of HIV disease and its treatment truly calls for a multidisciplinary approach to its management," he said.