More heart surgery has been performed on HIV-positive patients since the introduction of HAART, according to Canadian research published in the September 26th edition of AIDS. The study also found that the most significant factor associated with a need for heart surgery was the duration of treatment with antiretroviral drugs, and that since 2000 individuals treated with anti-HIV drugs have become more likely than the age-matched general population in British Columbia to require cardiac surgery.
Investigators in British Columbia conducted a large population-based observation study to describe the trends in heart surgery in HIV-positive patients treated with anti-HIV drugs since 1995. The study also set out to identify social, demographic, clinical and treatment factors associated with heart surgery. Data were obtained from a database which lists all residents of British Columbia treated with anti-HIV drugs since 1992, and a separate database recording cardiovascular interventions.
Of the 5,082 individuals entered in the HIV treatment database since 1995, 63 (1%) were also recorded on the heart surgery database. Consent was obtained from 3,148 of the antiretroviral treated patients, including 44 who had heart surgery, to examine their medical records for the purposes of this study.
The majority of cardiac procedures (70, 72%) were performed since 1999, including 30 instances of open heart surgery, and 31 angioplasties.
After analysis, the investigators established that event rates per 1000 patient for individuals on anti-HIV drugs were 3.37 in 1995, falling to 1.65 in 1996 and 0.34 in 1997, but then rising steeply to 1.57 in 1998, 3.54 in 1999 and 8.18 in 2000.
Adjusted by age the rates per year were 5.25 in 1995, 1.23 in 1996, 0.37 in 1997, 1.72 in 1998, 3.61 in 1999 and 6.52 in 2000. By 2000 this instance had become significantly higher than that seen in the general age-matched British Columbian population.
Of the social, demographic, clinical and treatment characteristics assessed by the investigators, only older age at baseline (median age 45 years versus 37 years, p
The investigators observe, “our data suggest that there is a significantly increasing rate of interventional cardiovascular procedures among HIV-infected individuals undergoing antiretroviral therapy. This trend becomes particularly evident since the widespread introduction of triple drug therapy in 1997”, with HAART treated patients more likely to need a cardiac procedure than than the age matched general population by 2000.
Even after controlling for age, the investigators stress that the duration of anti-HIV therapy was significantly associated with a need for heart surgery. The British Columbian researchers add, “it should be noted that rates of cardiac procedures will probably increase over time, given that people are living longer with HAART and that the population of HAART users is aging.”
Alternative explanations for their findings are suggested by the investigators, including the possibility that HIV itself may be responsible for cardiovascular damage, or that doctors have become more willing to consider HIV-positive patients for heart operations thanks to their improved prognosis. However, the fall in the rates of surgery in 1995 - 1997, when HIV mortality rates were already declining thanks to antiretroviral therapy counters this suggestion.
The investigators conclude that HAART-treated patients should be carefully monitored for cardiovascular risk and that further studies should be conducted to help establish which anti-HIV treatments are particularly associated with cardiovascular problems.
Further information on this website
Heart disease and HAART - overview
The heart - factsheet
Braitstein P et al. Interventional cardiovascular procedures among HIV-infected individuals on antiretroviral therapy 1995 - 2000. AIDS 17: 2071 - 2075, 2003.