16 March 2015
Survival after surgery with HIV
In Canada and other high-income countries, the widespread availability of potent combination anti-HIV therapy (commonly called ART or HAART) has had a tremendous impact on the health of HIV-positive people. Since 1996, deaths due to AIDS-related infections have plummeted. Furthermore, researchers increasingly expect some HIV-positive people who take ART to live into their 80s. As HIV-positive people get older, like the rest of the population they may require surgery.
Focus on surgery
Before ART became available reports suggested that HIV-positive people had generally poor results after surgery. Specifically, this population was more likely to develop serious infections and had a higher risk of death compared to HIV-negative people who also underwent surgery.
In many high-income countries, HIV infection is relatively uncommon—found in less than 1% of the population. This has made it difficult to monitor any changes in what a team of Yale University researchers calls “changing patterns of surgical outcomes” in this population from one hospital or even one region.
To overcome this challenge, a team of researchers at Yale University and elsewhere in the U.S. reviewed information collected in databases held by the Veterans Health Administration. They restricted their review to data captured between 1996 and 2010. They compared rates of death after surgery among HIV-positive and HIV-negative people, focusing on the first 30 days after surgery. This is a crucial period for all surgeries.
The researchers found that HIV-positive people had “relatively low rates” of death within the first 30 days after surgery. The CD4+ count of HIV-positive participants was a major factor that affected their survival—higher cell counts prior to surgery were associated with a decreased risk for death. The researchers also found that other factors, including the amount of protein in the blood and a person’s age, had an important impact on post-surgical survival. Taking all of their data into account, the researchers were able to propose several scenarios of the risks that HIV-positive patients might face after surgery in the future. Such information will be useful for both surgeons and patients.
Researchers accessed databases that held information on 132,540 people, of whom 44,180 were HIV positive. They randomly selected participants who had undergone common surgical procedures, matching each HIV-positive person to two HIV-negative people of similar age, race and gender. Participants were distributed as follows:
- 1,641 HIV-positive ART users
- 3,282 HIV-negative people
The average profile of participants was as follows:
- age – 54 years
- 99% men, 1% women
- main ethno-racial groups – white 44%; black 46%
- some co-existing health conditions included: higher-than-normal blood pressure, hepatitis C virus co-infection, type 2 diabetes, coronary artery disease and cancer
The following is a list of some relatively common surgeries performed on study participants:
- removal of the gallbladder
- hip replacement
- spinal operations
- hernia repair
- coronary artery bypass
- removal of part of the colon or rectum
- amputation of the legs, feet or toes
In general, researchers found that the lower an HIV-positive person’s CD4+ count just prior to surgery, the greater their risk of death. The risk of death among HIV-positive people compared to HIV-negative people was as follows:
- CD4+ count greater than 200 cells/mm3 – an almost two-fold increased risk of death
- CD4+ count from 50 to 199 cells/mm3 – an almost three-fold increased risk of death
- CD4+ count less than 50 cells/mm3 – a six-fold increased risk of death
Albumin is a protein found in blood. Less-than-normal levels of albumin can occur in a number of serious conditions, including malnutrition, intestinal problems, kidney injury, liver injury and so on. Researchers found that 28% of all participants (regardless of HIV status) had low albumin levels prior to surgery. This condition is called hypoalbuminemia. According to the researchers, low levels of albumin had a greater impact on post-surgical survival than “all but the lowest CD4+ cell count mark of less than 50 cells/mm3.” In other words, low albumin levels had a negative effect on survival.
Age and CD4+ count
The age of participants also had a major impact on survival. Here are some examples given by the researchers to underscore the effect of age:
- An HIV-positive person with a CD4+ count greater than 200 cells/mm3 had the same post-surgical risk of death as an HIV-negative person who was 16 years older.
- An HIV-positive person with a CD4+ count from 50 to 199 cells/mm3 had the same post-surgical risk of death of an HIV-negative person who was 25 years older.
- An HIV-positive person with a CD4+ count less than 50 cells/mm3 had the same post-surgical risk of death as an HIV-negative person who was 47 years older.
These examples emphasize the importance of optimizing care and HIV treatment so that CD4+ cell counts are relatively high prior to surgery.
Now and in the past
The research team commented that the overall death rate among HIV-positive people in the study was 3.4% (compared to 1.6% among HIV-negative people) and they described this as “relatively low” compared to reports from the time before ART was available.
Bear in mind
The current study was retrospective in design. That is, it reviewed data collected in the past for another purpose. Such study designs may inadvertently arrive at biased conclusions when interpreting data. To the research team’s credit, they at least were able to randomly select participants who had similar surgeries, which should greatly help reduce the potential for bias.
A major issue with the study is that participants were overwhelmingly male.
The researchers stated that based on their results, “[doctors] and patients should consider HIV infection and CD4+ cell counts as just two of many factors associated with surgical outcomes that should be incorporated into surgical decision-making.”
For the future
The present study lays a good foundation for future work in understanding the impact of surgery on the health of HIV-positive people. The researchers suggest that a future study on post-operative complications—focusing on heart attacks, infections and health-related quality of life—would be of interest to both surgeons and their patients.
—Sean R. Hosein
King JT Jr, Perkal MF, Rosenthal RA, et al. Thirty-day postoperative mortality among individuals with HIV infection receiving antiretroviral therapy and procedure-matched, uninfected comparators. JAMA Surgery. 2015; in press.