The risk of heart attack among people with HIV is linked to a depleted immune system, specifically if CD4s dip below 200, aidsmap reports. Similarly, keeping CD4s at or above 500 means no greater risk for heart attack when compared with HIV-negative controls. Publishing their findings in the Journal of Acquired Immune Deficiency Syndromes, investigators conducted a case-controlled study of 22,081 people with HIV who were matched with 230,069 HIV-negative controls, all of whom received care through the Kaiser Permanente California health plan between 1996 and 2009.

With a mean 4.5 years of follow-up and 99,090 person years provided for analysis, the HIV-positive group experienced 283 heart attacks, for an incidence of 283 per 100,000 person–years. With a mean 5.4 years of follow-up and 1,253,550 person-years provided for analysis, the HIV-negative group experienced 2,064 heart attacks, for an incidence of 165 per 100,000 person-years.

After controlling for various factors, the researchers found that HIV on the whole was linked to a 44 percent increase in the likelihood of heart attack compared with HIV-negative controls. Those people with HIV who were taking antiretrovirals had a 50 percent increased risk of heart attack when compared with the controls.

Those HIV-positive people with either a current CD4 level below 200 or whose lowest-ever CD4 count dropped below this number had a respective 76 and 74 percent greater likelihood of heart attack when compared with the HIV-negative group. Those who never experienced a CD4 count at or below 500 had no greater risk of heart attack than the control group.

To read the study, click here.

To read the aidsmap story, click here.