Smoking Almost Triples Heart Attack Risk in Those Living With HIV

People living with HIV are significantly more likely to smoke or have smoked than those who are HIV negative, studies have shown. Moreover, previous studies have reported that being HIV positive almost doubles a person's risk for having a heart attack (myocardial infarction, MI).

The link between HIV, smoking and heart attacks was even more striking, with the risk of a heart attack almost three times greater in HIV-positive smokers than in HIV-negative ones, according to a recent Danish study published in Clinical Infectious Diseases.

But at the same time, an analysis of Kaiser Permanente managed health care program data saw the heart attack risk among its HIV-positive members fall to the same level as its HIV-negative members between 1996 and 2011.

High Risk of Heart Attacks Among HIV-Positive Smokers in Denmark

Researchers in Denmark compared data on 3,251 patients living with HIV with 13,004 individuals of the general population over a period of 18 years (1995-2013). Forty-seven percent of those with HIV currently smoked, while only 19% of those without HIV did so.

When matched by age, gender and other demographic characteristics, current HIV-positive smokers were almost three times more likely (incidence rate ratio [IRR] of 2.83) to experience a heart attack when compared to those without HIV who currently smoke. Looking only at those living with HIV, current smokers were six times as likely to suffer a heart attack than those who do not smoke (IRR 6.06).

These numbers caused the study authors to estimate that 72% of heart attacks in HIV-positive persons are caused by smoking compared to 24% of heart attacks in HIV-negative individuals. M. John Gill and Dominique Costagliola dispute that number in a commentary on the study, but advise HIV practitioners that "seizing every opportunity during HIV care delivery to focus our efforts to reduce the high rate of tobacco smoking offers the greatest potential for reducing MI rates."

Falling Heart Attack Rates Among People Living With HIV in California

Kaiser Permanente, meanwhile, reports that in 1999 its HIV-positive members were twice as likely to suffer a myocardial infarction than its HIV-negative members. However, by 2011, the risk of having a heart attack did not differ based on HIV status. The analysis was based on data from 24,768 HIV-positive and 257,600 HIV-negative program members.

Researchers believe this decline is due to a greater emphasis on smoking cessation programs, improved antiretroviral medications with fewer cardiovascular side effects, earlier start of HIV treatment and the higher use of lipid-lowering drugs.

"Our findings lend support to the concept that increased MI risk for HIV patients is largely reversible with continued emphasis on primary prevention in combination with early initiation of [antiretroviral therapy] to preserve immune function," they concluded.