People with uncontrolled HIV infection are significantly more likely to suffer heart failure than people without HIV infection, according to results of a large cohort study of US military veterans published this week in Archives of Internal Medicine.
The study adds to the accumulating evidence that untreated HIV infection may increase the risk of heart disease.
Heart failure is a gradual weakening of the heart that leads to increasing breathlessness and weakness, and requires medication or surgery as the condition becomes more severe.
Previous studies have looked at myocardial infarction, stroke or other cardiovascular events. Heart failure is a cardiovascular outcome that may occur for a variety of reasons, including heart attack, high blood pressure, disease of the heart muscle (cardiomyopathy), alcohol or cocaine abuse, and represents a progressive condition that requires active management rather than a one-off event.
The study evaluated heart failure in a large cohort of male US military veterans, and excluded anyone with pre-existing cardiovascular disease or cancer.
A total of 8,846 participants were evaluated, of whom 28.2% were HIV-infected. All participants were part of the Veterans Aging Cohort Study Virtual Cohort.
Participants had a median age of 48 years, and around 39% were African-American.
With regard to risk factors for heart disease those with HIV were more likely to smoke (55% vs 45%, p<0.001), to have a history of cocaine use (21.9% vs 15.7%, p<0.01) or hepatitis C coinfection (30.5% vs 11.4%, p<0.001). HIV-negative participants were more likely to have diabetes (24.8% vs 16.7%, p<0.001) or hypertension (28.8% vs 18.7%, p<0.001).
Rates of alcohol dependence and elevated lipid levels were similar in the two groups, but HIV-positive people had a lower mean body mass.
People with HIV infection were almost twice as likely to experience heart failure (incidence 7.2 vs 4.82 per 1000 person-years of follow-up, hazard ratio 1.81, 95% confidence interval 1.39-2.36).
Among individuals without chronic heart disease or a history of alcohol abuse HIV was second only to hypertension as a risk factor for heart failure, and tended to show a stronger association with heart failure than traditional risk factors such as smoking, high body mass and older age.
Individuals who had a detectable viral load on recruitment to the cohort (HR 2.28 vs HIV-uninfected), or who subsequently experienced viral load rebound after joining the cohort (HR 2.39), had a significantly higher risk of heart failure than those who had an undetectable viral load throughout their follow-up time in the cohort (HR 1.10) (p> 0.01 and >0.03 respectively).
The authors say that their analysis is limited in its ability to fully quantify any effects of antiretroviral treatment by lack of data on antiretroviral drug regimens and adherence.
The authors suggest that ongoing HIV replication is an important risk factor, but also note that secondary infections of the myocardium (heart muscle) by opportunistic pathogens present in people with HIV, such as cytomegalovirus, Toxoplasma gondii and Cryptococcus neoformans could be responsible for some portion of heart failures.
They say that traditional risk factors for heart failure should not be ignored in people with HIV infection. Age, obesity, hypertension, diabetes, alcohol abuse and African-American race all remained significant predictors of heart failure even after individuals with chronic heart disease were excluded from the analysis, suggesting the extent to which modification of lifestyle factors is advisable in advance of any development of symptomatic heart disease.
“Interventions to minimize the modifiable traditional risk factors, including glycemic and blood pressure control, weight reduction and abstinence from alcohol are prudent strategies that should be emphasized,” the authors conclude.
They say more work is needed to determine whether heart failure in persons with HIV is chiefly systolic or diastolic, and to look at the effects of interventions such as glycemic control and anti-hypertensive medication on the risk of heart failure.
Butt AA et al. Risk of heart failure with human immunodeficiency virus in the absence of prior diagnosis of coronary heart disease. Arch Intern Med 171: 8, 737-43, 2011.