by Phyllis Hanlon, Contributing Writer
Pulmonary hypertension, or high blood pressure in the lungs, has been associated with a number of different conditions including heart disease, liver disease, lupus and scleroderma. Research indicates that people with HIV are also at risk for developing PH, a serious condition that affects the heart and lungs. A 2017 study looked at the potential impact of HIV on pulmonary pressures as assessed by a tool frequently used in screening for PH — echocardiography.
An echocardiogram, also referred to as an echo, is an ultrasound of the heart. An echo gives clinicians an estimate of the pressure in the pulmonary artery.
Evan L. Brittain, MD, MSc, of the Vanderbilt Translational and Clinical Cardiovascular Research Center at Vanderbilt University School of Medicine, which is an accredited Pulmonary Hypertension Care Center (PHCC), led a team of researchers in investigating how often elevated pulmonary artery systolic pressure (PASP) occurs in people with HIV infection, the level at which risk of death increases and why this is significant. Other researchers involved in this study also hailed from PHCCs, including the University of Pittsburgh, the University of Utah School of Medicine, Yale University School of Medicine, the University of Washington, the University of Pittsburgh Medical Center and the University of California San Francisco.
The researchers reported that this study included 8,296 patients (2,831 were HIV-positive and 5,465 HIV-negative) who had been referred for echocardiography between 2003 and 2012 and who were registered in the Veterans Aging Cohort Study (VACS). The study compared the patients with HIV to those patients who did not have HIV.
For this study, the authors defined elevated PASP as >40 mmHg as estimated by echocardiography. It is important to note that echocardiography only provides an estimation of PASP levels, and that the only way to directly measure pulmonary artery pressures is through right heart catheterization. PASP is different than the mean pulmonary artery pressure (mPAP) that officially defines PH (mPAP ≥25mmHg). Elevated PASP was found in 782 (27.6%) patients with HIV and in 1,478 (27.0%) HIV-negative patients.
Based upon this definition, the authors found the risk of mortality in veterans with HIV to be higher at all PASP levels when compared to veterans without HIV. Specifically, when the authors compared the veterans with HIV and elevated PASP to the HIV-negative veterans, they found the HIV-positive/elevated PASP group had at least a 50 percent higher mortality rate. They added that HIV-positive individuals in this study had an increased risk, even when PASP was at a lower level that was previously recognized as “normal.” More importantly, they noted that the HIV-positive/elevated PASP group—regardless of other co-existing illnesses, the severity of their HIV (also called viral load) or the type of anti-retroviral medications they were taking—have a higher risk of death. They added that veterans who are African American had a higher prevalence of elevated PASP whether they had HIV or not.
The authors pointed out that not all elevated PASP risk factor profiles are the same. A patient’s HIV status may have an impact, but clinicians should have an understanding of all risk factors so they can make informed decisions about screening and how often to re-evaluate patients with HIV.
Dr. Brittain reported that the findings have important implications for patients with HIV and their health care providers since current guidelines for the general population may or may not apply to this population or others at risk for PH. He noted that the findings should foster reconsideration of current approaches to diagnosing PH, screening and level of oversight in patients infected with HIV.
Dr. Brittain noted that using echocardiography to estimate PASP levels in patients with HIV, especially for those living in geographic areas where HIV prevalence is high and there is little or no access to catheterization labs, may be important for screening, surveillance and risk assessment. Since this study, however, was done in a group that had been referred for echocardiography, the authors could not draw general conclusions on the prevalence of PH among the general HIV population. They neither had data on right ventricular function, which is an important predictive outcome measure in PH, nor did they have data on other risk factors such as methamphetamine or other substance use. And finally, he suggested that if women were included in these studies, the findings could be more representative of the general population. Clinicians should also consider the effects that HIV has on the immune system and what role medications might play.
Vandana Sachdev, MD, senior cardiologist at the National Institutes of Health (NIH), along with two colleagues, wrote an editorial acknowledging that this study provided new insights on the prevalence of elevated PASP in this particular population. However, they asserted that this type of study does not provide results to warrant screening or more aggressive treatments for elevated PASP. Dr. Sachdev indicated that more research on this topic would be welcome, particularly research looking at the causes of death in HIV patients with elevated PASP, and that a “precision medicine approach” would be helpful in explaining risk factors, causes and mortality rates.
Dr. Brittain acknowledged that more study is required to determine how PASP develops in patients with HIV and the reasons for the elevated risk of death.
An American Heart Association (AHA) Fellow-to-Faculty Grant funded the study, and the Department of Veteran’s Affairs, VA Information Resource Center provided data from the Veterans Administration/Centers for Medicare and Medicaid (VA/CMS) for the study.
Each PH patient is different. It is essential that you talk to your own doctor about what treatment options are best for you. For more information on finding a doctor or an accredited care center, visit https://www.phassociation.org/PHCareCenters/Patients.