Heart Attacks in HIV Often Not Due to Atherosclerosis: A Top HIV Clinical Development of 2017
It is well known that people living with HIV have relatively higher rates of cardiovascular disease (CVD). Whether this increased risk is due to the persistent inflammation caused by HIV, certain HIV medications, someone having more traditional factors associated with CVD, or one or more of the above is unclear. In response, there has been a push for clinicians to assess CVD risk and, to reduce the risk of atherosclerosis, apply interventions including dietary and lifestyle modifications and treatment with statins. However, an analysis conducted by Crane and colleagues within the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) Cohort suggest that many myocardial infarctions (MI) occurring in people living with HIV might not fit this typical paradigm.
Across the eight CNICS sites in the U.S., almost 27,000 HIV-positive patients were evaluated and 1,689 met criteria for at least one potential MI, for a total of 2,037 events. Of these events, 571 were adjudicated by designated reviewers as a definite or probable MI. Among these, 49.6% were what is categorized as a Type 1 MI, which is due to atherosclerotic plaque and is what we typically think of when an MI occurs. Another 79 events did not meet MI criteria but had an intervention for atherosclerosis, such as a coronary stent. However, 50.4% of the adjudicated MIs were Type 2 MI events, which are MIs secondary to atherosclerotic plaque rupture, due to causes including hypotension, hypoxia, and stimulant-induced spasm, resulting in increased oxygen demand or decreased supply.
Compared with the Type 1 MI patients, those with Type 2 MIs were younger, female, African American, not receiving antiretrovirals (so, lower CD4 cell counts and higher viral loads), and had a history of injection drug use. The Type 2 MI patients had a significantly lower 10-year risk for coronary heart disease. Interestingly, sepsis or bacteremia, vasospasm due to cocaine, and hypertensive emergency were the most commonly identified causes of the Type 2 MIs.
The Bottom Line
In the general population, the lion's share of MI is Type 1. In this large cohort of HIV-positive people, Type 1 and Type 2 MIs were evenly split. This finding speaks to how people living with HIV might be distinctive in terms of lifestyle and risk for medical conditions that are not necessarily always related to their HIV. Moreover, if confirmed in other studies, the approach to MI prevention and care in the setting of HIV might need to be reconsidered as it might differ by MI type. Certainly, the main messages of smart eating, exercise, smoking cessation, and getting lipid levels to target remain very relevant. However, we need to learn how to better identify and manage an alternative MI pathway that might require very different interventions and that strikes those who might not seem at risk.
What are some other top clinical developments of 2017? Read more of Dr. Wohl's picks.
David Alain Wohl, M.D., is a professor of medicine in the Division of Infectious Diseases at the University of North Carolina (UNC). He is site leader of the UNC AIDS Clinical Trials Unit at Chapel Hill, director of the North Carolina AIDS Education and Training Center (AETC), and co-directs HIV services for the North Carolina state prison system. In 2014, he became co-director of the UNC-Duke Clinical RM Ebola Response Consortium.