by Christine Yu, Pennsylvania State University

Credit: CC0 Public Domain

Every year, nearly 800,000 people have a stroke in the United States, and it is the fifth-leading cause of death and the most common cause of permanent disability. More than 80% of strokes are ischemic strokes, most often caused by narrowing or a blockage in the carotid arteries in the neck—the primary blood vessels that supply blood to the brain—restricting blood flow to the brain. While carotid endarterectomy, a surgical procedure to remove plaque from the carotid artery, has been shown to reduce the risk of stroke, not all patients experience the same outcomes, according to a new study led by researchers from the Penn State College of Medicine.

The team analyzed findings from previously published studies over the last 25 years and found that compared to white patients, non-white patients are at twice the risk of dying within 30 days of a carotid endarterectomy. The study highlights persistent differences in medical outcomes based on race, despite advances in research, education and clinical practice.

The findings were published in the Journal of Vascular Surgery. According to the researchers, the study is the first meta-analysis—meaning it examines data from previously published studies—to determine the influence of race on carotid endarterectomy outcomes, and with data from over half a million patients, it's one of the largest studies within the carotid artery surgery research literature.

"Twice the risk is a big risk," said Ahsan Zil-E-Ali, research fellow in the Heart and Vascular Institute at the Penn State College of Medicine and first author of the study. "The fact that this increased risk is the same throughout the studies over the years surprised our group. Why are we not able to fix this problem?"

Health disparities are preventable differences in health outcomes between groups that stem from social and economic inequities. Disparities can refer to measures like life expectancy, the prevalence of a disease or condition and health status.

Carotid endarterectomy is a frequently performed and well-studied procedure. Disparities in surgical outcomes for the procedure were first reported approximately 30 years ago, explained Zil-E-Ali. The research team was interested in answering two primary questions—how has the risk of mortality and stroke after carotid endarterectomy changed over time and how does the risk compare between white and non-white patient populations?

The team performed a systematic review and meta-analysis, gathering evidence from 12 previously published research papers and synthesizing the outcomes data from 574,055 patients who underwent a carotid endarterectomy procedure from 1998 to 2022. They found that non-white patients have twice the risk of dying within 30 days of the procedure compared to white patients. They did not find a significant relationship between race and the risk of stroke in the studied timeframe.

"When we think of disparities, we consider differences between groups, but we shouldn't ignore inequities, which are a much bigger problem," Zil-E-Ali said. "If someone in their 30s or 40s, unaware of preventative measures, has never visited a doctor and ends up in the emergency room, that person may already be in an advanced stage of the disease. While a surgeon can address the immediate issue, the underlying problem is far larger than just one procedure."

Surgery is just one point on the spectrum of care of medical management within a larger health care system. There are myriad factors, like geographic location, insurance coverage and socioeconomic status, that may contribute to structural inequities that may lead to disparities in access to care, the quality of care delivered, and ultimately, surgical outcomes, the researchers explained. These factors can contribute to characteristics associated with higher mortality like advanced disease, late access to care or prescription medication, lack of postoperative care and follow-up.

"We've always had a suspicion that people from different racial backgrounds seek care at different stages of disease with non-white patients seeking care in the later stages of disease progression, which may influence outcomes," said senior author Faisal Aziz, Elsie H. Sealfon professor and chief of vascular surgery at the Penn State College of Medicine. "This paper confirms what we see in the clinic."

The team members said they hope to build on this research and look at data on disparities in other vascular conditions and diseases.

Other Penn State College of Medicine authors include medical students Billal Alamarie, Abdul Wasay Paracha and Fadi Samaan.

More information: Ahsan Zil-E-Ali et al, Systematic review and meta-analysis to assess the racial disparities in the outcomes of carotid endarterectomy in the United States, Journal of Vascular Surgery (2024). DOI: 10.1016/j.jvs.2024.05.034

Journal information: Journal of Vascular Surgery 

Provided by Pennsylvania State University