A new Northwestern Medicine study published in Circulation Heart Failure has found almost half of U.S. adults with heart failure have poorly controlled hypertension and diabetes — two common conditions among patients with heart failure.
The latest 2022 guidelines for the management of heart failure recommends control of these key risk factors. Doing so can reduce hospitalizations and help patients live longer, the study authors said.
This study is the first to ascertain how well hypertension and diabetes are controlled in a nationally representative sample of people living with heart failure. It found 48 percent of people living with heart failure, who represent 2.3 million U.S. adults, had uncontrolled hypertension, which the scientists defined as a systolic blood pressure of greater than 130 mm Hg.
Defining heart failure
Heart failure occurs when the heart can't pump optimally and fails to deliver enough oxygen to the body, making it harder for people to perform everyday tasks. It affects more than 6 million people in the U.S., especially those who have other heart problems or who have had heart attacks. Congestive heart failure usually happens slowly over time and is caused by fluid overload, which results in shortness of breath and swelling in the abdomen or legs.
Blood pressure control has been declining
Even in people who don't have heart failure, there has been a worsening in control of blood pressure in the last 10 years, said senior author Sadiya Khan, MD, MSc, assistant professor of Medicine in the Division of Cardiology. This problem has only grown during the COVID-19 pandemic.
The reason we wanted to do this study is because, unfortunately, mortality related to heart failure has increased in recent years. Our thought was, perhaps, this was an area in which optimal care for health care is achievable, but in fact it's quite dismal and represents a big implementation gap in health care."
Sadiya Khan, MD, MSc, Northwestern Medicine physician
Racial and ethnic disparities
The prevalence of uncontrolled blood pressure was higher among non-Hispanic Black adults than their white peers, at 53 percent compared to 47 percent, the study found.
Khan said this disparity was not surprising, as it mirrors racial disparities in blood pressure control in the general population.
"This speaks to a larger problem, which is a systemic failure to control the leading risk factors that account for the greatest number of non-communicable deaths worldwide," Khan said.
While the vast majority of people in the study had insurance, they also reported incomes below the poverty line, which could affect their access to quality care or the ability to pay for medications, Khan said.
"The reasons for these disparities are manifold," said lead author Leah Rethy, MD, a resident physician at the University of Pennsylvania Perelman School of Medicine. They include the history of structural racism in the U.S., which is largely responsible for disparities in access to health care, proximity to green spaces where people can safely meet exercise goals and "all sorts of things that influence somebody's life course up until the time they get heart failure," she said.
Theorizing why risk factors are uncontrolled
While the study didn't examine why there is an "unacceptably" high prevalence of uncontrolled blood pressure and glucose rates among patients with heart failure, the scientists have some theories.
They said they believe there is a lack of awareness and understanding of the importance of managing blood pressure in this high-risk group. There also is a lack of accessibility to consistent and affordable primary and specialty care for adults with heart failure, particularly those under age 65 who don't qualify for Medicare.
Many people who have heart failure are older, frail and may have cognitive issues, Rethy said, so it may be difficult for them to perform the extensive self-monitoring needed to manage their health.
"A lot is put on patients to manage this at home, and it's a challenge," Rethy said.
The key is finding ways to help health care professionals and patients put into practice what researchers know about how to get blood pressure and blood glucose levels under control.
"There are many good medications and lifestyle interventions that we know work," Rethy said. "We shouldn't think of it as too lofty to achieve. We have access to lots of tools to help fix it."
How the study was conducted
Using 2001-2018 data from the U.S. Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey, the scientists evaluated the prevalence of uncontrolled blood pressure and glucose levels in non-Hispanic Black, non-Hispanic white and Mexican-American adults 21 years old and up with self-reported heart failure.
The study did not track whether people being treated for high blood pressure and diabetes were actually taking the medications prescribed to them.
Rethy, L., et al. (2022) Blood Pressure and Glycemic Control Among Ambulatory US Adults With Heart Failure: National Health and Nutrition Examination Survey 2001 to 2018. Circulation: Heart Failure. doi.org/10.1161/CIRCHEARTFAILURE.121.009229.