A new study from Carle Illinois College of Medicine reveals more Americans than previously estimated have developed a fast, irregular heartbeat that puts them at higher risk for stroke and even death. The research also reveals important gaps in how the condition known as atrial fibrillation (AF or AFib) is treated in the U.S.
In a large, nationwide study of patient records, the CI MED research team found that AFib is more common across the board, in specific regions, and among certain populations than previously projected. “Our analysis demonstrates that the prevalence of atrial fibrillation (at 3.89% nationwide) exceeds prior estimates, underscoring its substantial and growing impact on the U.S. health care system,” said CI MED student Connor Oltman. He led the study involving 4.8 million patient records from between 2019 and 2023 under the guidance of Clinical Sciences Professor Issam Moussa, MD, the study's senior author.
Atrial fibrillation is an irregular, often rapid heart rhythm that can lead to stroke if left untreated. It’s an important, growing health concern because its prevalence in the U.S. is projected to double between 2010 and 2030, as the population ages. One in three patients with AFib will experience a stroke in their lifetime, and the condition is strongly linked to an increased risk of heart disease and death.
Age: AFib risk increases with age. The CI MED team found that the incidence nearly doubled among patients in their 70s versus those in their 80s. Of the patients in the study who were 90 or older, nearly one in four had an AFib diagnosis.
Demographics: Other demographic groups showing an increased risk for AFib include males, non-Hispanic white patients, people living in rural areas, those with low socioeconomic status, people with a variety of other health problems, and those with a family history of AFib.
Location, location, location: The study tapped into records accessed through the Epic Cosmos electronic health record database to offer new insight into where AFib is more common. “Prior studies estimated the national prevalence of atrial fibrillation using regional databases or small but well-defined cohorts. Using a comprehensive national dataset, we identified significant geographic variations in AF prevalence,” he said.
Among the geographic patterns revealed in the data was an increased incidence of AFib in the Midwest, South, and Northeast regions. Rates were highest in the states of Nebraska (6.94%), Maine (5.5%), and Rhode Island (4.99%) while Utah, Colorado, and Nevada had the lowest incidence of AFib. “This is likely influenced by regional differences in health care access, population demographics, and comorbidity patterns,” Oltman said.
Conditions in Younger Patients: One surprising finding was the high level of additional health problems found in younger patients with AFib. “While individuals over 65 with AF showed only a moderate increase in comorbidities compared to their non-AF peers, patients under 65 with AF had a significantly higher increase in underlying comorbidities compared to their non-AF counterparts,” Oltman said. Common co-occurring conditions, other than heart disease, include high blood pressure, diabetes, abnormal lipid levels in the blood, chronic kidney disease, chronic obstructive lung disease, peripheral vascular disease, and obstructive sleep apnea. “Consequently, the management of AF in this younger demographic warrants more vigilant monitoring and intervention,” he said.
Treatment Gaps: Standard treatments for AFib include different medications that regulate the heart rate, the heart rhythm, and thin the blood to avoid clots that can lead to strokes. Doctors also use procedures to restore a normal heart rate and rhythm and reduce stroke risk.
While about 81% of the AFib patients in the study were treated for a high heart rate, nearly a third of patients went untreated with anticoagulants that target clotting risk. Some people can’t tolerate these anti-clotting drugs because of bleeding risks, but they remain the gold standard treatment for clot prevention in patients with AFib.
Moussa, who is an interventional cardiologist and clinical sciences professor, says the evidence is clear that anticoagulation therapies and interventional alternatives are underused nationally. “Our findings represent a call to action with regard to the development of robust systems of care to monitor and encourage compliance with anticoagulant therapy, as well as community-based education regarding the role of left atrial appendage closure in patients who qualify for this therapy,” Moussa said. LAA closure is a catheter-based procedure that offers an alternative to anticoagulants by sealing off a part of the left atrium to prevent blood pooling and clot formation.
Oltman said the team’s future work will explore why so many patients who might benefit from anticoagulants don’t take them and how AFib differs in patients across age groups. “Understanding these differences could open pathways for age-specific interventions and preventive strategies tailored to each patient demographic,” he said.
Editor’s notes:
In addition to Oltman and Dr. Moussa, other members of the research team include CI MED students Taehyung Peter Kim, James W.Y. Lee, John D. Lupu, and CI MED Assistant Professor of Biomedical and Translational Sciences Ruoqing Zhu.
Dr. Issam Moussa is a professor of medicine at CI MED and the director of the Heart and Vascular Institute at Carle Foundation Hospital in Urbana.
The study is published in the Journals of the American College of Cardiology, November 2024 edition, available here.