Atrial Fibrillation in Young Adults: Increased Heart Failure and Stroke Risk

In a recent study published in Circulation: Arrhythmia and Electrophysiology, a team of researchers explored the burden of risk factors (RFs), clinical outcomes, and long-term survival among patients under 65 years old with atrial fibrillation (AF).

Background Atrial fibrillation (AF), the most prevalent cardiac arrhythmia in the United States (U.S.), affected approximately 5.2 million individuals in 2010, with projections anticipating an increase to 12.1 million by 2030.

While AF traditionally affects older adults, a growing percentage of patients are diagnosed before the age of 65, constituting 10%-15% of cases. This age group encounters escalating rates of risk factors such as hypertension, diabetes, and obesity.

Despite its prevalence, the impact of AF on mortality and major clinical events in younger patients remains inadequately defined. Further investigation is necessary to elucidate distinct clinical outcomes and effective management strategies for younger individuals with Atrial Fibrillation.

Explore the Cardiology In-Person Conferences and Online Courses to stay updated with the latest advancements in cardiology.

About the Study

The study was a retrospective observational cohort analysis conducted at the University of Pittsburgh Medical Center, involving patients over 18 years old diagnosed with AF.

Diagnoses were confirmed using International Classification of Diseases (ICD), Ninth and Tenth Revision codes. Patients evaluated between January 2010 and December 2019 were included if they had at least two outpatient visits in internal medicine, family medicine, or cardiology.

Data were retrieved from a comprehensive electronic health record system in combination with administrative and other data sources. This study examined a variety of cardiovascular risk factors and comorbidities, including obesity, smoking history, hypertension, diabetes, and various cardiac conditions. Detailed information on patient characteristics such as age, gender, and race was collected, along with data on prior cardiovascular interventions and medication usage at baseline.

The primary outcome measured was all-cause mortality, confirmed through the Social Security Death Index and supplemented by electronic health record data. Secondary outcomes included hospitalizations for cardiovascular events and cardiac interventions occurring during follow-up.

Statistical analyses included various tests to compare continuous and categorical variables and utilized Kaplan-Meier survival analysis and Cox proportional hazards models to explore the impact of AF on mortality in patients under 65, adjusting for multiple confounders.

Sensitivity analyses were conducted to evaluate the effects of various exclusions on the study results.

Study Results

The study included 67,221 patients diagnosed with AF, reflecting an average CHA2DS2-VASc score of 3.1±1.6. The cohort’s average age was 72.4±12.3 years, with 45% female and 95% white participants. Notably, a significant proportion (26%) were under 65 years old at their initial evaluation.

Within the subgroup of patients younger than 65, males were more predominant, especially in those under 50 (73%) and those between 50 to 65 years old (66.3%). This group exhibited considerable cardiovascular risk factors, including hypertension (55%), diabetes (21%), heart failure (21%), and dyslipidemia (47%).

Lifestyle risk factors such as obesity (over 20% affected) and current smoking (16%) were also notable. Among these younger patients, 4% had a history of stroke, and peripheral vascular disease was present in 1.35%.

Cardiac interventions were frequent: 3% had an implantable cardioverter-defibrillator, 2% had a pacemaker, 5.5% underwent percutaneous coronary intervention, and 2.5% had prior mitral valve surgery.

Additional comorbidities included obstructive sleep apnea (18%), chronic obstructive pulmonary disease (11%), and chronic kidney disease (1.3%).

At baseline, over half of the patients under 65 were taking anticoagulants, with similar rates for aspirin and significant use of class 1 (6%) and class 3 (17%) antiarrhythmic drugs.

Mortality and hospitalization rates varied by age, with the younger cohort experiencing notably lower mortality rates compared to their older counterparts. In the under-50 age group, the 5-year and 10-year mortality rates were 5.6% and 10.3%, respectively, which approximately doubled in the 50 to 65 age group to 11.5% and 20.8%.

Hospitalization rates for AF, heart failure, and myocardial infarction were reported in 31%, 12%, and 2.7% of those under 50, while those figures increased to 38%, 19%, and 4.7% in the 50 to 65 age group.

Further analysis revealed multiple cardiovascular risk factors and comorbidities independently associated with all-cause mortality among those under 65. Heart failure, peripheral vascular disease, diabetes, coronary artery disease, smoking, and obesity significantly impacted mortality rates.

Chronic kidney disease and chronic obstructive pulmonary disease were also associated with poorer outcomes. Interaction analyses indicated a significant correlation between age and the impact of hypertension and heart failure on mortality rates.

Comparison of the AF cohort with national mortality estimates highlighted a considerably higher all-cause mortality rate among AF patients, particularly pronounced in younger males and females. Furthermore, after adjusting for cardiac and non-cardiac risk factors, AF significantly increased the mortality hazard in patients under 65 compared to a control group without AF.

This population also exhibited a heightened risk of hospitalization for myocardial infarction, heart failure, and stroke, underscoring the severe impact of AF in younger patients.

For more information: Mortality, Hospitalization, and Cardiac Interventions in Patients With Atrial Fibrillation Aged <65 Years, Circulation: Arrhythmia and Electrophysiology, https://doi.org/10.1161/CIRCEP.123.012143