PHOENIX, ARIZ. – Cardiovascular deaths and death rates related to atrial fibrillation have risen since 1999, with significant acceleration following 2009, results from a cross-sectional analysis of national data show.
Doug Brunk/MDedge News
Dr. Yoshihiro Tanaka
“AFib is the most common arrhythmia disorder in the United States and it is estimated that it will effect more than 12 million Americans by 2030,” Yoshihiro Tanaka, MD, PhD, said at the Epidemiology and Prevention/Lifestyle and Cardiometabolic Health meeting. “The predicted lifetime risk ranges from 25% to 35%, and AFib is associated with an increased risk for heart failure, stroke, and death.”
A recent review reported that declines in total heart disease mortality rates in the United States have plateaued since 2011 (JAMA 2019;322[8]:780-2). However, it is not well understood what factors such as AFib contribute to this rate of plateau. In an effort to quantify U.S. trends in AFib-related CVD death rates, Dr. Tanaka and colleagues conducted a serial cross-sectional analysis of death certificate data from the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (WONDER) database during 1999-2017.
Outcomes included age-adjusted mortality per 100,000 based on the 2000 U.S. standard population. The researchers also used joinpoint regression to calculate the average annual percentage change over time and conducted subgroup analyses by race and sex and across two age groups: 35-64 years and 65-84 years.
In all, 522,104 AFib-related CVD deaths were identified during 1999-2017. Dr. Tanaka reported that age-adjusted mortality increased from 16.0 per 100,000 persons in 1999 to 22.2 per 100,000 person in 2017, with an acceleration following an inflection point in 2009. Specifically, the average annual percentage change in AFib-related CVD deaths rose from 0.4% in 2009 to 3.5% in 2017 (P < .001). “These increases were consistent across all race-sex subgroups,” said Dr. Tanaka, of the department of preventive medicine at Northwestern University, Chicago. “Relative increases were also greater in younger compared with older adults, although the absolute number of deaths in younger adults was less.”
The researchers observed that age-adjusted mortality increased across blacks and whites in both age groups, with a more pronounced increase among black and white men. Black men had the highest age-adjusted mortality among persons aged 35-64 (6.5 per 100,000 persons, compared with 4.2 among white men, 2.8 in black women, and 1.6 in white women 1.6 per 100,000). At the same time, white men had the highest age-adjusted mortality rate among those aged 65-84 years (112.5 per 100,000 persons, compared with 87.7 in black men, 77.4 in white women, and 61.3 in black women).
In an interview, one of the session’s moderators, Alvaro Alonso, MD, PhD, said that the study’s reliance on mortality data is a limitation. “You have to be careful with that, because it’s not the whole picture,” said Dr. Alonso, professor of epidemiology at the Rollins School of Public Health at Emory University, Atlanta. “It could be an underestimation of what is going on. The increase in recent years is probably due to a higher awareness of AFib as a risk factor for stroke; it’s more on the radar. Also, around 2009-2010, we started having new anticoagulants for AFib. It’s getting diagnosed more. When you look at coronary heart disease and stroke, there has been a decrease over time. In mortality and incidence of AFib, we don’t have that. That’s probably because we don’t know very much about what the risk factors for AFib are and how to prevent it.”
Dr. Tanaka said that the cause of increase in AFib-related CVD mortality can be classified into two major categories: a balance between case fatality of AFib and the prevalence of AFib. “The case fatality rate should have decreased over the last years,” he said at the meeting, which was sponsored by the American Heart Association. “In contrast, in the context of the aging of the population, the prevalence of AFib increased over the past years. Contributing factors include increasing awareness of AFib, a change in coding between ICD-9 and ICD-10, and a change in coding practices by physicians.”
Strengths of the study, he said, include its large sample size and the fact that the researchers were able to capture data from all death certificates filed in the United States. Limitations include the fact that the data “do not identify if changes in age-adjusted mortality rates are due to changing incidence or to case fatality rates,” he said. “CDC WONDER does not allow us to explore causes of these descriptive findings, but this would be an important next step.”
Dr. Tanaka reported having no financial disclosures.
SOURCE: Tanaka Y. EPI/Lifestyle 2020, Session 5, Abstract 15.