Minimum National Prevalence of Diagnosed Atrial Fibrillation Inferred From California Acute Care Facilities.

BACKGROUND: Prevalence estimates of atrial fibrillation (AF) from large populations have not been updated for >2 decades. Using data from 1996 to 1997, a previous study projected that there would be 3.3 million adults with AF in the United States in 2020. OBJECTIVES: The purpose of this study was to determine the contemporary age-, sex-, and race-standardized prevalence and the number of adults with diagnosed AF in the United States. METHODS: We merged California's state-wide health care databases to assemble a cohort of adults aged ≥20 years who received hospital-based care in California from 2005 to 2019. International Classification of Diseases codes were used to identify AF and other comorbidities. After accounting for deaths, we utilized the U.S. Census to calculate the national age-, sex-, and race-standardized estimates of diagnosed AF. RESULTS: Of 29,250,310 patients (mean age 50.6 ± 19.8 years, 53.8% women, 50.1% White), 2,003,867 (6.8%) had an AF diagnosis. The proportion of patients with diagnosed AF increased from 4.49% in 2005 to 2009 to 6.82% in 2015 to 2019. Over time, AF patients became relatively younger, were less likely to be female or White, and were more likely to have hypertension and diabetes. Standardizing based on age-, sex-, race-, and ethnicity-based proportions to the U.S. population, we estimate that the current national prevalence of diagnosed AF is at least 10.55 million (95% CI: 10.48-10.62 million), comprising 4.48% (95% CI: 4.47%-4.49%) of the adult population. CONCLUSIONS: The prevalence of diagnosed AF in the United States is higher than previously estimated. More efficient prevention and treatment strategies are needed to curb the burden of AF in the United States.

Smoking Cessation and Incident Atrial Fibrillation in a Longitudinal Cohort.

BACKGROUND: Although smoking heightens the risk of AF, it remains unknown if that risk is amenable to modification after smoking cessation. OBJECTIVES: This study sought to evaluate the association between smoking cessation and atrial fibrillation (AF) risk in a large longitudinal cohort. METHODS: After excluding those with prevalent AF and no history of smoking at baseline, we evaluated 146,772 UK Biobank participants with serial smoking assessments. We compared AF risk between former smokers at baseline and those who quit smoking during the study to current smokers. Incident AF was ascertained from outpatient and inpatient encounters and identified using International Classification of Diseases codes. Cox models were used to compare the risk of incident AF among current and former smokers as well as those who quit smoking during the study while controlling for age, sex, race, body mass index, education, cardiovascular comorbidities, alcohol use, and pack-years. RESULTS: Among the 146,772 participants (48.3% female; age: 57.3 ± 7.9 years), 37,377 (25.5%) currently smoked; 105,429 (72.0%) were former smokers; and 3,966 (2.7%) quit smoking during the study. Over a mean 12.7 ± 2.0 years of follow-up, 11,214 (7.6%) participants developed AF. Compared to current smokers, the adjusted risk of AF was 13% lower in former smokers (HR: 0.87; 95% CI: 0.83-0.91) and 18% lower in those who quit smoking during the study (HR: 0.82; 95% CI: 0.70-0.95). CONCLUSIONS: Compared to those who continue to smoke, smoking cessation was associated with a lower risk of AF.

Systemic infarcts among patients with atrial fibrillation.

BACKGROUND: The epidemiology of atrial fibrillation (AF)-associated thromboembolic complications outside of ischemic strokes has not been thoroughly elucidated. OBJECTIVE: The aim of this study was to describe the epidemiology of AF-associated systemic infarcts and relevant interactions by sex and race/ethnicity. METHODS: Using the Office of Statewide Health Planning and Development, we performed a longitudinal analysis of patients aged ≥18 years who received ambulatory surgery, emergency, or inpatient medical care in California between 2005 and 2015. We determined the distribution of infarct locations and risks of systemic infarcts for patients with AF. Interaction analyses by sex and race/ethnicity were conducted. RESULTS: Of 1,321,694 patients with AF, the average annual rate of systemic infarct was 2.1% ± 0.18% compared with 0.56% ± 0.06% in the 22,944,488 patients without AF. The increased frequency of these infarcts was observed for every body area investigated. After adjustment for potential confounders and mediators, patients with AF experienced a 45% increased risk of a systemic infarct (hazard ratio, 1.45; 95% confidence interval, 1.44-1.47; P < .001). Women, Asians, Blacks, and Hispanics each exhibited a statistically significant heightened relative risk of systemic infarcts in the presence of AF. CONCLUSION: AF increases the risk of infarcts throughout the body. Susceptibility to these systemic infarcts varies by sex and race/ethnicity in patterns similar to differential risks for stroke. The presence of a systemic infarct in the absence of a clear cause should raise suspicion for AF, and the potential benefits of AF prevention and anticoagulation should be considered beyond only infarcts to the brain.

Cannabis use and incident atrial fibrillation in a longitudinal cohort.

BACKGROUND: Cannabis use is increasing worldwide. While prior studies have reported an association between cannabis use and a higher risk of atrial fibrillation (AF), most were cross-sectional and generally relied on diagnostic coding to identify cannabis users, which may not be representative of the typical recreational cannabis user. OBJECTIVE: The purpose of this study was to examine the association between recreational cannabis use and lifetime AF risk. METHODS: We evaluated the AF risk of participants of the UK Biobank cohort who completed the cannabis use lifestyle questionnaire. Cannabis exposure was categorized as "Occasional Use" for less than 100 times used, "Frequent Use" for more than 100 times used, and "Never" users. AF events were identified using International Classification of Diseases codes. Cox models were used to estimate the hazard ratios (HRs) between cannabis use and incident AF and were subsequently adjusted for age, sex, race, alcohol, coffee, smoking, education, and baseline cardiovascular comorbidities. RESULTS: A total of 150,554 participants (mean age 63.4 ± 7.7 years; 86,487 (57.4%) female; and 33,442 (22.2%) using cannabis at least once) were followed for a mean period of 6.1 ± 0.6 years. After multivariable adjustment, there were no statistically significant differences in incident AF among occasional users (HR 0.98; 95% confidence interval 0.89-1.08) nor frequent users (HR 1.03; 95% confidence interval 0.81-1.32) as compared with never users. CONCLUSION: In a large prospective cohort study, there was no evidence that cannabis use was associated with a higher risk of incident AF. An evaluation of cannabis ingestion methods and quantification was not possible using the current data set.