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.

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.