Arrhythmia may be a harbinger of death in cannabis users

Arrhythmia may increase the risk of death among cannabis users admitted to the hospital,  as shown in a study presented at EHRA 2021.

Patients with cardiac arrhythmias were 4.5 times more likely to die in the hospital than those without arrhythmia in the study comprising 2.4 million cannabis users.

“People should be aware of this devastating outcome and be careful when using cannabis if they have a concomitant heart problem,” said study author Dr Sittinun Thangjui, an internal medicine resident at Bassett Healthcare Network, Cooperstown, New York, US.

Although cannabis or marijuana is the most common psychoactive substance prescribed globally – from osteoarthritis to a host of other conditions, many of which affect older adults –  there remains to be limited knowledge on the safety of its use in people with arrhythmia.

Thangjui and his team sought to compare the length of hospital stay and mortality among hospitalized cannabis users with and without arrhythmia listed in a large US database. Included in the study were 2, 457, 544 adult users of cannabis admitted to the hospital between 2016 and 2018.

Of these patients, 187, 825 (7.6 percent) had arrhythmia. Atrial fibrillation was the most common type, appearing in more than 40 percent of patients, followed by bradycardia and tachycardia.

Compared with patients without arrhythmia, those with arrhythmia were older. The average age in the arrhythmia group was 50.5 years compared with 38.8 years in the non-arrhythmia group (p<0.01). Those with arrhythmias also had more comorbidities.

In adjusted models, cannabis users with arrhythmia had higher odds of in-hospital mortality vs those without (odds ratio [OR], 4.5; 95 percent confidence interval [CI], 4.09–5.00; p<0.01). The length of hospital stay in patients with arrhythmia was 5.7 days vs 5.1 days in those without (p<0.01). This remained the same despite adjustment for confounding factors such as age, sex, race, income, diabetes, heart failure, chronic kidney disease, obesity, and hospital location.

Clinical implications

“Our findings suggest that heart rhythm disorders may be a warning sign for an increased risk of death among people who use cannabis,” warned Thangjui, although confirmatory studies are warranted.

“In the meantime, it seems sensible to screen patients [cannabis users] for arrhythmias when they present to the hospital so that those with a heart rhythm problem can be closely monitored.”

Screening for marijuana use is also encouraged, especially in young patients presenting with cardiovascular disease as suggested in another study. [J Am Coll Cardiol 2020;75:320-332]