Cannabis Users With Heart Rhythm Problems Face Increased Mortality Risk, Study Warns
A study of over 2.4 million patient records has found that hospitalized cannabis users with a heart arrhythmia were 4.5 times more likely to die in hospital than those without heart rhythm problems.
The research was presented this week at EHRA 2021, an online scientific congress of the European Society of Cardiology (ESC). The scientists behind the work hope that the findings will serve as a call for heightened awareness around cannabis use and the increased risk of mortality among patients with certain cardiovascular conditions.
Cannabis users with arrhythmia face longer hospital stays, greater mortality risks
Despite an ever-growing number of states and countries legalizing cannabis for medical and/or recreational use, very little is known about the effect of the drug in patients with pre-existing heart problems.
In their new work, researchers from the Bassett Healthcare, New York, and St. Luke’s University Hospital, Pennsylvania, looked to examine the burden of heart arrhythmias in drug users admitted to hospital.
Using data from the National Inpatient Sample (NIS) database, the researchers identified 2,457,544 adults admitted to hospital between January 2016 and December 2018 who had a previous diagnosis of a cannabis use related disorder. Of these patients, 7.6 percent were recorded to have had some form of heart arrhythmia. The most common arrhythmia seen was atrial fibrillation, a condition characterized by an abnormally fast and irregular heartbeat. This was followed by reports of either an abnormally slow or abnormally fast heartbeat.
From analysis of the patient demographic information available, the researchers found that those with an arrhythmia were more likely to be older, with an average age of 50.5 years versus 38.3 years in those without arrhythmia. Those with arrhythmia were also more likely to have comorbid health conditions.
The researchers also carried out an analysis adjusted for a range of potentially confounding demographic and health factors, including age, sex, race, income, hospital location, and the comorbidity of other conditions such as diabetes, heart failure, chronic kidney disease, and obesity. They found that those with an arrhythmia had 4.5 times higher odds of in-hospital mortality than those without heart rhythm problems. The patients with an arrhythmia also had a longer hospital stay on average than those without, by a margin of roughly half a day.
“Our study highlights that heart rhythm disorders may be a warning sign for an increased risk of death in people who use cannabis,” study author Dr Sittinun Thangjui of Bassett Healthcare Network, New York, said in a statement. “More studies are needed to confirm our results. In the meantime, it seems sensible to screen these patients for arrhythmias if they present to hospital so that those with a heart rhythm problem can be closely monitored.”
“People should be aware of this devastating outcome and be careful when using cannabis if they have a concomitant heart problem,” Thangjui added.
Cannabis and heart health
There is not yet a large enough critical mass of studies to conclusively determine whether cannabis is harmful to heart health, but the prevailing attitude among cardiovascular specialists is one of caution.
In a scientific statement released last year, the American Heart Association warned that cannabis did not appear to confer any specific benefits to heart health. The statement also highlighted several studies where cannabis use had been linked to an increased risk of heart attack, atrial fibrillation, and even heart failure.
Another recent study of hospital admissions data revealed a concerning trend where two-thirds of cannabis-using heart attack survivors went on to have a subsequent heart attack, compared to only 41 percent of non-users. A second study, looking at patients who underwent non-surgical interventions to open blocked arteries, found that those who reported using cannabis were more likely to experience complications such as stroke or bleeding following the procedure.
In a study looking specifically at healthy young people, researchers found no differences in resting heart rate or blood pressure levels between cannabis using and non-using groups. However, the cannabis users were observed to have fewer apical rotations and greater aortic stiffness, factors associated with cardiovascular disease.
“We do acknowledge the limited scope of evidence defining the cardiovascular safety of marijuana at present,” Muthiah Vaduganathan, a cardiologist at Brigham and Women's Hospital, Massachusetts, told Analytical Cannabis last year. “However, based on what we know, we believe there is sufficient evidence to give us pause.”
In a review article published in the Journal of the American College of Cardiology, Vaduganathan and his colleagues estimated there to be upwards of two million American cannabis users living with some form of cardiovascular disease. Given that only around half of the respondents to the national survey answered all relevant survey questions, the researchers suggested that the real figure could be significantly larger.
“We believe broader-scale clinical research is needed to better understand the safety of marijuana, especially on cardiovascular health,” Vaduganathan added.