A new longitudinal study of more than 23 million people in the US concludes that some commonly used and abused drugs pose previously unidentified risks for the development of atrial fibrillation (AF). The results appeared in the European Heart Journal.
The researchers analysed data from diagnostic codes from every hospital admission, emergency room visit and medical procedure in California for the years 2005 through 2015, identifying nearly one million people without preexisting AF, but who later developed AF during these years.
They found 132 834 patients used cannabis, 98 271 used methamphetamine, 48 700 used cocaine, and 10 032 used opiates. In the study, the researchers found that marijuana users had a 35% increased likelihood of later developing AF.
“Despite exhibiting a weaker association with incident AF than the other substances, cannabis use still exhibited an association of similar or greater magnitude to risk factors like dyslipidaemia, diabetes mellitus, and chronic kidney disease. Furthermore, those with cannabis use exhibited similar relative risk of incident AF as those with traditional tobacco use,” the study authors reported.
“To my knowledge, this is the first study to look at marijuana use as a predictor of future atrial fibrillation risk,” said principal investigator Gregory Marcus, MD, MAS, a UCSF professor of Medicine with the Division of Cardiology.
AF is an abnormally disordered pumping rhythm arising from electrical disturbances in the atria. In severe cases of faulty atrial pumping, clots may form in the atria, and then break off into the bloodstream and cause deadly strokes. AF-related strokes cause more than 150 000 US deaths each year.
Unlike cocaine or methamphetamine use, both stimulants previously known to sometimes lead to sudden cardiac death due to profound disruptions in the orderly electrical signalling and pumping within ventricles there is no demonstrated mechanism whereby marijuana use causes heart arrhythmias.
