By Randomized Trial Results Published
A new randomized crossover trial has linked cannabis inhalation to a reduction in cardiac ectopy among regular users. The study was published in the Journal of American College of Cardiology. Researchers assigned participants to inhale or abstain from cannabis daily for 14 days.
The trial included 108 adults who smoked or vaped cannabis regularly. The mean age of participants was 32 years, and 59 percent were women. Participants did not have a history of cardiac arrhythmias before the study began.
Researchers used time-stamped Zio patch button presses to determine adherence. They also relied on daily surveys and salivary mass spectrometry for verification. The primary outcome measure was daily cardiac ectopy, defined as premature atrial and ventricular contractions.
Key Findings on Heart Rhythm
Inhaled cannabis led to a 9% reduction in ectopic beats, according to the data. This corresponded to an adjusted difference of 15 fewer ectopic beats per day.
The rate of daily premature atrial contractions also fell significantly. Premature ventricular contractions did not show a significant change during the trial period.
Each individual cannabis inhalation yielded a 2% reduction in ectopic beats. These findings suggest a consistent relationship between random assignment and heart rate variability.
Expert Caution and Limitations
Gregory Marcus, MD, MAS, is the study investigator and an endowed professor at the University of California, San Francisco. He noted that the relationships between random assignment on heart rate variability were significant and consistent. He stated that this likely provides good evidence for the field.
Quinn R. Pack, MD, MSc, is an associate professor at UMass Chan Medical School. He said he strongly discourages any clinician from thinking that this study creates a reliable evidence base for a therapeutic effect.
He noted that effect sizes were small and seem unlikely to be clinically significant.
The investigators highlighted several limitations, including heterogeneous cannabis products and possible withdrawal effects. The population was relatively young with generally low frequencies of ectopy. Step counts, sleep duration, and glucose levels did not significantly differ between the groups.
