J Am Coll Cardiol. 2026 Jul 30:S0735-1097(26)07131-7. doi: 10.1016/j.jacc.2026.07.014. Online ahead of print.
ABSTRACT
BACKGROUND: Inhaled cannabis is widely legal in the United States. Data regarding cardiovascular effects are conflicting and generally arise from observational studies.
OBJECTIVES: The goal was to evaluate the acute effects of cannabis inhalation on cardiac ectopy.
METHODS: We conducted a prospective, randomized, crossover trial to assess effects of inhaled cannabis on cardiac ectopy, mean glucose levels, step counts, and sleep durations. Adults who smoked or vaped cannabis on a regular basis without a history of cardiac arrhythmias were enrolled. Participants were randomly assigned each day to inhale vs abstain from cannabis via text messages for 14 days. Adherence was assessed using time-stamped Zio patch button presses at the time of cannabis use, daily surveys, and, in a subset, salivary mass spectrometry. The primary outcome was daily cardiac ectopy (daily premature atrial contractions and premature ventricular contractions).
RESULTS: Of 108 participants (mean age 32 ± 10 years, 59% women, and 37% non-Hispanic White) experiencing a total of 713 days randomized to inhaled cannabis and 616 days randomized to abstinence, randomization adherence was imperfect but generally supportive of assignment adherence. Inhaled cannabis resulted in a statistically significant 9% reduction in ectopic beats (rate ratio [RR]: 0.91; 95% CI: 0.85-0.98; P = 0.02). Daily premature atrial contractions decreased by 10% (RR: 0.90; 95% CI: 0.82-0.97; P = 0.012), whereas premature ventricular contractions showed no significant change. Each cannabis inhalation was associated with a 2% reduction in ectopic beats (RR: 0.98; 95% CI: 0.97-0.99; P = 0.043). No significant differences were observed for step counts, sleep duration, or glucose levels.
CONCLUSIONS: In a pragmatic crossover design including habitual cannabis users, randomization to inhaled cannabis was associated with less cardiac ectopy, driven by fewer premature atrial contractions. Potential withdrawal effects, moderate adherence, and co-intervention limit interpretation of causal mechanism. (Marijuana and Acute Risk of Arrhythmia-Joint Abstinence and Exposure [MARY-JANE]; NCT06021613).
PMID:42584385 | DOI:10.1016/j.jacc.2026.07.014
