Cannabis use linked to worse long-term outcomes after early ACS

BACKGROUND: Cannabis consumption has increased among young adults, but its long-term cardiovascular impact remains unclear. This study assessed the association between cannabis use at admission for acute coronary syndrome (ACS) and long-term prognosis. METHODS: A retrospective, single-centre cohort included patients under the age of 45 years admitted for ACS between 1 January 2010 and 1 March 2025, all of whom reported current tobacco use at admission. Based on urinary testing at admission, patients were classified as cannabis users or non-users. The primary endpoint was major adverse cardiovascular events (MACE), a composite of death, stroke, recurrent myocardial infarction, arrhythmia or heart failure-related events. A propensity-weighted analysis adjusted for socioeconomic and cardiovascular risk factors was conducted. Weighted survival curves were plotted, and a Cox model truncated at 6 years was used to estimate the HR for MACE associated with cannabis use. RESULTS: Among 188 included patients, 77 (41.0%) were cannabis users and 111 (59.0%) non-users. The median follow-up was 2.93 (0.45-5.53) years. Weighted Kaplan-Meier curves differed significantly (Fleming-Harrington p=0.002), with a higher cumulative incidence of MACE among cannabis users. In the inverse probability of treatment weighting Cox model, cannabis use was associated with a higher hazard of MACE (HR 2.52, 95%&#x2009;CI 1.05 to 6.02; p=0.04). Cannabis users also had higher peak troponin levels, higher leucocyte counts and a greater use of postprocedural anticoagulation (all p<0.05). CONCLUSIONS: Cannabis use in young adults with ACS was associated with a 2.5-fold higher hazard of MACE over 6 years, highlighting the need to take cannabis use into account in cardiovascular care pathways.