Cannabis use independently associated with higher heart attack risk in French nationwide study | Research

The takeaway

In a French nationwide analysis of over 3.3 million hospitalized patients, cannabis use was the only illicit drug independently associated with a higher risk of acute myocardial infarction, though prognosis after a heart attack was similar regardless of drug use.

Cardiologists, cannabis users concerned about heart health, and public health researchers studying cardiovascular risks of substance use.

32% higher risk of heart attack associated with cannabis use (HR 1.32)

What the researchers found

Among all illicit drugs evaluated, only cannabis use was significantly associated with higher AMI risk (HR 1.32, 95% CI 1.09-1.59). However, after propensity-score matching 738,899 AMI patients, those with illicit drug use history had similar rates of death, cardiovascular death, stroke, and heart failure compared to non-users.

Why it matters

This is one of the largest studies to examine cannabis and heart attack risk at a population level. The finding that cannabis independently predicted AMI but not worse outcomes after AMI adds nuance to the cardiovascular risk discussion.

The numbers in context

3,381,472 hospitalized patients in phase 1; 738,899 AMI patients in phase 2; cannabis HR 1.32 for AMI; cocaine OR 2.44, amphetamine OR 2.74, cannabis OR 2.65 for premature ASCVD; no difference in post-AMI mortality

How the study worked

Researchers used the entire French hospital-discharge database. Phase 1 analyzed 3,381,472 patients hospitalized in 2013 with 5-year follow-up to identify AMI predictors. Phase 2 analyzed 738,899 AMI patients from 2010-2018, matching 3,827 illicit drug users to non-users by propensity score.

What this study cannot tell us

Administrative database may undercount illicit drug use. Cannot distinguish frequency or method of cannabis use. Observational design cannot prove causation. French population may not generalize globally.

How to read the evidence

Massive nationwide longitudinal cohort using complete hospital discharge data with propensity-score matching, though administrative data limitations apply.

When this study was published

Published in 2021 using data from 2010-2018.

The bigger picture

The dissociation between increased AMI incidence but similar post-AMI prognosis suggests cannabis may trigger acute cardiac events rather than worsen underlying cardiac disease, though more research is needed to confirm this interpretation.

Questions still open

What mechanism links cannabis to AMI risk? Does the route of administration matter? Would the same pattern hold in populations with different baseline cardiovascular risk profiles?

Common questions

Did cannabis users have worse outcomes after a heart attack?

No. After propensity-score matching, there was no significant difference in death, cardiovascular death, stroke, or heart failure between illicit drug users and non-users following a heart attack.

How did cannabis compare to other drugs?

Cannabis was the only illicit drug independently associated with higher AMI incidence. Other drugs like cocaine and amphetamines were associated with premature cardiovascular disease but not specifically with AMI after adjusting for other factors.

Read the original research

Outcomes in patients with acute myocardial infarction and history of illicit drug use: a French nationwide analysis.

European heart journal. Acute cardiovascular care, 10(9), 1027-1037

View on PubMed ↗Publisher’s paper ↗

Citation

Ma, Iris; Genet, Thibaud; Clementy, Nicolas; Bisson, Arnaud; Herbert, Julien; Semaan, Carl; Bouteau, Jérémie; Angoulvant, Denis; Ivanes, Fabrice; Fauchier, Laurent. (2021). Outcomes in patients with acute myocardial infarction and history of illicit drug use: a French nationwide analysis.. European heart journal. Acute cardiovascular care, 10(9), 1027-1037. https://doi.org/10.1093/ehjacc/zuab073