Systematic review finds cannabis smoking linked to heart attacks and cardiovascular disease

A systematic review of 85 publications involving over 541,000 subjects found that the large majority of Level I-III studies highlighted increased cardiovascular risk from cannabis use, including acute coronary syndrome.

Richards, John R et al.·Clinical toxicology (Philadelphia·2019·Moderate EvidenceSystematic Review
RTHC-02256Systematic ReviewModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Systematic Review
Evidence
Moderate Evidence
Sample
N=541,518

What This Study Found

Five Level I systematic reviews, 14 Level II studies (83,961 subjects), and 14 Level III studies (457,495 subjects) were identified. All but five of these highlighted increased cardiovascular risk. In 51 case reports (62 subjects, average age 31), 60% showed ST-elevation, 35% had left anterior descending artery involvement, 34% had cardiomyopathy, and 23% died.

Key Numbers

85 publications, 541,518 subjects. 5 Level I reviews, 14 Level II studies (83,961 subjects), 14 Level III studies (457,495 subjects). Case reports: avg age 31, 60% ST-elevation, 23% died. Only 10% female.

How They Did This

Systematic review of PubMed, Google Scholar, and OpenGrey following PRISMA guidelines. Focused on smoked phytogenic cannabis and acute coronary syndrome. 85 publications covering 541,518 subjects were included.

Why This Research Matters

Cannabis is widely perceived as cardiovascularly benign, but this extensive review shows a consistent signal of increased heart attack risk, particularly in young adults who would not typically be at risk.

The Bigger Picture

Heart attacks in young adults who smoke cannabis may be missed or misattributed. The mechanism likely involves sympathetic activation, vascular inflammation, and platelet activation from cannabis smoke.

What This Study Doesn't Tell Us

No Level I randomized controlled trials specifically address this association. Case reports are inherently biased toward severe outcomes. Most evidence involves smoked cannabis; other forms were excluded.

Questions This Raises

  • ?Does vaporized or edible cannabis carry the same cardiovascular risk?
  • ?Is the risk dose-dependent?
  • ?Would switching from smoked to non-combustion methods reduce cardiac events?

Trust & Context

Key Stat:
23% of case report patients died from cannabis-associated acute coronary syndrome
Evidence Grade:
Moderate: large systematic review with extensive literature coverage, though limited by absence of randomized trials.
Study Age:
Published in 2019.
Original Title:
Cannabis use and acute coronary syndrome.
Published In:
Clinical toxicology (Philadelphia, Pa.), 57(10), 831-841 (2019)
Database ID:
RTHC-02256

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Analyzes all available research on a topic using a structured method.

What do these levels mean? →

Frequently Asked Questions

Can cannabis cause a heart attack?

This review found a consistent association between cannabis smoking and acute coronary syndrome across multiple study types. The risk appears highest shortly after use and in younger individuals.

Is edible cannabis safer for the heart?

This review specifically excluded non-smoked cannabis, so it cannot answer that question. The combustion-related mechanisms (carboxyhemoglobin, smoke-induced inflammation) would not apply to edibles, but other risks (heart rate elevation) might still be relevant.

Read More on RethinkTHC

Cite This Study

RTHC-02256·https://rethinkthc.com/research/RTHC-02256

APA

Richards, John R; Bing, Mary L; Moulin, Aimee K; Elder, Joshua W; Rominski, Robert T; Summers, Phillip J; Laurin, Erik G. (2019). Cannabis use and acute coronary syndrome.. Clinical toxicology (Philadelphia, Pa.), 57(10), 831-841. https://doi.org/10.1080/15563650.2019.1601735

MLA

Richards, John R, et al. "Cannabis use and acute coronary syndrome.." Clinical toxicology (Philadelphia, 2019. https://doi.org/10.1080/15563650.2019.1601735

RethinkTHC

RethinkTHC Research Database. "Cannabis use and acute coronary syndrome." RTHC-02256. Retrieved from https://rethinkthc.com/research/richards-2019-cannabis-use-and-acute

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.