Heart attack patients with a past history of marijuana use possess greater in-hospital survival rates, according to a new study published in the journal PLOS One, and first reported on by NORML.
For the study researchers at the University of Colorado School of Medicine, Division of Cardiology compared the hospital records of over 3,800 heart-attack patients who acknowledged having consumed cannabis or had tested positive for it to those of over 1.2 million similarly matched controls.
Consistent with prior data, “[M]arijuana use prior to AMI (acute myocardial infarctions) was associated with decreased in-hospital mortality post AMI.” In addition, “Average length of stay for marijuana users was shorter than non-marijuana users (4.51 days vs. 6.25 days, respectively).”
Cannabis-using subjects, on average, were 10 years younger than non-users. However, authors reported that “age-specific analysis and controlling for other potential confounders did not explain these findings.” Patients with past cannabis exposure also were less likely to suffer from hypertension, heart failure, coronary artery disease, diabetes, and atrial fibrillation.
Researchers concluded: “In this large, multiregional analysis, marijuana use reported during hospitalization for AMI was associated with a significantly decreased risk of in-hospital mortality. … Given the increasing prevalence and acceptance of marijuana use, these findings suggest that additional study is warranted to further investigate these discoveries and to identify potential mechanisms by which marijuana is associated with improved short-term outcomes following AMI and for mitigating the possible negative effects of concomitant substance use.”
The findings are consistent with prior studies reporting that a history of past cannabis use is associated with reduced in-hospital mortality among patients admitted for traumatic brain injuries, burn victims, those undergoing certain orthopedic surgeries, and those hospitalized with other forms of severe trauma.
The full text of the study, titled “Marijuana use and short-term outcomes in patients hospitalized for acute myocardial infarction,” appears in the journal PLOS One. The full abstract of the study can be found below:
Marijuana use is increasing worldwide, and it is ever more likely that patients presenting with acute myocardial infarctions (AMI) will be marijuana users. However, little is known about the impact of marijuana use on short-term outcomes following AMI. Accordingly, we compared in-hospital outcomes of AMI patients with reported marijuana use to those with no reported marijuana use. We hypothesized that marijuana use would be associated with increased risk of adverse outcomes in AMI patients. Hospital records from 8 states between 1994–2013 were screened for patients with a diagnosis of AMI. Clinical profiles and outcomes in patients with reported use of marijuana were compared to patients without reported marijuana use. Short-term outcomes were defined as adverse events that occurred during hospitalization for an admitting diagnosis of AMI. The composite primary outcome included death, intraaortic balloon pump placement, (IABP), mechanical ventilation, cardiac arrest, and shock. In total, 3,854 of 1,273,897 AMI patients reported use of marijuana. The marijuana cohort was younger than (47.2 vs. 57.2, respectively) and had less coronary artery disease than the non-marijuana cohort. In multivariable analysis including age, race and common cardiac risk factors, there was no association between marijuana use and the primary outcome (p = 0.53), but marijuana users were more likely to be placed on mechanical ventilation (OR (odds ratio) 1.19, p = 0.004). Interestingly, marijuana-using patients were significantly less likely to die (OR 0.79, p = 0.016), experience shock (OR 0.74, p = 0.001), or require an IABP (OR 0.80, p = 0.03) post AMI than patients with no reported marijuana use. These results suggest that, contrary to our hypothesis, marijuana use was not associated with increased risk of adverse short-term outcomes following AMI. Furthermore, marijuana use was associated with decreased in-hospital mortality post-AMI.