Active cannabis use disorder was associated with significantly higher odds of perioperative myocardial infarction in vascular surgery patients, researchers reveal.
Furthermore, people with the disorder were far likelier to have an acute perioperative stroke diagnosis when undergoing carotid endarterectomy, according to Brandon McGuinness, MD, a resident at McMaster University in Hamilton, Canada, who presented the findings during Scientific Session 2 of SVS ONLINE on June 23. “Due to limitations in administrative data, it is unclear if this represents a true effect or selection bias,” he said. “These findings warrant further investigation in a prospective cohort.”
The rationale of McGuinness et al was built around heavy cannabis use’s known adverse impact on cardiovascular and cerebrovascular outcomes—this being the case both in the general population and in patients presenting for surgery, they said. “However, there have been no previous studies that have focused on patients undergoing vascular surgical procedures. The objective of this study was to determine the perioperative risk of cannabis use disorder, primarily cardiovascular risk, in perioperative vascular surgery patients.”
A cohort of more than half a million was derived from the National Inpatient Sample (2006–2015). A retrospective study was devised involving people undergoing one of six elective and emergent vascular surgical procedures: carotid endarterectomy, infrainguinal bypasses, open abdominal aortic aneurysm (AAA) repair, aortobifemoral bypass, endovascular aortic aneurysm repair or peripheral arterial endovascular procedures.
Patients with active cannabis use disorder, as identified by the International Classification of Diseases, 9th edition, were matched in a 1:1 fashion using propensity scores. The primary outcome was perioperative myocardial infarction. Secondary outcomes included cerebrovascular accident, sepsis, deep vein thrombosis, pulmonary embolism, acute kidney injury requiring dialysis, respiratory failure, in-hospital mortality, total cost and length of stay.
Among the 510,007 patients identified, rates of the disorder in the cohort increased from 1.3 to 10.3 per 1,000 admissions (p<0.001) over the 10-year period. After propensity score matching, the cohort consisted of 4,684 patients.
“Those with the disorder demonstrated a statistically significant higher rate of perioperative myocardial infarction (3.3% vs. 2.1%; odds ratio [OR]: 1.56; 95% confidence interval [CI], 1.09–2.24; p=0.0159),” McGuinness told viewers. “We also measured a statistically significant higher rate of perioperative stroke in those with cannabis use disorder (5.5% vs. 3.5% OR: 1.59; 95% CI, 1.20–2.12; p=0.0013).”
Additionally, in a sensitivity analysis—where the risk was evaluated within each type of procedure—this increased risk of perioperative cerebrovascular accident was primarily seen in patients undergoing carotid endarterectomy, he said. Those with the disorder demonstrated lower rates of sepsis (3.3% vs. 5.1%; OR: 0.64; 95% CI, 0.47-0.85; p=0.0024). “In a separate sensitivity analysis, using survey specific logistic regression procedures in the entire unmatched cohort, we obtained similar results, though the findings for sepsis and cerebrovascular accident failed to reach statistical significance when correcting for multiple testing (myocardial infarction: p=0.0011; cerebrovascular accident: p=0.0306; sepsis: p=0.0087),” McGuinness explained.
Other secondary outcomes, including cost and length of stay, did not reach the level of statistical significance.
“As can be seen, the increased odds of stroke in those with cannabis use order are mainly incurred in those undergoing carotid endarterectomy,” McGuinness noted. “The increased rate of myocardial infarction in those with cannabis use disorder is consistent with prior studies both in elective surgical patients and the general population.”
Further studies are warranted to evaluate the management of cannabinoids in heavy users during the perioperative setting, he said.