Clinical and electrocardiographic factors associated with adverse cardiovascular events in bupropion exposures.

Bupropion toxicity can cause cardiogenic shock, ventricular dysrhythmias, and death. Clinical and electrocardiographic factors associated with adverse cardiovascular events in bupropion toxicity have not been well-studied. This study aimed to identify factors associated with adverse cardiovascular events in adult patients with isolated bupropion exposures. This retrospective cohort study queried the National Poison Data System from 2019 through 2020. We included patients 20 years or older with acute or acute-on-chronic single-agent bupropion exposures evaluated in a healthcare facility. Exclusion criteria were confirmed non-exposure, withdrawal as a reason for exposure, lack of follow-up, documentation that exposure was probably not responsible for the effects, and missing data. The primary outcome was adverse cardiovascular events, defined as the presence of any of the following: vasopressor use, ventricular dysrhythmia, myocardial injury, or cardiac arrest. Independent variables were age, the intentionality of exposure, seizures, tachycardia, QRS widening, and QTc prolongation. Multivariable logistic regression was performed to test for independent associations between independent variables and adverse cardiovascular events. Of 4,640 patients included in the final analysis (56.7% female, 56.5% suspected suicidal intent), 68 (1.47%) experienced an adverse cardiovascular event. Age (odds ratio 1.03; 95% confidence intervals 1.02-1.05), single seizure (odds ratio 9.18; 95% confidence intervals 4.24-19.9) and complicated seizures (odds ratio 38.9; 95% confidence intervals 19.3-78.1), QRS widening (odds ratio 3.01; 95% confidence intervals 1.62-5.59), and QTc prolongation (odds ratio 1.76; 95% confidence intervals 1.00-3.10) were independently associated with adverse cardiovascular events. No patients with unintentional exposure experienced adverse cardiovascular events, prohibiting intentionality from inclusion in the regression model. In the post hoc subgroup analysis of intentional exposures, age, single and complicated seizures, and QRS widening remained independently associated with adverse cardiovascular events. Increasing age, seizures, QRS widening, and QTc prolongation were associated with adverse cardiovascular events in bupropion exposures. Adverse cardiovascular events did not occur in unintentional exposures. Further research is needed to develop screening tools and treatments for bupropion cardiotoxicity.