Evaluating Cardiotoxicity and Factors Associated with In-Hospital Mortality Among Emergency Department Patients with Substance Use Disorder: An 11-year retrospective study.

Abstract

Objective: Substance use disorder (SUD)-related emergencies are increasing globally, with cardiotoxicity contributing substantially to morbidity and mortality. This study evaluated cardiotoxicity patterns and factors associated with in-hospital mortality among adults with SUD presenting to the emergency department (ED).

Methods: This retrospective observational study was conducted from January 2014 to December 2024 at Sultan Qaboos University Hospital, University Medical City, Muscat, Oman. Adults aged ≥18 years with SUD and positive urine drug screening (UDS) were included if they had elevated troponin (>14 ng/L), electrocardiographic abnormalities or echocardiographic structural dysfunction. Clinical, laboratory, imaging, management and outcome data were analysed.

Results: A total of 4,400 ED medical records were reviewed; 478 patients had SUD and 78 (16.3%) met the inclusion criteria (mean age = 40.8 ± 12.3 years, 92.3% male). Opiate-class positivity on UDS was the most frequent finding (62.8%), followed by methamphetamine (29.5%). Sinus tachycardia (41.0%) and ST-T changes (15.4%) were the most common electrocardiographic abnormalities. Elevated troponin was present in 87.2%. Overall, in-hospital mortality was 15.4%. Hypokinesia (odds ratio [OR] = 5.12, 95% confidence interval [CI]: 1.08-24.22; P = 0.040) and left ventricular impairment (OR = 6.14, 95% CI: 0.95-39.88; P = 0.057) showed the strongest mortality associations.

Conclusion: Among ED patients with SUD, positive UDS and cardiotoxicity, structural cardiac dysfunction was associated with higher in-hospital mortality. These findings support early cardiovascular assessment, including electrocardiography, troponin testing and selective echocardiography, in high-risk patients with substance-related toxicity.