Risk Factors and Emergency Department Outcomes in Methamphetamine-Associated Cardiomyopathy: A Case-Control Study

Methamphetamine-associated cardiomyopathy (MACM) is a known complication of methamphetamine use; however, risk factors and outcomes of patients with MACM are not well understood.

This study aims to identify risk factors, emergency department (ED) interventions, and outcomes for MACM.

This case-control study was conducted between 2012 and 2020 at two academic EDs. ED patients ≥18 years with an index visit that included documented methamphetamine use were included. Patients with documented MACM during follow-up (3 months-3 years) were considered cases (MACM). A control group comprised of patients with documented methamphetamine use but no known MACM was matched at a 2:1 ratio. Logistic regression was used to model risk factors for MACM.

A total of 9833 patients with methamphetamine use were identified. From this, 160 MACM patients were matched to 322 controls. The mean age was 48.4 years, and 143 patients (29.7%) were female. MACM patients were more likely to be admitted on their index visit (45.6% vs. 34.8%, p = 0.021). Significant variables associated with MACM included: admission at the index visit (odds ratio [OR] 1.51), diabetes (OR 3.02), kidney disease (OR 5.47), and pulmonary disease (OR 2.39). MACM patients had more ED visits in the follow-up period (10.1 vs. 7, p = 0.009) and were admitted at a higher rate across all visits (32.5% vs. 15.4%, p = 0.009). Additionally, MACM patients had significantly longer hospital stays than controls (mean 18 additional days, p = 0.009).

Patients who developed MACM had traditional risk factors for heart failure and experienced significantly more ED visits, more hospitalizations, and longer hospital stays than matched controls.