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

Abstract

BackgroundMethamphetamine-associated cardiomyopathy (MACM) is a known complication of methamphetamine use; however, risk factors and outcomes of patients with MACM are not well understood. Study ObjectivesThis study aims to identify risk factors, emergency department (ED) interventions, and outcomes for MACM. MethodsThis 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. ResultsA 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). ConclusionPatients 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.