Clinical Differences between Methamphetamine and Non-Methamphetamine Associated Non-Ischemic Dilated Cardiomyopathy

Abstract

Background Methamphetamine associated cardiomyopathy (MACM) is an increasingly recognized form of dilated cardiomyopathy around the globe which remains poorly characterized. Purpose To compare the clinical characteristics of MACM to those of non-MA associated dilated CM (NMACM). Methods Consecutive patients with MACM presenting to our institution between Jun 2018 and Jan 2019 were prospectively studied and compared to an age and gender matched cohort of dilated non-ischemic CM cases. Results Seventy patients were studied (35 MACM and 35 NMACM). Mean age was similar between groups (49±9 vs. 48±10 years, p=0.465) and 97% of patients were male. Median duration of MA use prior to cardiomyopathy diagnosis was 5 years (range 0-30). Patients were predominantly Hispanic in both groups (48% vs. 62%, p=0.229), but with a greater proportion of Caucasians in the MACM group compared to NMACM (26% vs 6%,p=0.045).MACM was characterized by lower left ventricular ejection fraction (LVEF) and greater left ventricular end diastolic volume (LVEDV) compared to NMACM. RV dilation was present more often in MACM cases (Table). Years of MA use was associated with greater LA volumes (R2= 0.13, p=0.048). Association with larger LVEDV and incidence of RV dilation were borderline significant (R2= 0.11, p=0.054 and p=0.058 respectively). The amount of MA used per week correlated with higher RVSP (R2=0.317, p=0.004). Polysubstance abuse was associated with greater LVEF (p=0.028), lower LVEDV (p=0.037) and lower LV mass (p=0.004). Conclusions MACM is associated with higher degree of LV and RV dilatation as well as LV systolic dysfunction when compared to matched NMACM cases. Years of MA use and amount MA consumed appear to influence severity of disease.