Characteristics of Methamphetamine-associated Cardiomyopathy and the Impact of Methamphetamine Use on Cardiac Dysfunction

Methamphetamine-associated cardiomyopathy (MACM) in an increasingly prevalent disease yet presenting clinical characteristics have not been well studied. We studied consecutive patients with MACM presenting between June 2018 and March 2020 who were interviewed for drug use and medical history. We retrospectively identified an age- and gender-matched cohort of Non-MACM (NMACM) patients and compared clinical characteristics. 140 patients (70 MACM and 70 NMACM) were studied. MACM patients were young (49.6 ± 10 years) and predominantly male (94%). Compared to NMACM, MACM patients were more likely to be Caucasian (21% vs 6%, p = 0.007) and homeless (47% vs 7%, p = 0.001). MACM was characterized by lower left ventricular ejection fraction (EF) (p <0.001) and greater LV end diastolic volume (LVEDV) (p = 0.024). Right ventricular (RV) dilation was present more often (p = s0.001) and was more often severe (p = 0.03). Among MACM cases, half of the cohort developed MACM within 5 years of starting MA (18% within 1 year). There was no apparent relationship between frequency or amount of MA used weekly with time until heart failure onset. Drug use patterns were not clearly related to the degree of LV structural change however there were more consistent, significant associations with RV and right atrial (RA) size parameters. In conclusion, patients with MACM have more severe myocardial impairment with lower EF, greater LVEDV and RV dilation. Drug use patterns do not clearly impact degree of LV structural changes by echocardiography however may be related to RV and RA size.