Comparison of Clinical Characteristics and Outcomes of Patients With Reversible Versus Persistent Methamphetamine-Associated Cardiomyopathy.

Anecdotal cases of reversible methamphetamine-associated cardiomyopathy (rMAC) have been reported, but not well understood. This study sought to determine the clinical characteristics, outcomes and predictors of reversibility among patients with rMAC as compared with patients with persistent MAC (pMAC). We retrospectively studied adult MAC patients with left ventricular ejection fraction (LVEF) ≤40% at a single center between 2004 and 2018. rMAC was defined as increase in LVEF by ≥20 points or to ≥50%. Those with persistent LVEF ≤40% constituted the pMAC group. 357 MAC cases were identified: 250 patients had pMAC and 107 had rMAC. After a median follow-up of 45 months (interquartile range 27 to 70), LVEF increased by 28.3 ± 6.9% in rMAC (p <0.001), whereas it was unchanged in pMAC (Δ: -0.5 ± 8.7%, p = 0.350). Heart failure hospitalizations and New York Heart Association Class III/IV heart failure were both significantly reduced for rMAC than the pMAC group. All-cause mortality was 21.6% overall, 28% in pMAC and 6.5% in the rMAC group (p <0.001). Kaplan-Meier survival curves demonstrated significantly higher cumulative survival for rMAC (Log Rank p <0.001). Multivariable logistic regression identified MA cessation (odds ratio/OR: 4.23, 95% confidence interval/CI: 2.47 to 7.38, p <0.001) and baseline right ventricular end systolic area (OR: 0.92, 95% CI: 0.87 to 0.97, p = 0.001) as strongly predictive of MAC reversal. In conclusion, MAC reversal is not uncommon and is associated with significant clinical improvement including reduced mortality. It can be facilitated by MA cessation when the cardiac chambers, especially the right ventricle, are not severely dilated.