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

Cardiomyopathy in Patients With Acute Ischemic Stroke and Methamphetamine Use: Relevance for Cardioembolic Stroke and Outcome

BACKGROUND

Methamphetamine use has emerged as a major risk factor for cardiovascular and cerebrovascular disease in young adults. The aim of this study was to investigate a possible association of methamphetamine use with cardioembolic stroke.

METHODS AND RESULTS

We performed a retrospective study of patients with acute ischemic stroke admitted at our medical center between 2019 and 2022. All patients were screened for methamphetamine use and cardiomyopathy, defined as left ventricular ejection fraction ≤45%. Among 938 consecutive patients, 46 (4.9%) were identified as using methamphetamine. Compared with the nonmethamphetamine group (n=892), the methamphetamine group was significantly younger (52.8±9.6 versus 69.7±15.2 years; P<0.001), included more men (78.3% versus 52.8%; P<0.001), and had a significantly higher rate of cardiomyopathy (30.4% versus 14.0%; P<0.01). They were also less likely to have a history of atrial fibrillation (8.7% versus 33.4%; P<0.01) or hyperlipidemia (28.3% versus 51.7%; P<0.01). Compared with patients with cardiomyopathy without methamphetamine use, the patients with cardiomyopathy with methamphetamine use had significantly lower left ventricular ejection fraction (26.0±9.59% versus 32.47±9.52%; P<0.01) but better functional outcome at 3 months, likely attributable to significantly younger age and fewer comorbidities. In the logistic regression model of clinical variables, methamphetamine-associated cardiomyopathy was found to be significantly associated with cardioembolic stroke (odds ratio, 1.79 [95% CI, 1.04-3.06]; P<0.05).

CONCLUSIONS

We demonstrate that methamphetamine use is significantly associated with cardiomyopathy and cardioembolic stroke in young adults.

Methamphetamine-associated heart failure: a systematic review of observational studies

OBJECTIVE

To conduct a systematic review of observational studies on methamphetamine-associated heart failure (MethHF) .

METHODS

Six databases were searched for original publications on the topic. Title/abstract and included full-text publications were reviewed in duplicate. Data extraction and critical appraisal for risk of bias were performed in duplicate.

RESULTS

Twenty-one studies are included in the final analysis. Results could not be combined because of heterogeneity in study design, population, comparator, and outcome assessment. Overall risk of bias is moderate due to the presence of confounders, selection bias and poor matching; overall certainty in the evidence is very low. MethHF is increasing in prevalence, affects diverse racial/ethnic/sociodemographic groups with a male predominance; up to 44% have preserved left-ventricular ejection fraction. MethHF is associated with significant morbidity including worse heart failure symptoms compared with non-methamphetamine related heart failure. Female sex, methamphetamine abstinence and guideline-directed heart failure therapy are associated with improved outcomes. Chamber dimensions on echocardiography and fibrosis on biopsy predict the extent of recovery after abstinence.

CONCLUSIONS

The increasing prevalence of MethHF with associated morbidity underscores the urgent need for well designed prospective studies of people who use methamphetamine to accurately assess the epidemiology, clinical features, disease trajectory and outcomes of MethHF. Methamphetamine abstinence is an integral part of MethHF treatment; increased availability of effective non-pharmacological interventions for treatment of methamphetamine addiction is an essential first step. Availability of effective pharmacological treatment for methamphetamine addiction will further support MethHF treatment. Using harm reduction principles in an integrated addiction/HF treatment programme will bolster efforts to stem the increasing tide of MethHF.

Mitochondrial dysfunction and autophagy activation are associated with cardiomyopathy developed by extended methamphetamine self-administration in rats

The recent rise in illicit use of methamphetamine (METH), a highly addictive psychostimulant, is a huge health care burden due to its central and peripheral toxic effects. Mounting clinical studies have noted that METH use in humans is associated with the development of cardiomyopathy; however, preclinical studies and animal models to dissect detailed molecular mechanisms of METH-associated cardiomyopathy development are scarce. The present study utilized a unique very long-access binge and crash procedure of METH self-administration to characterize the sequelae of pathological alterations that occur with METH-associated cardiomyopathy. Rats were allowed to intravenously self-administer METH for 96 h continuous weekly sessions over 8 weeks. Cardiac function, histochemistry, ultrastructure, and biochemical experiments were performed 24 h after the cessation of drug administration. Voluntary METH self-administration induced pathological cardiac remodeling as indicated by cardiomyocyte hypertrophy, myocyte disarray, interstitial and perivascular fibrosis accompanied by compromised cardiac systolic function. Ultrastructural examination and native gel electrophoresis revealed altered mitochondrial morphology and reduced mitochondrial oxidative phosphorylation (OXPHOS) supercomplexes (SCs) stability and assembly in METH exposed hearts. Redox-sensitive assays revealed significantly attenuated mitochondrial respiratory complex activities with a compensatory increase in pyruvate dehydrogenase (PDH) activity reminiscent of metabolic remodeling. Increased autophagy flux and increased mitochondrial antioxidant protein level was observed in METH exposed heart. Treatment with mitoTEMPO reduced the autophagy level indicating the involvement of mitochondrial dysfunction in the adaptive activation of autophagy in METH exposed hearts. Altogether, we have reported a novel METH-associated cardiomyopathy model using voluntary drug seeking behavior. Our studies indicated that METH self-administration profoundly affects mitochondrial ultrastructure, OXPHOS SCs assembly and redox activity accompanied by increased PDH activity that may underlie observed cardiac dysfunction.

Dapagliflozin Protects Methamphetamine-Induced Cardiomyopathy by Alleviating Mitochondrial Damage and Reducing Cardiac Function Decline in a Mouse Model

Background: Methamphetamine (METH)-induced cardiovascular toxicity has been attributed to its destructive effect on mitochondrial function at least to some extent. Previous studies highlighted the benefits of dapagliflozin (DAPA) on the cardiovascular system, but the response of METH-induced cardiomyopathy to DAPA is never addressed before. The present study aimed to investigate the potential ability of DAPA in preventing METH-induced cardiomyopathy.

Materials and Methods: C57BL/6 mice were randomly divided into control group (n = 24), METH group (n = 24), and METH + DAPA group (n = 24). The METH-induced cardiomyopathy group received intraperitoneal METH injections at gradually increasing doses thrice weekly for 14 weeks. Mice in the METH + DAPA group were simultaneously treated with DAPA 1 mg/kg/day by intragastric administration. Echocardiography was performed to assess cardiac function. Reactive oxygen species (ROS), JC-1, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were performed to evaluate oxidative stress, mitochondrial damage, and apoptosis, respectively. Mitochondrial and apoptosis-related protein expression was measured by western blotting.

Results: Mice exposed to METH exhibited reduced cardiac function (left ventricular ejection fraction [LVEF]: 56.51 ± 6.49 vs. 73.62 ± 1.42, p &lt; 0.01), fibrotic remodeling, and mitochondrial dysfunction, leading to apoptosis (apoptotic cells%: 7.4 ± 1.3 vs. 1.3 ± 0.5, p &lt; 0.01). DAPA significantly reduced mitochondrial dynamics and function, ROS, apoptosis (apoptotic cells%: 2.4 ± 0.8 vs. 7.4 ± 1.3, p &lt; 0.01), cardiac function decline (LVEF: 70.99 ± 4.936 vs. 56.51 ± 6.49, p &lt; 0.01), and fibrotic remodeling. These results indicated that DAPA could be considered as an effective therapeutic agent in the protection against METH-associated cardiomyopathy.

Conclusion: DAPA protects against METH-induced cardiomyopathy in mice by decreasing mitochondrial damage and apoptosis.

A Comprehensive Approach to Managing Methamphetamine-Associated Cardiomyopathy

Methamphetamines are illicit drugs of the amphetamine-type stimulant class that have been increasing in popularity, availability, and purity in recent decades. As a result, rates of methamphetamine-associated cardiomyopathy (MAC) are rising globally. MAC is associated with high rates of sudden cardiac arrest, late presentation, and poor outcomes. This review discusses the medical management of MAC, including anticipated challenges specific to methamphetamine users. Not only are patients with MAC more likely to present at a younger age and with multisystem disease than patients with cardiomyopathy of other etiologies, but there may also be significant behavioral, psychosocial, financial, and system-based challenges to providing the best medical care. An individualized treatment plan that emphasizes methamphetamine abstinence as the foundation of therapy, as well as introducing optimal heart failure therapy and providing multidisciplinary support is likely to result in optimal outcomes. Given the potential reversibility of MAC, institution of guideline-directed heart failure therapy and patient support for adherence to therapy and abstinence from methamphetamines should be energetically pursued.