Cardiac lesions and their reversibility after long term administration of methamphetamine

Trends in peripheral artery disease and critical limb ischemia hospitalizations among cocaine and methamphetamine users in the United States: a nationwide study

Background

Peripheral artery disease (PAD) is on the rise worldwide, ranking as the third leading cause of atherosclerosis-related morbidity; much less is known about its trends in hospitalizations among methamphetamine and cocaine users.

Objectives

We aim to evaluate the overall trend in the prevalence of hospital admission for PAD with or without the use of stimulant abuse (methamphetamine and cocaine) across the United States. Additionally, we evaluated the PAD-related hospitalizations trend stratified by age, race, sex, and geographic location.

Methods

We used the National Inpatient Sample (NIS) database from 2008 to 2020. The Cochran Armitage trend test was used to compare the trend between groups. Multivariate logistic regression was used to examine adjusted odds for PAD and CLI hospitalizations among methamphetamine and cocaine users.

Results

Between 2008 and 2020, PAD-related hospitalizations showed an increasing trend in Hispanics, African Americans, and western states, while a decreasing trend in southern and Midwestern states (p-trend <0.05). Among methamphetamine users, an overall increasing trend was observed in men, women, western, southern, and midwestern states (p-trend <0.05). However, among cocaine users, PAD-related hospitalization increased significantly for White, African American, age group >64 years, southern and western states (p-trend <0.05). Overall, CLI-related hospitalizations showed an encouraging decreasing trend in men and women, age group >64 years, and CLI-related amputations declined for women, White patient population, age group >40, and all regions (p-trend <0.05). However, among methamphetamine users, a significantly increasing trend in CLI-related hospitalization was seen in men, women, White & Hispanic population, age group 26-45, western, southern, and midwestern regions.

Conclusions

There was an increasing trend in PAD-related hospitalizations among methamphetamine and cocaine users for both males and females. Although an overall decreasing trend in CLI-related hospitalization was observed for both genders, an up-trend in CLI was seen among methamphetamine users. The upward trends were more prominent for White, Hispanic & African Americans, and southern and western states, highlighting racial and geographic variations over the study period.

Consecutive treatments of methamphetamine promote the development of cardiac pathological symptoms in zebrafish

Chronic methamphetamine use, a widespread drug epidemic, has been associated with cardiac morphological and electrical remodeling, leading to the development of numerous cardiovascular diseases. While methamphetamine has been documented to induce arrhythmia, most results originate from clinical trials from users who experienced different durations of methamphetamine abuse, providing no documentation on the use of methamphetamine in standardized settings. Additionally, the underlying molecular mechanism on how methamphetamine affects the cardiovascular system remains elusive. A relationship was sought between cardiotoxicity and arrhythmia with associated methamphetamine abuse in zebrafish to identify and to understand the adverse cardiac symptoms associated with methamphetamine. Zebrafish were first treated with methamphetamine 3 times a week over a 2-week duration. Immediately after treatment, zebrafish underwent electrocardiogram (ECG) measurement using an in-house developed acquisition system for electrophysiological analysis. Subsequent analyses of cAMP expression and Ca2+ regulation in zebrafish cardiomyocytes were conducted. cAMP is vital to development of myocardial fibrosis and arrhythmia, prominent symptoms in the development of cardiovascular diseases. Ca2+ dysregulation is also a factor in inducing arrhythmias. During the first week of treatment, zebrafish that were administered with methamphetamine displayed a decrease in heart rate, which persisted throughout the second week and remained significantly lower than the heart rate of untreated fish. Results also indicate an increased heart rate variability during the early stage of treatment followed by a decrease in the late stage for methamphetamine-treated fish over the duration of the experiment, suggesting a biphasic response to methamphetamine exposure. Methamphetamine-treated fish also exhibited reduced QTc intervals throughout the experiment. Results from the cAMP and Ca2+ assays demonstrate that cAMP was upregulated and Ca2+ was dysregulated in response to methamphetamine treatment. Collagenic assays indicated significant fibrotic response to methamphetamine treatment. These results provide potential insight into the role of methamphetamine in the development of fibrosis and arrhythmia due to downstream effectors of cAMP.

Cardiovascular magnetic resonance imaging characteristics in patients with methamphetamine-associated cardiomyopathy

BACKGROUND

Methamphetamine-associated cardiomyopathy (MA-CMP) is an increasingly recognised aetiology of cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a specialised cardiac imaging modality commonly used in assessment of cardiomyopathy. We aimed to identify specific CMR features associated with MA-CMP.

METHODS

A retrospective cohort study of CMR scans was performed in a single centre between January 2015 and December 2020. Thirty patients with MA-CMP who had undergone CMR were identified. MA-CMP was defined as those with a history of significant methamphetamine use hospitalised with acute decompensated heart failure (other causes of cardiomyopathy excluded). A retrospective analysis of index admission CMRs was performed. All studies were performed on a 1.5 T CMR scanner.

RESULTS

The mean age of MA-CMP patients was 43.7 ± 7.5 years, and 86.7% were male. The mean left ventricular (LV) volume obtained in this cohort was consistent with severe LV dilatation (LV end-diastolic volume (334 ± 99 ml); LV end-systolic volume: 269 ± 98 ml), whilst the right ventricular (RV) volume indicated moderate-to-severe dilatation (RV end-diastolic volume: 272 ± 91 ml; RV end-systolic volume: 173 ± 82 ml). Mean LV ejection fraction (20.9 ± 9.2%) indicated severe LV dysfunction, with moderate-to-severe RV dysfunction also detected (RV ejection fraction: 29.4 ± 13.4%). 22 patients (73.3%) had myocardial late gadolinium enhancement (LGE), of which 59.1% were located in the mid-wall, with all of these involving the interventricular septum. 22.7% displayed localised regions of sub-endocardial LGE in a variety of locations, and 18.2% had transmural regions of LGE that were located in the inferior and inferolateral segments. 6 patients (20%) had intracardiac thrombus (4 LV, 2 both LV and RV).

CONCLUSION

MA-CMP was associated with severe biventricular dilatation and dysfunction, with a high prevalence of intraventricular thrombus. This cohort study highlights that MA-CMP patients have a high prevalence of CMR findings.

Methamphetamine Dysregulation of the Central Nervous System and Peripheral Immunity

Methamphetamine (METH) is a potent psychostimulant that increases extracellular monoamines, such as dopamine and norepinephrine, and affects multiple tissue and cell types in the central nervous system (CNS) and peripheral immune cells. The reinforcing properties of METH underlie its significant abuse potential and dysregulation of peripheral immunity and central nervous system functions. Together, the constellation of METH's effects on cellular targets and regulatory processes has led to immune suppression and neurodegeneration in METH addicts and animal models of METH exposure. Here we extensively review many of the cell types and mechanisms of METH-induced dysregulation of the central nervous and peripheral immune systems. SIGNIFICANCE STATEMENT: Emerging research has begun to show that methamphetamine regulates dopaminergic neuronal activity. In addition, METH affects non-neuronal brain cells, such as microglia and astrocytes, and immunological cells of the periphery. Concurrent disruption of bidirectional communication between dopaminergic neurons and glia in the CNS and peripheral immune cell dysregulation gives rise to a constellation of dysfunctional neuronal, cell, and tissue types. Therefore, understanding the pathophysiology of METH requires consideration of the multiple targets at the interface between basic and clinical neuroscience.

Environmental concentration of methamphetamine induces pathological changes in brown trout (Salmo trutta fario)

Methamphetamine, mainly consumed as an illicit drug, is a potent addictive psychostimulant that has been detected in surface water at concentrations ranging from nanograms to micrograms per litre, especially in Middle and East Europe. The aim of this study was to expose brown trout (Salmo trutta fario) to environmental (1 μg L^-1) and higher (50 μg L^-1) concentrations of methamphetamine for 35 days with a four-day depuration phase to assess the possible negative effects on fish health. Degenerative liver and heart alterations, similar to those described in mammals, were observed at both concentrations, although at different intensities. Apoptotic changes in hepatocytes, revealed by activated caspase-3, were found in exposed fish. The parent compound and a metabolite (amphetamine) were detected in fish tissues in both concentration groups, in the order of kidney > liver > brain > muscle > plasma. Bioconcentration factors ranged from 0.13 to 80. A therapeutic plasma concentration was reached for both compounds in the high-concentration treatment. This study indicates that chronic environmental concentrations of methamphetamine can lead to health issues in aquatic organisms.

The emergence of cardiac changes following the self-administration of methamphetamine

BACKGROUND

Clinical observations suggest an association between methamphetamine (METH) use and cardiovascular disease, but preclinical studies are lacking. The purpose of the current study was to explore changes in left ventricular function as a potential precursor to cardiovascular disease in a rodent model of METH use.

METHODS

Male rats were allowed to self-administer either METH or saline for 9 d. On the day following the 4th and 9th self-administration sessions, an echocardiogram was performed to assess left-ventricular parameters under basal conditions and following a low-dose of METH (1 mg/kg).

RESULTS

A low challenge dose of METH resulted in subtle but statistically significant changes in cardiac function during the echocardiogram in both the METH and saline self-administering groups. Further, differences in left-ventricular parameters such as stroke volume and heart rate were observed between METH and saline groups following the 9th self-administration session. Finally, supervised machine learning correctly predicted the self-administration group assignment (saline or METH) using cardiac parameters following the 9th self-administration session.

CONCLUSIONS

The findings of the current study suggest the heart, specifically the left ventricle, is sensitive to METH. Overall, these findings and emerging clinical observations highlight the need for research to investigate the effects of METH use on the heart.

Clinical Characteristics and Management of Methamphetamine-Associated Cardiomyopathy: State-of-the-Art Review

Methamphetamine‐associated cardiomyopathy (MACM) is an increasingly recognized disease entity in the context of a rapidly spreading methamphetamine epidemic. MACM may afflict individuals with a wide range of ages and socioeconomic backgrounds. Presentations can vary greatly and may involve several complications unique to the disease. Given the public health significance of this disease, there is a relative dearth of consensus material to guide clinicians in understanding, diagnosing, and managing MACM. This review therefore aims to: (1) describe pathologic mechanisms of methamphetamine as they pertain to the development, progression, and prognosis of MACM, and the potential to recover cardiac function; (2) summarize existing data from epidemiologic studies and case series in an effort to improve recognition and diagnosis of the disease; (3) guide short‐ and long‐term management of MACM with special attention to expected or potential sequelae of the disease; and (4) highlight pivotal unanswered questions in need of urgent investigation from a public health perspective.

Methamphetamine-related cardiovascular diseases

Aims

Abuse of crystal methamphetamine (MA) poses a growing problem for health services worldwide. This review summarizes the current literature on the effects of MA on the cardiovascular system.

Methods and results

This article is a presentation of a case report and review of the current literature. In Europe, especially the eastern countries and the eastern states of Germany are affected. MA increases the concentration of catecholamines in the synaptic gap leading to euphoria, alertness, and hunger suppression as well as psychiatric and gastrointestinal complications. MA consumption is associated with hypertension, acute and chronic myocardial toxicity, stroke, coronary artery disease, and sudden cardiac death. Although many aspects of the underlying pathophysiology remain unknown, catecholamine‐mediated pathologies appear to play an important role. The duration of MA consumption is the most important determinant for the prognosis.

Conclusions

Awareness is needed as cardiac complications are important causes of morbidity and mortality in patients with MA consumption. Drug abstinence is the mainstay of therapy, cardiac and other complications should be treated according to the respective guidelines. Incompliance to therapy and frequent relapses are the main challenges for successful treatment. Further research is required to improve the understanding of this rapidly increasing cardiomyopathy.

Psychostimulant use disorder and the heart

Psychostimulants are a diverse range of substances that encompass cocaine and the phenylethylamines, the latter including the amphetamines, cathinones and some 'novel psychoactive substances'. This paper examines the range of pathophysiological processes, clinical presentations and treatment options involving the heart and cardiovascular system both in the acute setting and where long-term effects of psychostimulant use have affected the cardiovascular system. A common feature of these drugs is their effect on the cardiovascular system, where their major action is that of sympathomimetic amines with short- and long-term stimulation of the adrenergic system and consequent effects on blood pressure, cardiac modelling, atherogenesis and cellular calcium signalling. Cocaine additionally exhibits a variety of prothrombotic effects, effects on inflammatory mediators and alterations in myocardial gene expression. Persistent psychostimulant use results in progressive cardiovascular pathology, largely in the form of accelerated atherosclerosis, hypertension and myocardial ischaemia. Abstinence results in at least partial reversal of pathology. To a large extent, an assumption is made that treatment protocols used for cocaine-associated cardiovascular pathology apply to the amphetamines and other phenylethylamines, but there appears to be little research in this area, despite acknowledgement that cocaine and the better-known amphetamines have different modes of action.

Characteristics and Outcomes of Methamphetamine Abuse Among Veterans With Heart Failure

Methamphetamine is one of the most commonly abused illicit substances worldwide. Chronic methamphetamine abuse (MA) is associated with the development of a dilated cardiomyopathy. MA in patients with heart failure (MethHF) is increasingly reported yet poorly characterized. This was a retrospective cohort study of veterans treated at the VA Medical Center in San Diego between 2005 and 2015 with a diagnosis of HF and a history of MA. The incidence of MA each year was calculated, and clinical characteristics and outcomes of veterans with HF with and without MA were compared. Among 9,491 veterans with HF, 429 were identified as having a history of MA. Between 2006 and 2015, the incidence of MA in veterans with HF doubled from 3.44% to 6.70%. Of the 429 identified, 106 veterans had a hospitalization for HF and they were compared with veterans with HF without evidence of MA (HF). Compared with veterans with HF, veterans with MethHF were significantly younger (60.7 ± 7.3 vs 71.6 ± 11.6 years, p <0.001), with more frequent co-morbid post-traumatic stress disorder (16.8% vs 4.4%, p = 0.006), depression (28.7% vs 11.0%, p = 0.002), homelessness (27.9% vs 8.9%, p = 0.001), and unemployment (55.8% vs 30.0%, p <0.001). Despite their younger age, veterans with MethHF had high rates of HF readmission or emergency room visit (49% vs 38% in MethHF vs HF, p = 0.34) and mortality at 6 months (27% vs 38% in MethHF vs HF, p = 0.10) compared with HF. In conclusion, MA in veterans with HF is on the rise. Certain demographic and clinical characteristics of veterans with MethHF may contribute to their poor outcomes.

Cardiac and Systemic Thrombus Caused by Drug Abuse

Drug abuse is an increasing concern all over the world especially in the United States. Methamphetamine have been well established to cause elevated body temperature, irregular heartbeat, seizures, and heart disease. We present a case of ventricular thrombus with systemic emboli in a patient with dilated cardiomyopathy after methamphetamine use.

Methamphetamine produces cardiac damage and apoptosis by decreasing melusin

Methamphetamine (METH) is an amphetamine-type drug that is highly addictive and widely abused. Many studies have shown that METH exposure causes severe damage not only to the nervous system but also to the cardiovascular system. Melusin protein is a mechanotransducer that plays an important role in maintaining normal heart function. However, the role of melusin in METH-induced cardiotoxicity has not yet been reported. We hypothesized that methamphetamine can produce cardiac damage and apoptosis by decreasing the quantity of melusin. To test this hypothesis, we determined the protein expression of melusin and apoptosis markers in METH-treated rats and primary rat cardiomyocytes. We also established a melusin-overexpressing cell model to assess the importance of melusin in maintaining antiapoptotic pathways. To confirm our findings from the in vitro and animal models, we also evaluated the apoptotic index of cardiomyocytes and the protein expression of apoptotic markers in postmortem heart tissues from deceased METH abusers and age-matched control subjects. The results showed that the apoptosis of cardiomyocytes was increased significantly and that the protein expression of melusin was decreased after exposure to METH in primary rat cardiomyocytes, in rats and in humans. METH treatment also decreased the expression of the downstream proteins FAK, IQGAP1, p-AKT, p-GSK3β, and p-ERK in primary rat cardiomyocytes and in vivo. After overexpression of melusin, the above effects were partially reversed in primary rat cardiomyocytes. We conclude that METH can produce cardiac damage and apoptosis by decreasing melusin, while melusin-activated signaling by phosphorylated AKT, phosphorylated GSK3β, and ERK may be resistant to methamphetamine-induced myocardial apoptosis.

Postoperative catecholamine resistance following fetal methamphetamine exposure

Methamphetamine and its related compounds are among the most widely abused recreational drugs worldwide. While a myriad of clinical complications of methamphetamine use have been described, there is a paucity of literature regarding the effects of maternal abuse during pregnancy on neonatal hearts. In this report, we describe a neonate who underwent Norwood-type palliation and subsequently developed catecholamine-resistant cardiogenic shock, likely related to methamphetamine exposure, which recovered after a period of venoarterial extracorporeal membrane oxygenation support.

Exposure to Amphetamines Leads to Development of Amphetamine Type Stimulants Associated Cardiomyopathy (ATSAC)

With rapidly rising prevalence of exposure to Amphetamine Type Stimulants (ATS), novel insights into cardiotoxic effects of this substance are being presented in the literature and remarkably ATS Associated Cardiomyopathy (ATSAC) is emerging as a novel cardiovascular condition with its distinctive pathogenesis, risk factors, clinical features and prognosis. A comprehensive systematic review was performed to explore and analyze the current evidence on the association between ATS exposure and development of cardiomyopathy, biological mechanisms involved in pathogenesis of ATSAC, risk factors, clinical features and course of patients with ATSAC. Several animal studies, case reports, case series and case-control studies support the association between ATS exposure and ATSAC. Oxidative stress, accelerated apoptosis, increased p53 activity, cardiomyocyte necrosis, perfusion defects, fatty acid toxicity, altered gene expression, abnormal cardiac protein synthesis and function in addition to defects in intracellular calcium hemostasis present themselves as likely mechanisms of cardiotoxicity in ATSAC. Majority of patients with ATSAC were found to be male, young and presented late with severe dilated cardiomyopathy. Female ATS users predominantly develop Takotsubo type of ATSAC and in particular its atypical basal variant. Overall, cessation of ATS exposure seems to be associated with some degree of reversibility and recovery in ATSAC sufferers.

Histopathological study of cardiac lesions in methamphetamine poisoning-related deaths

BACKGROUND

Methamphetamine abuse is a worldwide health concern. Methamphetamine causes health hazards in many vital organs. It can cause damage to cardiac tissue via catecholamines release. Methamphetamine related deaths are becoming one of the most important problems in Iran. The purpose of the present study was to determine cardiac pathology in methamphetamine poisoning-related deaths.

METHODS

The study included 100 cases of methamphetamine poisoning-related deaths and 100 cases as control group. Toxicology analysis of liver, gastric content, bile, urine, blood and vitreous humor were conducted to detect drugs, poisons and alcohols using thin layer chromatography, gas chromatography/mass spectrometry, and high performance liquid chromatography. Positive toxicology analysis results except for amphetamine and methamphetamine were excluded from the study in order to omit interfering factors. The most striking features of cardiac damage were observed by light microscopy.

RESULTS

Methamphetamine and amphetamine were detected in either urine or gastric content samples. In all of the cases methamphetamine toxicity was determined to be a direct cause of death by forensic medicine practitioner. Cardiovascular pathology was noted in 68% of studied cases. The most common histopathologic features were myocardial fiber hypertrophy, mild, moderate to severe atherosclerosis and focal degeneration/necrosis.

CONCLUSION

The results of the present study indicate that cardiotoxicity is one of the major contributing factors in methamphetamine poisoning related deaths. Overall, the current study highlights the fact that cardiotoxic effects of methamphetamine can explain increasing reports of heart failure and consequently death in young abusers.

TRIAL REGISTRATION

Not applicable. Histopathological study of cardiac lesions in methamphetamine poisoning-related deaths.

Frequency of Methamphetamine Use as a Major Contributor Toward the Severity of Cardiomyopathy in Adults ≤50 Years

Methamphetamine is one of the most commonly abused illegal drugs in the United States. Health care providers are commonly faced with medical illness caused by methamphetamine. This study investigates the impact of methamphetamine use on the severity of cardiomyopathy and heart failure in young adults. This retrospective study analyzed patients seen at Arrowhead Regional Medical Center from 2008 to 2012. Patients were between 18 and 50 years old. All patients had a discharge diagnosis of cardiomyopathy or heart failure. The severity of disease was quantified by left ventricular systolic dysfunction: heart failure with preserved ejection fraction to mildly reduced if ejection fraction was >40% and moderate to severely depressed if ejection fraction was ≤40%. Methamphetamine abuse was determined by a positive urine drug screen or per documented history. Of the 590 patients, 223 (37.8%) had a history of methamphetamine use. More than half the population was men (n = 389, 62.3%); 41% was Hispanic (n = 243), 25.8% was Caucasian (n = 152), and 27.8% was African-American (n = 164); 60.9% were in the age range of 41 to 50 years (n = 359). Patients with a history of methamphetamine use had increased odds (odds ratio = 1.80, 95% confidence interval 1.27 to 2.57) of having a moderately or severely reduced ejection fraction. Additionally, men were more likely (odds ratio 3.13, 95% confidence interval 2.14 to 4.56) to have worse left ventricular systolic dysfunction. In conclusion, methamphetamine use was associated with an increased severity of cardiomyopathy in young adults.

Nupr1/Chop signal axis is involved in mitochondrion-related endothelial cell apoptosis induced by methamphetamine

Methamphetamine (METH) abuse has been a serious global public health problem for decades. Previous studies have shown that METH causes detrimental effects on the nervous and cardiovascular systems. METH-induced cardiovascular toxicity has been, in part, attributed to its destructive effect on vascular endothelial cells. However, the underlying mechanism of METH-caused endothelium disruption has not been investigated systematically. In this study, we identified a novel pathway involved in endothelial cell apoptosis induced by METH. We demonstrated that exposure to METH caused mitochondrial apoptosis in human umbilical vein endothelial cells and rat cardiac microvascular endothelial cells in vitro as well as in rat cardiac endothelial cells in vivo. We found that METH mediated endothelial cell apoptosis through Nupr1–Chop/P53–PUMA/Beclin1 signaling pathway. Specifically, METH exposure increased the expression of Nupr1, Chop, P53 and PUMA. Elevated p53 expression raised up PUMA expression, which initiated mitochondrial apoptosis by downregulating antiapoptotic Bcl-2, followed by upregulation of proapoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. Interestingly, increased Beclin1, upregulated by Chop, formed a ternary complex with Bcl-2, thereby decreasing the dissociative Bcl-2. As a result, the ratio of dissociative Bcl-2 to Bax was also significantly decreased, which led to translocation of cyto c and initiated more drastic apoptosis. These findings were supported by data showing METH-induced apoptosis was significantly inhibited by silencing Nupr1, Chop or P53, or by PUMA or Beclin1 knockdown. Based on the present data, a novel mechanistic model of METH-induced endothelial cell toxicity is proposed. Collectively, these results highlight that the Nupr1–Chop/P53–PUMA/Beclin1 pathway is essential for mitochondrion-related METH-induced endothelial cell apoptosis and may be a potential therapeutic target for METH-caused cardiovascular toxicity. Future studies using knockout animal models are warranted to substantiate the present findings.

The Cardiac Complications of Methamphetamines

Methamphetamines are increasingly popular drugs of abuse in Australia, and are rising in purity. The rising popularity and purity of methamphetamines has notably increased demands upon Australian medical services. Methamphetamines are sympathomimetic amines with a range of adverse effects upon multiple organ systems. Cardiovascular complications are the second leading cause of death in methamphetamine abusers, and there appears to be a high prevalence of cardiac pathology. Cardiovascular pathology frequently seen in methamphetamine abusers includes hypertension, aortic dissection, acute coronary syndromes, pulmonary arterial hypertension and methamphetamine-associated cardiomyopathy. The rising prevalence of methamphetamine abuse is likely to increase the burden of cardiovascular pathology in Australians. A National Parliamentary Enquiry was opened in March 2015 to address concerns regarding the medical and social impacts of methamphetamine abuse. From April 2015, a National 'Ice Taskforce' was also created in parallel. Reversal of cardiac pathology appears to be achievable with abstinence from methamphetamines and initiation of appropriate treatment. It is key to appreciate that the pathogenesis of methamphetamine-induced cardiac complications arises as a result of the specific toxic effects of methamphetamines. Clinical management is hence individualised; suggested management approaches for methamphetamine-induced cardiac complications are detailed within this article.

Methamphetamine and HIV-Tat alter murine cardiac DNA methylation and gene expression

This study addresses the individual and combined effects of HIV-1 and methamphetamine (N-methyl-1-phenylpropan-2-amine, METH) on cardiac dysfunction in a transgenic mouse model of HIV/AIDS. METH is abused epidemically and is frequently associated with acquisition of HIV-1 infection or AIDS. We employed microarrays to identify mRNA differences in cardiac left ventricle (LV) gene expression following METH administration (10d, 3mg/kg/d, subcutaneously) in C57Bl/6 wild-type littermates (WT) and Tat-expressing transgenic (TG) mice. Arrays identified 880 differentially expressed genes (expression fold change>1.5, p<0.05) following METH exposure, Tat expression, or both. Using pathway enrichment analysis, mRNAs encoding polypeptides for calcium signaling and contractility were altered in the LV samples. Correlative DNA methylation analysis revealed significant LV DNA methylation changes following METH exposure and Tat expression. By combining these data sets, 38 gene promoters (27 related to METH, 11 related to Tat) exhibited differences by both methods of analysis. Among those, only the promoter for CACNA1C that encodes L-type calcium channel Cav1.2 displayed DNA methylation changes concordant with its gene expression change. Quantitative PCR verified that Cav1.2 LV mRNA abundance doubled following METH. Correlative immunoblots specific for Cav1.2 revealed a 3.5-fold increase in protein abundance in METH LVs. Data implicate Cav1.2 in calcium dysregulation and hypercontractility in the murine LV exposed to METH. They suggest a pathogenetic role for METH exposure to promote LV dysfunction that outweighs Tat-induced effects.

The effect of methamphetamine on an animal model of erectile function

In the US methamphetamine is considered a first-line treatment for attention-deficit hyperactivity disorder. It is also a common drug of abuse. Reports in patients and abusers suggest its use results in impotence. The efficacy of phosphodiesterase-5 inhibitors (PDE5i) to restore erectile function in these patient groups also has not been determined. In these studies, we determined if the rat is a suitable animal model for the physiological effects of methamphetamine on erectile function, and if a PDE5i (tadalafil) has an effect on erectile function following methamphetamine treatment. In acute phase studies, erectile function was measured in male Sprague-Dawley rats, before and after administration of 10 mg/kg methamphetamine i.p. Chronically treated animals received escalating doses of methamphetamine [2.5 mg/kg (1st week), 5 mg/kg (2nd week), and 10 mg/kg (3rd week)] i.p. daily for 3 weeks and erectile function compared with untreated controls. The effect of co-administration of tadalafil was also investigated in rats acutely and chronically treated with methamphetamine. Erectile function was determined by measuring the intracorporal pressure/blood pressure ratio (ICP/BP) following cavernous nerve stimulation. In both acute and chronic phase studies, we observed a significant increase in the rates of spontaneous erections after methamphetamine administration. In addition, following stimulation of the cavernous nerve at 4 and 6 mA, there was a significant decrease in the ICP/BP ratio (approximately 50%), indicative of impaired erectile function. Tadalafil treatment reversed this effect. In chronically treated animals, the ICP/BP ratio following 4 and 6 mA stimulation decreased by approximately 50% compared with untreated animals and erectile dysfunction (ED) was also reversed by tadalafil. Overall, our data suggest that the rat is a suitable animal model to study the physiological effect of methamphetamine on erectile function. Our work also provides a rationale for treating patients that report ED associated with therapeutics-containing methamphetamine or amphetamine with PDE5i.

Distinct effects of methamphetamine on autophagy-lysosome and ubiquitin-proteasome systems in HL-1 cultured mouse atrial cardiomyocytes

The aim of this study is to investigate the molecular mechanism underling the cardiotoxicity of methamphetamine, a psychostimulant drug that is currently abused in the world. A mouse atrial cardiac cell line, HL-1, which retains phenotypes of cardiac cells and serves as a useful model for examining cardiac pathophysiology, was used for this purpose. During treatment with 1mM methamphetamine (MAP) for 3-48h, massive but transient cytoplasmic vacuolization (3-12h) followed by an intracellular accumulation of granules (24-48h) was observed under light microscopy. The vacuoles were surrounded by the lysosome membrane marker LAMP1, while the granules colocalized with the autophagy markers LC3 and p62 as well as ubiquitinated proteins. Western blot analysis showed that LC3 was activated during MAP administration, although p62 was not degraded but rather accumulated. Concordant with p62 accumulation, the nuclear translocation of an anti-oxidative transcription factor, Nrf2, and the subsequent induction of its target gene, HO-1, was observed, suggesting an impairment of autophagic protein degradation and the subsequent activation of the p62/Nrf2/HO-1 pathway. In addition, proteomic analysis revealed a reduction in myosin heavy chain (MHC) protein levels during MAP administration. The ubiquitination of MHC and the induction of the muscle sarcomere protein-specific E3 ubiquitin ligases MuRF1 and atrogin-1 were proved by immunoprecipitation and quantitative real-time PCR, respectively. Taken together, the vacuolization of lysosomes and the subsequent accumulation of autophagosomes indicate an impairment of autophagic protein degradation during MAP administration; on the other hand, the ubiquitination and subsequent degradation of MHC indicate the proper progression of proteasomal degradation.

Report of methamphetamine use and cardiomyopathy in three patients

Background

Methamphetamine (meth) is a stimulant used illegally around the world, including in Iran. Cardiomyopathy and cardiac failure may occur following chronic meth use and may cause the patients referred to the emergency department.

Case reports

A 28-year old man and two women, ages 29 and 31-year-old, with a history of meth use, were admitted to the emergency department with severe dyspnea at rest. Each had sinus tachycardia with tachypnea and an echocardiogram that showed severe systolic dysfunction consistent with heart failure. Additional evaluation in the hospital revealed cardiomyopathy with no other etiology other than the meth use.

Conclusion

There are several reports that show an increase in frequency of meth use, suggesting that cardiomyopathy and acute heart failure may be a new medical concern.

A comparison of echocardiographic findings in young adults with cardiomyopathy: with and without a history of methamphetamine abuse

BACKGROUND

Methamphetamine is currently the most widespread illegal stimulant abused in the United States. No previous reports comparing echocardiographic findings of cardiomyopathy with and without a history of methamphetamine abuse are available.

METHODS

We performed a single institution retrospective review of medical records and analyses of echocardiographic findings in patients < or = 45 years of age hospitalized between 2001 and 2004 who were discharged with a diagnosis of cardiomyopathy or heart failure. After exclusion of patients with coronary artery disease or severe cardiac valvular disease, the remaining patients were divided into 2 groups based on their abuse or non abuse of methamphetamine, as determined by the documented history in the medical records or urine toxicology testing.

RESULTS

Among a total of 59 patients, 28 (47%) had a history of methamphetamine abuse or positive urine toxicology. Both methamphetamine abusers and non-abusers were predominately male (64.3% vs 64.5%, P = .99), and had a high prevalence of obesity (55.6% vs 73.3%, P = .16). Bivariate analysis revealed significant differences between the methamphetamine abusers and non-abusers in left atrium volume (119.7 +/- 55.4 ml vs 85.8 +/- 33.5 ml, P = .008), left ventricular end-diastolic volume (201.9 +/- 71.4 ml vs 156.6 +/- 63.1 ml, P = .01), left ventricular end-systolic volume (136.0 +/- 53.7 ml vs 92.3 +/- 55.8 ml, P = .004), right ventricular dimension (26.3 +/- 6.0 mm vs 21.3 +/- 6.0 mm, P = .007), and quantified left ventricular ejection fraction (32.9% +/- 11.3% vs 44.6% +/- 17.8%, P = .004).

CONCLUSIONS

We found a high prevalence of methamphetamine abuse in our study population. Methamphetamine abusers had echocardiographic findings of more severe dilated cardiomyopathy compared with non-abusers.

Recovery of methamphetamine associated cardiomyopathy predicted by late gadolinium enhanced cardiovascular magnetic resonance

Methamphetamine is known to cause a cardiomyopathy which may be reversible with appropriate medical therapy and cessation of use. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) has been shown to identify fibrosis in ischemic and non-ischemic cardiomyopathies. We present a case of severe methamphetamine-associated cardiomyopathy in which cardiac function recovered after 6 months. Evaluation by CMR using late gadolinium enhancement was notable for an absence of enhancement, suggesting an absence of irreversible myocyte injury and a good prognosis. CMR may be useful to predict recovery in toxin-associated non-ischemic cardiomyopathies.

Acute methamphetamine exposure inhibits cardiac contractile function

Methamphetamine, a commonly seen substance of abuse, has been reported to exert detrimental effect on bodily function including the cardiovascular system although its mechanism of action is poorly understood. This study was designed to examine the direct impact of methamphetamine on isolated whole heart and single cardiomyocyte contractile function. Murine hearts and isolated cardiomyocytes from adult FVB mice were exposed to various concentrations of methamphetamine for 30min prior to the assessment of mechanical function using a Langendroff apparatus and an IonOptix Myocam system, respectively. Cardiac contractile properties analyzed included maximal velocity of left ventricular pressure development and decline (+/-dP/dt), peak shortening amplitude (PS), maximal velocity of shortening/relengthening (+/-dLdt), time-to-PS (TPS), time-to-90% relengthening (TR(90)), resting and electrically stimulated increase of intracellular Ca(2+) as well as intracellular Ca(2+) decay. Our results revealed that acute methamphetamine exposure depressed +/-dP/dt, PS and rise of intracellular Ca(2+) without affecting +/-dLdt, TPS, TR(90), resting intracellular Ca(2+) and intracellular Ca(2+) decay. Furthermore, methamphetamine nullified the adrenergic agonist norepinephrine-elicited positive cardiomyocyte contractile response, including elevated PS, +/-dLdt and shortened TR(90) without affecting TPS. Western blot analysis showed unchanged expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) and phospholamban, associated with upregulated Na(+)-Ca(2+) exchanger levels following acute methamphetamine exposure. In addition, methamphetamine promoted overt cardiomyocyte protein damage evaluated by carbonyl formation. Taken together, these results demonstrate direct cardiac depressant effect of methamphetamine in myocardium and isolated cardiomyocytes, possibly associated with protein damage and dampened adrenergic response.

Methamphetamine-related fatalities in Australia: demographics, circumstances, toxicology and major organ pathology

AIM

To examine the demographic characteristics, circumstances of death, toxicological results and major organ pathology of methamphetamine-related deaths in Australia.

DESIGN

Retrospective review of coronial files.

SETTING

Australia.

METHODS

Cases in which methamphetamine was listed as a cause of death were identified from the National Coronial Information System (NCIS).

FINDINGS

A total of 371 cases were identified. The mean age of decedents was 32.7 years; 77% were male and 35% were employed. Route of administration was predominantly by injection (89%). Drugs other than methamphetamine were detected in 89% of cases, most commonly benzodiazepines (41%) and morphine (36%). The median blood methamphetamine concentration was 0.2 mg/l (range 0.02-15.0 mg/l). Deaths were overwhelmingly accidental, with 14% determined to be suicides, and occurred in a private home (71%). Cardiovascular pathology, typically coronary artery atherosclerosis, was detected in 54% of decedents. Cerebrovascular pathology, most commonly cerebral haemorrhage and hypoxia, was present in 20% of cases.

CONCLUSIONS

Methamphetamine has contributed to a substantial number of deaths in Australia. Users need to be informed of the potential harms of methamphetamine use, particularly those associated with the cardiotoxicity of methamphetamine and the use of methamphetamine in conjunction with other drugs.

Spectrophotometric study of the charge-transfer and ion-pair complexation of methamphetamine with some acceptors

The charge-transfer (CT) complexes of methamphetamine (MPA) as a n-donor with several acceptors including bromocresolgreen (BCG), bromocresolpurple (BCP), chlorophenolred (CPR), picric acid (PIC), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) have been studied spectrophotometrically in chloroform solutions in order to obtain some information about their stoichiometry and stability of complexation. The oscillator strengths, transition dipole moments and resonance energy of the complex in the ground state for all complexes have been calculated. Vertical ionization potential of MPA and electron affinity of acceptors were determined by ab initio calculation. The acceptors were also used to utilize a simple and sensitive extraction-spectrophotometric method for the determination of MPA. The method is based on the formation of 1:1 ion-pair association complexes of MPA with BCG, BCP and PIC in chloroform medium. Beer's plots were obeyed in a general concentration range of 0.24-22 microg ml(-1) for the investigated drug with different acceptors. The proposed methods were applied successfully for the determination of MAP in pure and abuse drug with good accuracy and precision.

Methamphetamine and cardiovascular pathology: a review of the evidence

AIMS

To examine the literature pertaining to the cardiovascular effects of methamphetamine and discuss the implications for methamphetamine users.

METHODS

Relevant literature was identified through comprehensive MEDLINE and EMBASE searches.

FINDINGS AND CONCLUSIONS

There is sufficient clinical and experimental evidence to suggest that methamphetamine can have adverse and potentially fatal effects on the cardiovascular system. The existing literature suggests that: (1) methamphetamine users are at elevated risk of cardiac pathology; (2) risk is not likely to be limited to the duration of their methamphetamine use, because of the chronic pathology associated with methamphetamine use; (3) the risk of cardiac pathology is greatest among chronic methamphetamine users; (4) pre-existing cardiac pathology, due to methamphetamine use or other factors, increases the risk of an acute cardiac event; and (5) methamphetamine use is likely to exacerbate the risk of cardiac pathology from other causes, and may therefore lead to premature mortality.

Electrocardiographic abnormalities in methamphetamine abusers

AIMS

Although many adverse cardiovascular outcomes are mentioned in conjunction with methamphetamine use, a causal relationship between methamphetamine use and arrhythmia or cardiomyopathy has not been demonstrated in man. Clinical experience with methamphetamine users suggested a higher incidence of electrocardiographic abnormalities. This study seeks to quantify that incidence, among subjects enrolled in a study of adults with methamphetamine dependence.

METHODS

Electrocardiograms obtained during screening in a previous clinical trial were examined. The study population (n = 158) of adults with methamphetamine dependence [Diagnostic and Statistical Manual version IV (DSM IV-TR)] was drawn from five sites across the United States, recruited in the interval 2002-03.

RESULTS

A significant variance from the normal population was noted in the electrocardiograms of the study cohort. Among the abnormalities was a prolongation of the QTc beyond 440 ms in 27.2% of the group. QTc prolongation to this extent poses a particular risk for ventricular arrhythmias, most notably torsades de pointes.

CONCLUSIONS

We believe that this is the first demonstration of clinically significant QTc prolongation in a methamphetamine-using population, and that this has implications for the types of arrhythmias for which this population is at risk. It may further provide a marker for risk of cardiomyopathy. The fact of electrocardiographic changes with potential cardiac risks may be useful in a motivational interviewing approach, in challenging the methamphetamine user's basis for continuing use.

The association of methamphetamine use and cardiomyopathy in young patients

PURPOSE

Methamphetamine is the most widespread illegally used stimulant in the United States. Previously published case reports and series suggest a potential association between methamphetamine exposure and cardiomyopathy. The objective of this study is to demonstrate an association between methamphetamine use and cardiomyopathy.

SUBJECT AND METHODS

Case-control study based on chart review of discharges from a tertiary care medical center from January 2001 to June 2004. Patients were < or =45 years old. Cases included patients with a discharge diagnosis of either cardiomyopathy or heart failure. Controls included hospitalized patients who had an echocardiographic assessment of left ventricular function with ejection fraction > or =55% and no wall motion abnormalities.

RESULTS

One hundred and seven cases and 114 controls were identified. Both groups had similar gender distribution, length of hospital stay, rates of health insurance, prevalence of coronary artery disease, diabetes mellitus, hypertension, cigarette smoking, alcohol abuse, and marijuana and cocaine use. Cases were older than controls (mean age: 38 vs 35 years; P=.008), had higher body mass index (BMI) (mean BMI: 37 vs 30 kg/m2; P<.001), and higher prevalence of renal failure (13% vs 4.4%; P=.03). Methamphetamine users had a 3.7-fold increased odds ratio [95% confidence interval, 1.8-7.8] for cardiomyopathy, adjusting for age, body mass index, and renal failure.

CONCLUSIONS

Methamphetamine use was associated with cardiomyopathy in young patients.

A case of carbamazepine overdose with focal myocarditis

An autopsy case of carbamazepine overdose with focal myocarditis is reported. The decedent was a 33-year-old female with a history of schizophrenia and bipolar disorder, who reportedly took 5-day dose of prescribed medications at around midnight. Although she stayed home following the direction of the physician, she was pronounced dead 8h after the intake. At autopsy she was obese, and her face was slightly swollen. The 420 g heart was free of coronary atherosclerosis, and the myocardium had no obvious scars. Both the left and right lungs were markedly congested and edematous. Strong congestion was also noted in the brain and visceral organs. Microscopic examination disclosed focal infiltration of inflammatory cells, most of which were lymphocytes, into the myocardium. In the toxicological analyses, carbamazepine concentration in the blood was 9.9 microg/ml, and other medications were below the toxic levels. It was considered that under the compromised cardiac function due to myocarditis presumably induced by some prescribed medications, and obesity, the carbamazepine overdose deteriorated her condition by triggering critical arrhythmia or congestive heart failure.

Methamphetamine in hair and interpretation of forensic findings in a fatal case

Hair analysis for drugs has been developing and is considered a significant tool for distinguishing between recent and long-term drug abuse in forensic and clinical toxicology. Chronic consumption of drugs can gradually induce certain harmful effects on the human organism and can exacerbate some pre-existing diseases. Analysis for drugs in blood or urine in isolation does not provide sufficient information about the history of drug-use by a person and their results cannot be correlated directly with the toxic effects displayed. The chronic abuse of methamphetamine is known to be associated with cardiovascular diseases. During or after autopsy certain types of morphologic alterations are found in the hearts of stimulant addicts. The rapid increase in blood pressure after an intravenous methamphetamine dose can be risky for addicts with arteriosclerosis. However, the anamnestic data about a deceased person may not always be available to explain the pathological findings and to classify the cause of death correctly. The aim of this study was to demonstrate the value of hair analysis for drugs in the context of explaining pathological cardiovascular alterations observed during the autopsy in a case where methamphetamine consumption was involved. In this case, only methamphetamine and metabolites were detected with traces of ephedrine. Ephedrine is the precursor chemical in the illicit synthesis of methamphetamine (known in the Czech Republic as "Pervitin"). The femoral blood level of methamphetamine was 1500 ng/ml. It was documented by a witness that the 31-year-old man died within 1h after an intravenous injection of the drug. The cause of death was established as cerebral edema due to cerebellar bleeding shortly after an intravenous dose of methamphetamine. Findings of methamphetamine in the first three 2-cm hair segments (numbered from the roots) were nearly equal (132+/-9 ng/mg). In the fourth 2-cm segment, it was approximately one-half of previous values. In the remaining, distal 7-cm hair segment sample, the value of methamphetamine was higher and comparable to the third segment. These results provide clear evidence that the man had been a chronic methamphetamine abuser for more than 8 months. This information can help to explain the pathology, the consequence of which could be the bleeding into the cerebellum after the last single methamphetamine dose.

Maternal methamphetamine administration during pregnancy influences on fetal rat heart development

Methamphetamine (MAP) is one of the most abused drugs in Japan. The rate of MAP abuse by young women has recently reached more than 50 percent in adolescents. A major health concern is that these women will continue to use MAP during pregnancy. The purpose of this study was to investigate whether MAP administered to the mother during pregnancy would change the expression of alpha- and beta- myosin heavy chain (MHC) mRNA in rat neonatal hearts, as detected by quantitative RT-PCR. In addition, morphological changes in the rat neonatal ventricles were examined. Pregnant rats were injected intraperitoneally with MAP (1 mg/kg/day) starting at day 0 of gestation and ending at day 21. There was a significant increase in alpha-MHC mRNA expression in the neonatal ventricular muscle in the experimental group compared with the control at postnatal day (P) 0 and 5. alpha-MHC mRNA expression in both groups was similar after P9. beta-MHC mRNA expression was similar in both groups at P0. Postnatal beta-MHC mRNA expression decreased rapidly, but significant alteration was not detected. Neonatal rats at P0 exhibited some cardiac changes, including hypertrophy, degeneration, and disarrangement of myofibers, but these lesions disappeared by P14. We conclude that chronic maternal administration of MAP changes the alpha- and beta-MHC mRNA expression pattern in fetal and neonatal hearts, correlating with abnormal development, plasma level of hormones, and myocardial damage. At the same time, it is indicated that neonatal cardiomyocytes have reversibility.

Heart disease, methamphetamine and AIDS

Methamphetamine (MA) not only affects the nervous system but also has cardiac toxicity and immunosuppressive properties. This manuscript will provide support that there is a relationship between MA use and heart disease as well as immune dysfunction. The cardiovascular manifestations of acute MA use include tachycardia, atrioventricular arrhythmias, myocardial ischemia, myocardial ischemia and hypertension, resulting in cardiac lesions. Chronic use of MA causes cardiomyopathy including cellular infiltration, myocardial hypertrophy, myocardium rupture and fibrosis. The increased catecholamine levels are responsible for the cardiac lesions induced by MA. The additional problem with MA use is its potential to disrupt the immune system function leading to suppression of mitogen-stimulated lymphocyte, a reduction in circulating lymphocyte numbers and alternation T-lymphocyte cytokine secretion as well as B cell proinflammatory cytokine secretion. Concomitant MA use and Human Immunodeficiency Virus (HIV) infection not only enhances immunosuppression associated with HIV but also increases the heart disease occurrence with a coincidentally complication of AIDS or AIDS medications.

Crystal Methamphetamine‐Associated Cardiomyopathy: Tip of the Iceberg?

BACKGROUND

Crystal methamphetamine has become a drug of widespread use. Previous reports describe myocardial infarction, pulmonary edema, and aortic dissection related to methamphetamine use. Cardiomyopathy due to methamphetamine exposure has been rarely described.

METHODS

We identified 1640 patients admitted in a 4-yr period with a primary or secondary diagnosis of cardiomyopathy. We excluded patients with known cause of cardiomyopathy other than substance abuse. We found 120 patients had a diagnosis of substance abuse, including 21 patients with methamphetamine use. We retrospectively reviewed the medical records of these 21 crystal methamphetamine users.

RESULTS

Nineteen (84%) underwent echocardiography with consistent findings of dilated cardiomyopathy and global ventricular dysfunction. Of five who had a nuclear myocardial perfusion study, none had evidence of ischemia or infarct. Of six who underwent cardiac catheterization, only one had evidence of coronary stenosis.

CONCLUSION

Methamphetamine use appears to produce cardiomyopathy in some users. The pathogenesis is probably similar to that of cocaine and catecholamine-induced cardiomyopathy. Cellular, animal, and clinical data support the link between methamphetamine exposure and myocardial pathology.

Effects of chronic methamphetamine exposure on heart function in uninfected and retrovirus-infected mice

Methamphetamine (MA) increases catecholamine levels, which have detrimental effects on heart function through vasoconstriction, myocardial hypertrophy, and fibrosis. Murine retrovirus infection induces dilated cardiomyopathy (DCM). The present study investigated the cardiovascular effects of chronic MA treatment on uninfected and retrovirus-infected mice. C57BL/6 mice were studied after 12 weeks treatment. The four study groups were (group I) uninfected, MA placebo; (group II) infected, MA placebo; (group III) uninfected, MA treatment; and (group IV) infected and MA treatment. MA injections were given i.p. once a day for 5 days/week with a increasing dose from 15 mg/kg to 40 mg/kg. Left ventricular mechanics were measured in situ a using Millar conductance catheter system for pressure-volume loop analysis. Cardiac pathology was determined with histological analysis. In the uninfected mice, the load independent contractile parameters, pre-load recruitable stroke work (PRSW) and dP/dt(max) vs. Ved, significantly decreased by 32% and 35% in MA treated mice when compared to the saline injected mice. In retrovirus-infected mice, although there were no significant difference in Ees, PRSW, and dP/dt(max) vs. Ved due to MA treatment, they were increased 45%, 15% and 42% respectively when compared to saline treated mice. No further lowered heart function during murine AIDS may be due to the counteraction of the retroviral DCM and the MA induced myocardial fibrosis and hypertrophy (thickening of the ventricular walls). This is supported by increases in the End-diastolic volume (Ved, 38%) and End-systolic volume (Ves, 84%) in the retrovirus-infected saline injected mice, the decreases of 33% and 17% in the uninfected MA-treated mice, but no significant changes in the retrovirus-infected MA treated mice when compared to uninfected saline injected mice. These data suggest that MA induced myocardial cellular changes compensate for retrovirus induced DCM.