Amphetamine increases vascular permeability by modulating endothelial actin cytoskeleton and NO synthase via PAR-1 and VEGF-R

Abuse of amphetamine-type stimulants is linked to cardiovascular adverse effects like arrhythmias, accelerated atherosclerosis, acute coronary syndromes and sudden cardiac death. Excessive catecholamine release following amphetamine use causes vasoconstriction and vasospasms, over time leading to hypertension, endothelial dysfunction or even cardiotoxicity. However, immediate vascular pathomechanisms related to amphetamine exposure, especially endothelial function, remain incompletely understood and were analyzed in this study. Pharmaco-pathological effects of acute d-amphetamine-sulfate (DAM) were investigated ex vivo using contraction-force measurements of rat carotid artery rings and in vitro using label-free, real-time electrochemical impedance spectroscopy (EIS) on endothelial and smooth muscle cells. Specific receptor and target blocking was used to identify molecular targets and to characterize intracellular signaling. DAM induced vasodilation represented by 29.3±2.5% decrease in vascular tone (p<0.001) involving vascular endothelial growth factor receptor (VEGF-R) and protease activated receptor 1 (PAR-1). EIS revealed that DAM induces endothelial barrier disruption (-75.9±1.1% of initial cellular impedance, p<0.001) also involving VEGF-R and PAR-1. Further, in response to DAM, Rho-associated protein kinase (ROCK) mediated reversible contraction of actin cytoskeleton resulting in endothelial barrier disruption. Dephosphorylation of Serine1177 (-50.8±3.7%, p<0.001) and Threonine495 (-44.8±6.5%, p=0.0103) of the endothelial NO synthase (eNOS) were also observed. Blocking of VEGF-R and PAR-1 restored baseline eNOS Threonine495 phosphorylation. DAM induced vasodilation, enhanced vascular permeability and actin cytoskeleton contraction and induced eNOS hypophosphorylation involving VEGF-R, PAR-1 and ROCK. These results may contribute to a better understanding of severe adverse cardiovascular effects in amphetamine abuse.

Methamphetamine spasm in the large caliber arteries-the severity is likely underestimated

This report describes two cases of rarely reported, severe large arterial vascular spasms seen on computed tomography images after methamphetamine abuse. Although the effects of methamphetamine on the central nervous system and smaller arteries are relatively well known, its effects on large caliber arteries are rarely discussed. We present two cases of severe large arterial multisegmented vasospasm, captured on contrast-enhanced computed tomography, several hours after methamphetamine abuse. One of the patients was discharged without apparent tissue loss or organ failure. The other developed severe heart failure, liver failure, and toe gangrene. The publication of the de-identified images has been approved by the VA Central California Health Care System's Research and Development Committee and Privacy Officer. Vascular surgeons and, perhaps, acute care physicians, who are usually aware of small arterial vasospastic conditions, should also be aware of this methamphetamine-induced large arterial finding, which can be quite dramatic in appearance on imaging.

Cardiovascular Considerations for Stimulant Class Medications

The cardiovascular (CV) impact of stimulants has been examined for decades, with investigations ranging from small sample targeted studies of heart rate (HR) and blood pressure (BP), to large scale epidemiologic investigations. The preponderance of evidence is reassuring, albeit generally based on healthy samples using variable methodology, excluding those at theoretic high risk (eg, comorbid cardiac illness). Screening for theoretically vulnerable patients are recommended, as well as monitoring for CV symptoms and BP/HR, with shared inquiry/further evaluation if concerned. Future investigations to support the identification of risk are needed, while attention to stimulant-associated CV risk is an opportunity for clinicians to engage in general CV risk identification and intervention.

Digital Gangrene: An Unusual Manifestation of Non-Hodgkin Lymphoma

Background

Non-Hodgkin lymphomas (NHLs) comprise a group of haematologic malignancies with different histologic subtypes. The clinical picture varies from indolent to aggressive presentation and nodal (lymphadenopathy) to extranodal (central nervous system, gastrointestinal, cutaneous plaque, or ulcer) involvement. Digital gangrene is seldom reported. Here, we describe a patient with pain and blackening of all fingers and toes as presenting symptoms of NHL. Case Presentation. A 32-year-old male weaver had been smoking three to five cannabis-containing cigarettes daily for about ten years and methamphetamine four to five tablets daily for five years. He had no history of Raynaud's phenomenon, fever, cough, weight loss, skin rash, joint pain, and atherogenic or thrombogenic risk factors. We found normal blood pressure and absent peripheral pulses in arms and legs, dry gangrene of all fingers and toes, generalized lymphadenopathy, and hepatomegaly with ascites. The chest X-ray was normal, as were blood sugar, lipid profile, and hepatic and renal function. Rheumatoid factor, antinuclear and antiphospholipid antibodies, C-ANCA and P-ANCA, hepatitis B and C, and HIV were negative. CT abdomen revealed hepatosplenomegaly with multiple intra-abdominal lymphadenopathies. The peripheral angiogram showed 90-99% stenosis of radial and dorsalis pedis arteries with normal proximal vessels. Diagnosis of non-Hodgkin lymphoma was confirmed by histopathology of cervical lymph node (diffuse type), immunohistochemically subtyped as peripheral T cell lymphoma (not otherwise specified). The digital ischemia worsened despite cessation of cannabis and methamphetamine and starting CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) treatment, making amputation necessary.

Conclusion

We present, to our knowledge, the first report of peripheral T cell lymphoma, NOS presenting with gangrene in all digits complicated by methamphetamine and cannabis abuse. This uncommon vascular manifestation of non-Hodgkin lymphoma may cause a diagnostic dilemma and delayed initiation of treatment.

Association between central nervous system stimulants used to treat attention deficit hyperactivity disorder (ADHD) and Raynaud's phenomenon: A scoping review

The association between central nervous (CNS) stimulants used to treat attention deficit hyperactivity disorder (ADHD) and Raynaud's phenomenon (RP) has received little attention to date. Our aim was to map the existing literature on aetiopathogenesis, clinical presentation and management of peripheral vasculopathy, with a focus on RP, secondary to drug therapy for ADHD. We searched the PubMed® database (01/11/1951 to 01/08/2020) and included articles written in English, which focussed on CNS stimulants used to treat ADHD and RP. The search identified 150 articles 9 of which were eligible for inclusion (70 patients). The majority of studies (n = 6) related to children or adolescents; however, adult cases were also identified. Peripheral vascular manifestations included attacks of RP (new and worsening) and cold sensitivity (acrocyanosis and perniosis). Irreversible ischaemic complications including digital autoamputation and lower limb critical digital ischaemia have also been reported. The implicated causative CNS stimulants were Methylphenidate (n = 5), Dextroamphetamine (n = 4), Atomoxetine (n = 2), and Lisdexamphetamine (n = 2). Complete resolution of RP symptoms was observed in half (n = 5) of studies upon drug cessation. Other therapeutic strategies have included dose reduction and switching to an alternative drug therapy. A potential autoimmune association has also been postulated including drug-induced autoimmunity and new cases of systemic sclerosis which have been potentially attributed to treatment. Future research is required to understand the association between CNS stimulant drug therapies for ADHD and peripheral vascular manifestations, including RP.

Prinzmetal-Like Acute Limb Ischemia

Vasospasm-induced acute limb ischemia (ALI), also known as vasospastic limb ischemia (VLI), is a rare, underreported vascular event. Unlike thrombotic and embolic occlusive etiologies, which often warrant revascularization, vasospasm is a transient phenomenon that may be successfully managed conservatively without surgical intervention. Thus, prompt recognition and accurate diagnosis of VLI is imperative to avoid unnecessary surgical or endovascular procedures. This diagnosis, however, can pose as a challenge for clinicians, as it can present with clinical signs and symptoms near-identical to the presentation of thrombotic-induced ALI. In this report, we present a patient that experienced 2 vasospasm-induced ischemic events; the patient developed Rutherford IIb acute limb-threatening ischemia following cardiac catheterization for myocardial infarction. Computer tomography angiography findings of her right leg revealed acute occlusion suggesting the need for immediate operative intervention for limb salvage. However, due to her critical state, she instead was managed with medical treatments. Despite no intervention, the patient had full resolution of her right leg symptoms. We present this case to highlight the unusual multifocality of vasospastic events and to increase awareness of the diagnostic challenges associated with VLI.

Premature atherosclerotic peripheral artery disease: An underrecognized and undertreated disorder with a rising global prevalence

Premature atherosclerotic peripheral artery disease (PAD) of the lower extremities is characterized by disease diagnosis before the age of 50 years. The global prevalence of premature PAD has increased, and the disease is often underdiagnosed given heterogenous patient symptoms. Traditional cardiovascular risk factors like smoking, diabetes, hypertension, and hyperlipidemia as well as non-traditional risk factors like elevated lipoprotein(a), family history of PAD, hypercoagulability, and systemic inflammation are associated with premature PAD. Patients with premature PAD tend to have an aggressive vascular disease process, a high burden of cardiovascular risk factors, and other concomitant atherosclerotic vascular diseases like coronary artery disease. Prevention of cardiovascular events, improvement of symptoms and functional status, and prevention of adverse limb events are the main goals of patient management. In this review, we discuss the epidemiology, risk factors, clinical evaluation, and management of patients with premature PAD.