Endothelium-dependent vasorelaxation is impaired in cocaine arteriopathy

Endovascular Management of Acute Lower Limb Ischemia Linked to Cocaine Abuse: A Case Report

Cocaine abuse is a public health concern with well-documented cardiovascular complications. However, acute limb ischemia remains a rare and underreported consequence. We present a case of a 36-year-old man with acute right lower limb ischemia following heavy cocaine use, successfully managed with systemic heparin and intra-arterial nitroglycerin. The case highlights considering cocaine as a potential cause of acute limb ischemia and the efficacy of endovascular therapy. Further case reports with this diagnosis and their management are crucial for establishing the best strategies and improving outcomes in these scenarios.

Endovascular Treatment of Acute Lower Limb Ischemia Associated with Cocaine Use: A Scoping Review

The endovascular treatment of acute lower limb ischemia associated with cocaine use is an underexplored topic. This scoping review aims to map existing information and point out potential knowledge gaps for future research. We searched databases with a strategy of terms and keywords (Cocaine, Acute, Lower Limb, and Ischemia) for articles related to acute ischemia in the lower limbs and cocaine use. We established eligibility and exclusion criteria and searched without restrictions on language or date of publication. We obtained five case reports published between 2004 and 2015. Most of the patients were men with an average age of 38 years. Treatments were heterogeneous. Most patients showed improvement after surgical thrombectomy. The sample size and variety of interventions limit the generalizability of the results, so it is necessary to do more studies with robust methodologies to standardize treatments and improve the understanding of the condition.

Cocaine-Induced Ascending Aortic Thrombus

Aortic thrombosis without coexisting atherosclerosis is uncommon. Sometimes, aneurysms or dissections can predispose to thrombus in the abdominal or thoracic aorta. However, ascending aortic thrombus in a non-aneurysmal, non-atherosclerotic aorta is a rare occurrence. Although arterial thrombosis has been linked with its use, cocaine-associated thrombus of the ascending aorta has been rarely described. We report a young man with regular use of cocaine presenting with constant, burning, left-sided chest pain. He was found to have a large thrombus in a structurally normal ascending aorta. Medical management with therapeutic anticoagulation was started. Despite an interruption of anticoagulation treatment for two months due to non-compliance, the man survived. This unique case highlights the importance of various vascular complications associated with cocaine use, their early recognition, and their treatment.

MicroRNA-423-5p Mediates Cocaine-Induced Smooth Muscle Cell Contraction by Targeting Cacna2d2

Cocaine abuse increases the risk of atherosclerotic cardiovascular disease (CVD) and causes acute coronary syndromes (ACS) and hypertension (HTN). Significant research has explored the role of the sympathetic nervous system mediating the cocaine effects on the cardiovascular (CV) system. However, the response of the sympathetic nervous system alone is insufficient to completely account for the CV consequences seen in cocaine users. In this study, we examined the role of microRNAs (miRNAs) in mediating the effect of cocaine on the CV system. MiRNAs regulate many important biological processes and have been associated with both response to cocaine and CV disease development. Multiple miRNAs have altered expression in the CV system (CVS) upon cocaine exposure. To understand the molecular mechanisms underlying the cocaine response in the CV system, we studied the role of miRNA-423-5p and its target Cacna2d2 in the regulation of intracellular calcium concentration and SMC contractility, a critical factor in the modulation of blood pressure (BP). We used in vivo models to evaluate BP and aortic stiffness. In vitro, cocaine treatment decreased miR-423-5p expression and increased Cacna2d2 expression, which led to elevated intracellular calcium concentrations and increased SMC contractility. Overexpression of miR-423-5p, silencing of its target Cacna2d2, and treatment with a calcium channel blocker reversed the elevated SMC contractility caused by cocaine. In contrast, suppression of miR-423-5p increased the intracellular calcium concentration and SMC contractibility. In vivo, smooth muscle-specific overexpression of miR-423-5p ameliorated the increase in BP and aortic stiffness associated with cocaine use. Thus, miR-423-5p regulates SMC contraction by modulating Cacna2d2 expression increasing intracellular calcium concentrations. Modulation of the miR-423-5p-Cacna2d2-Calcium transport pathway may represent a novel therapeutic strategy to improve cocaine-induced HTN and aortic stiffness.

Early Onset Cardiovascular Disease from Cocaine, Amphetamines, Alcohol, and Marijuana

Cardiovascular disease (CVD), a disease typically associated with aging and the definitive leading cause of death worldwide, now threatens the young and middle-aged populations. Recreational abuse of alcohol, marijuana, cocaine and amphetamine-type stimulants has been an escalating public health problem for decades, but now use of these substances has become a significant contributor to early onset CVD. While this remains a global phenomenon, the epicenter of substance abuse is rooted in North America where it has been exacerbated by the COVID-19 pandemic. For the first time in history, the United States (US) crossed 100,000 overdose-related deaths in a calendar year. Sadly, Canada's recreational drug abuse problem closely mirrors that of the US. This is indicative of the larger public health crisis unfolding, as we now know that these substances are cardiotoxic and are contributing to the rising levels of premature chronic CVD, including hypertension, arrhythmias, heart failure, stroke, myocardial infarction, arterial dissection, sudden cardiac death and early mortality.

Contribution of Risk Factors to the Development of Coronary Atherosclerosis as Confirmed via Coronary CT Angiography: A Longitudinal Radiomics-based Study

Background Various cardiovascular risk factors are thought to modify atherosclerosis in a similar fashion (ie, by increasing the magnitude of coronary artery disease [CAD]). However, coronary CT angiography allows precision phenotyping of plaque characteristics through use of radiomics. Purpose To assess whether different cardiovascular risk factors have distinctive contributions to the changes in plaque morphologic features over time. Materials and Methods Individuals with or without HIV infection and cocaine use and without cardiovascular symptoms underwent coronary CT angiography between May 2004 and August 2015. In the current HIPAA-compliant study, the effects of cocaine use, HIV infection, and atherosclerotic cardiovascular disease (ASCVD) risk on the temporal changes (mean ± standard deviation, 4.0 years ± 2.3 between CT angiographic examinations) in CAD structure were analyzed by using radiomic analysis. The changes in radiomic features were analyzed by using linear mixed models, with correction for factors that may change plaque structure: high-sensitivity C-reactive protein level, statin use, positive family history of CAD, and total plaque volume to account for any potential intrinsic correlation between volume and morphologic features. Clusters among significant radiomic features were identified by using hierarchical clustering. Bonferroni-corrected P values less than .00004 (.05 divided by 1276) were considered to indicate significant differences. Results Of 1429 participants, 300 with CAD confirmed at coronary CT angiography were randomly selected (mean age, 48 years ± 7; 210 men, 226 people infected with HIV, 174 people who use cocaine) and 1276 radiomic features were quantified for each plaque. Cocaine use was significantly associated with 23.7% (303 of 1276) of the radiomic features, HIV infection was significantly associated with 1.3% (17 of 1276), and elevated ASCVD risk was significantly associated with 8.2% (104 of 1276) (P < .00004 for all). Parameters associated with elevated ASCVD risk or cocaine use and HIV infection did not overlap. There were 13 clusters among the 409 parameters, eight of which were affected only by cocaine use and three of which were affected only by ASCVD risk. Conclusion Radiomics-based precision phenotyping indicated that conventional risk factors, cocaine use, and HIV infection each had different effects on CT angiographic morphologic changes in coronary atherosclerosis over 4 years. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Schoepf and Emrich in this issue.

Impact of polysubstance use on high-sensitivity cardiac troponin I over time in homeless and unstably housed women

INTRODUCTION

The use of controlled substances like cocaine increases the risk of cardiovascular disease (CVD) and myocardial infarction (MI). However, outside of alcohol and tobacco, substance use is not included in CVD risk assessment tools. We identified the effects of using multiple substances (nicotine/cotinine, cannabis, alcohol, cocaine, methamphetamine, heroin and other opioids) on cardiac injury measured by high-sensitivity troponin (hsTnI) in homeless and unstably housed women.

METHODS

We recruited 245 homeless and unstably housed women from shelters, free meal programs and street encampments. Participants completed six monthly study visits. Adjusting for traditional CVD risk factors, we examined longitudinal associations between substance use and hsTnI.

RESULTS

Median participant age was 53 years and 74 % were ethnic minority women. At baseline, 76 % of participants had hypertension, 31 % were HIV-positive, 8% had a history of a prior MI and 12 % of prior stroke. The most commonly used substances were cotinine/nicotine (80 %), cannabis (68 %) and cocaine (66 %). HsTnI exceeding the 99th percentile (14.7 ng/L) - a level high enough to signal possible MI - was observed in 14 participants during >1 study visit (6%). In adjusted analysis, cocaethylene and fentanyl were significantly associated with higher hsTnI levels.

CONCLUSIONS

Fentanyl use and the co-use of cocaine and alcohol are associated with myocardial injury, suggesting that the use of these substances may act as long-term cardiac insults. Whether risk counseling on these specific substances and/or including their use in CVD risk stratification would improve CVD outcomes in populations where substance use is high merits further investigation.

Abdominal Imaging Manifestations of Recreational Drug Use

Recreational drug use is a burgeoning health issue worldwide, with a variety of presenting symptoms and complications. These complications can be secondary to the toxic effects of the drug itself, drug impurities, and nonsterile injection. The abdominal radiologist is likely to encounter patients who use drugs recreationally and may be responsible for recognizing and reporting these acute conditions, which in some cases can be life threatening. Because these patients often present with an altered mental state and may deny or withhold information on drug use, the underlying cause may be difficult to determine. The most commonly used drugs worldwide include cocaine, cannabinoids, opioids, and amphetamines and their derivatives. Complications of use of these drugs that can be seen at abdominopelvic CT can involve multiple organ systems, including the soft tissue and gastrointestinal, genitourinary, vascular, and musculoskeletal systems. A diverse range of abdominal complications associated with these drugs can be seen at imaging, including disseminated infections, gastrointestinal ischemia, and visceral infarction. Radiologists should be familiar with the imaging findings of these complications to accurately diagnose these entities and help guide workup and patient treatment. ^©RSNA, 2020.

Substance Use Disorder in the COVID-19 Pandemic: A Systematic Review of Vulnerabilities and Complications

As the world endures the coronavirus disease 2019 (COVID-19) pandemic, the conditions of 35 million vulnerable individuals struggling with substance use disorders (SUDs) worldwide have not received sufficient attention for their special health and medical needs. Many of these individuals are complicated by underlying health conditions, such as cardiovascular and lung diseases and undermined immune systems. During the pandemic, access to the healthcare systems and support groups is greatly diminished. Current research on COVID-19 has not addressed the unique challenges facing individuals with SUDs, including the heightened vulnerability and susceptibility to the disease. In this systematic review, we will discuss the pathogenesis and pathology of COVID-19, and highlight potential risk factors and complications to these individuals. We will also provide insights and considerations for COVID-19 treatment and prevention in patients with SUDs.

Hypoperfusion of the deep capillary plexus associated with acute on chronic cocaine use

PURPOSE

To illustrate a case of decreased perfusion in the deep capillary plexus seen on ocular coherence tomography angiography in a patient with acute on chronic cocaine use.

OBSERVATIONS

A 69-year-old male who presented with a sudden loss of vision in his right eye following recent use of cocaine. Ocular coherence tomography of the right eye revealed hyperreflectivity within layers of the retina and ocular coherence tomography angiography showed decreased vascular density and flow in the deep capillary plexus.

CONCLUSIONS AND IMPORTANCE

Cocaine use has been associated with systemic and cardiac effects, as well as ocular sequelae. It has been hypothesized to have a role in the pathogenesis of acute macular neuroretinopathy. Here we present the first case of ocular coherence tomography angiography findings of hypoperfusion of the deep capillary plexus in a patient with acute on chronic cocaine use.

Cerebrovascular and cardiovascular diseases caused by drugs of abuse

Drugs such as stimulants, sedatives, sleeping pills, and narcotics are associated with drug abuse and are therefore regulated by law. Physical dependence on these drugs is sometimes difficult to control despite an awareness of the problems they cause in daily life and the harm they can cause to the body. Drug dependence is a social problem worldwide, and the physical implications are serious. Many of these drugs cause cerebrovascular and cardiovascular diseases, which often require emergency medical treatment. Differential diagnosis is essential because of the likelihood of life-threatening events, especially among young people who exhibit cerebrovascular and cardiovascular diseases without any of the typical risk factors. Drugs of abuse, especially stimulants, induce a hyperadrenergic state that evokes vasoconstriction and tachycardia, as well as subsequent ischemic and hemorrhagic stroke, acute coronary syndrome, arrhythmias, and aortic dissection. Chronic drug abuse can also cause cardiac hypertrophy and left ventricular dysfunction. As a treatment for these conditions, sedative drugs can be effective but the use of vasodilators may also be required. There are concerns that the use of both alpha- and beta-adrenergic receptor blockers may cause tachycardia and increased blood pressure. Therefore, careful differential diagnosis and selection of therapeutic agents is required.

Acute and Chronic Effects of Cocaine on Cardiovascular Health

Cardiac complications resulting from cocaine use have been extensively studied because of the complicated pathophysiological mechanisms. This study aims to review the underlying cellular and molecular mechanisms of acute and chronic effects of cocaine on the cardiovascular system with a specific focus on human studies. Studies have consistently reported the acute effects of cocaine on the heart (e.g., electrocardiographic abnormalities, acute hypertension, arrhythmia, and acute myocardial infarction) through multifactorial mechanisms. However, variable results have been reported for the chronic effects of cocaine. Some studies found no association of cocaine use with coronary artery disease (CAD), while others reported its association with subclinical coronary atherosclerosis. These inconsistent findings might be due to the heterogeneity of study subjects with regard to cardiac risk. After cocaine use, populations at high risk for CAD experienced coronary atherosclerosis whereas those at low risk did not experience CAD, suggesting that the chronic effects of cocaine were more likely to be prominent among individuals with higher CAD risk. Studies also suggested that risky behaviors and cardiovascular risks may affect the association between cocaine use and mortality. Our study findings highlight the need for education regarding the deleterious effects of cocaine, and access to interventions for cocaine abusers.

Cocaine and coronary artery diseases: a systematic review of the literature

Cocaine is associated with important cardiac complications such as sudden death, acute myocarditis, dilated cardiomyopathy, life-threatening arrhythmias, and myocardial ischemia as well as infarction. It is well known that cocaine may induce vasospasm through adrenergic stimulation of the coronary arteries. Moreover, cocaine may promote intracoronary thrombosis, triggered by alterations in the plasma constituents, and platelet aggregation, leading to subsequent myocardial infarction. The long-term use of cocaine may stimulate atherosclerosis, probably through endothelial cell dysfunction. Significant and severe coronary atherosclerosis is common in young chronic cocaine users and there is probably a relationship between the duration and frequency of cocaine use and the extent of coronary disease.

The Cardiovascular Effects of Cocaine

Cocaine is the leading cause for drug-abuse-related visits to emergency departments, most of which are due to cardiovascular complaints. Through its diverse pathophysiological mechanisms, cocaine exerts various adverse effects on the cardiovascular system, many times with grave results. Described here are the varied cardiovascular effects of cocaine, areas of controversy, and therapeutic options.

Cardiorespiratory fitness and body composition of stimulant users: A baseline analysis of the STRIDE cohort

INTRODUCTION

Relatively little has been reported about the physical characteristics, such as cardiorespiratory fitness (CRF) and body composition, of stimulant users. Identifying risk factors associated with the physical health of stimulant users is an important public health issue as new treatments should better address the entire range of health concerns experienced by this population.

METHODS

We examined cross-sectional data gathered at baseline from the STimulant Reduction Intervention using Dosed Exercise (STRIDE) study, a multisite randomized clinical trial that examined exercise as an adjunct to treatment as usual for individuals in residential treatment programs (RTPs). Clients were approached after intake to the RTP. Prior to randomization, eligible individuals underwent a comprehensive screening process that included medical screening, where CRF was assessed through a maximal exercise test (time on treadmill), and a series of baseline examinations assessing domains of substance use and mental health.

RESULTS

Data from 295 individuals with recent stimulant use disorders were analyzed. The mean body mass index (BMI) and waist circumference (WC) and for all participants was 27.8±5.7kg/m² and 93.5±14.2cm, respectively, while the mean time on treadmill was 13.7±2.9min. Few significant associations were observed between CRF, BMI, or WC and substance use and mental health measures.

CONCLUSIONS

Stimulant users in this study presented with low CRF levels and would be considered overweight based on their BMI. These individuals would likely benefit from interventions that address both their stimulant use, as well as their physical health.

β-Blockers, Cocaine, and the Unopposed α-Stimulation Phenomenon

Cocaine abuse remains a significant worldwide health problem. Patients with cardiovascular toxicity from cocaine abuse frequently present to the emergency department for treatment. These patients may be tachycardic, hypertensive, agitated, and have chest pain. Several pharmacological options exist for treatment of cocaine-induced cardiovascular toxicity. For the past 3 decades, the phenomenon of unopposed α-stimulation after β-blocker use in cocaine-positive patients has been cited as an absolute contraindication, despite limited and inconsistent clinical evidence. In this review, the authors of the original studies, case reports, and systematic review in which unopposed α-stimulation was believed to be a factor investigate the pathophysiology, pharmacology, and published evidence behind the unopposed α-stimulation phenomenon. We also investigate other potential explanations for unopposed α-stimulation, including the unique and deleterious pharmacologic properties of cocaine in the absence of β-blockers. The safety and efficacy of the mixed β-/α-blockers labetalol and carvedilol are also discussed in relation to unopposed α-stimulation.

Cocaine Constrictor Mechanisms of the Cerebral Vasculature

Cocaine constriction of the cerebral vasculature is thought to contribute to the ischemia associated with cocaine use. However, the mechanisms whereby cocaine elicits relevant vasoconstriction remain elusive. Indeed, proposed intra- and intercellular mechanisms based on over 3 decades of ex vivo vascular studies are, for the most part, of questionable relevancy due to the generally low contractile efficacy of cocaine combined with the use of nonresistance-type vessels. Furthermore, the significance attached to mechanisms derived from in vivo animal studies may be limited by the inability to demonstrate cocaine-induced decreased cerebral blood flow, as observed in (awake) humans. Despite these apparent limitations, we surmise that the vasoconstriction relevant to cocaine-induced ischemia is elicited by inhibition of dilator and activation of constrictor pathways because of cocaine action on the neurovascular unit (neuron, astrocyte, and vessel) and on vessels outside the unit. Furthermore, previous cocaine exposure, that is, conditions present in human subjects, downregulates and sensitizes these dilator and constrictor pathways, respectively, thereby enhancing constriction to acute cocaine. Identification of specific intra- and intercellular mechanisms requires investigations in the isolated microvasculature and the neurovascular unit from species chronically exposed to cocaine and in which cocaine decreases cerebral blood flow.

Cardiovascular and Hepatic Toxicity of Cocaine: Potential Beneficial Effects of Modulators of Oxidative Stress

Oxidative stress (OS) is thought to play an important role in the pharmacological and toxic effects of various drugs of abuse. Herein we review the literature on the mechanisms responsible for the cardiovascular and hepatic toxicity of cocaine with special focus on OS-related mechanisms. We also review the preclinical and clinical literature concerning the putative therapeutic effects of OS modulators (such as N-acetylcysteine, superoxide dismutase mimetics, nitroxides and nitrones, NADPH oxidase inhibitors, xanthine oxidase inhibitors, and mitochondriotropic antioxidants) for the treatment of cocaine toxicity. We conclude that available OS modulators do not appear to have clinical efficacy.

Cocaine and kidney injury: a kaleidoscope of pathology

Cocaine is abused worldwide as a recreational drug. It is a potent activator of the sympathetic nervous system leading to intense vasoconstriction, endothelial dysfunction, oxidative stress, platelet activation and decrease in prostaglandins E2 and prostacyclin. Cocaine can lead to widespread systemic adverse effects such as stroke, myocardial infarction, arterial dissection, vascular thrombosis and rhabdomyolysis. In human and rat kidneys, cocaine has been associated with glomerular, tubular, vascular and interstitial injury. It is not uncommon to diagnose cocaine-related acute kidney injury (AKI), malignant hypertension and chronic kidney disease. Cocaine abuse can lead to AKI by rhabdomyolysis, vasculitis, infarction, thrombotic microangiopathy and malignant hypertension. It is reported that 50–60% of people who use both cocaine and heroin are at increased risk of HIV, hepatitis and additional risk factors that can cause kidney diseases. While acute interstitial nephritis (AIN) is a known cause of AKI, an association of AIN with cocaine is unusual and seldom reported. We describe a patient with diabetes mellitus, hypertension and chronic hepatitis C, who presented with AKI. Urine toxicology was positive for cocaine and a kidney biopsy was consistent with AIN. Illicit drugs such as cocaine or contaminants may have caused AIN in this case and should be considered in the differential diagnosis of causes of AKI in a patient with substance abuse. We review the many ways that cocaine adversely impacts on kidney function.

MRI assessment of cerebral oxygen metabolism in cocaine-addicted individuals: hypoactivity and dose dependence

Long-term cocaine use is known to negatively impact neural and cerebrovascular systems. However, the use of imaging markers to separately assess these parameters remains challenging. The primary reason is that most functional imaging markers, such as cerebral blood flow, functional connectivity, and task-evoked functional MRI, are known to reflect a complex interplay between neural and vascular components, thus the interpretation of the results is not straightforward. The goal of the present study is to examine neural-activity-specific changes in cocaine addiction, using cerebral metabolic rate of oxygen (CMRO2) as a surrogate marker of aggregated neural activity. We applied a recently developed CMRO2 technique in 13 cocaine-addicted subjects and 13 age- and gender-matched control subjects, and examined the impact of long-term cocaine use on CMRO2. Our results showed that CMRO2 in cocaine-addicted subjects (152 ± 16 µmol/100 g/min) is significantly lower (p = 0.031) than that in controls (169 ± 20 µmol/100 g/min). Furthermore, the severity of this decreased metabolism is associated with lifetime cocaine use (p = 0.05). Additionally, the CMRO2 reduction was accompanied by a trend of decrease in cerebral blood flow (p = 0.058), but venous oxygenation was unaffected (p = 0.96), which suggested that the CMRO2 change may be attributed to a vascular deficiency in chronic cocaine users. To our knowledge, this is the first study to measure CMRO2 in cocaine-addicted individuals. Our findings suggest that CMRO2 may be a promising approach for assessing the long-term effects of cocaine use on the brain.

Cocaine induced hippocampi infarction

A middle age man presented with disorientation and memory impairment due to bilateral hippocampal strokes secondary to cocaine use. This is the second report of cocaine induced hippocampi ischaemic strokes. In contrast to the previous report, this middle age man did not have cardiac arrest.

Effect of the single or combined administration of cocaine and testosterone on cardiovascular function and baroreflex activity in unanesthetized rats

Abuse of cocaine and androgenic-anabolic steroids has become a serious public health problem. Despite reports of an increase in the incidence of simultaneous illicit use of these substances, potential toxic interactions between cocaine and androgenic-anabolic steroids in the cardiovascular system are unknown. In the present study, we investigated the effect of single or combined administration of testosterone and cocaine for 1 or 10 consecutive days on basal cardiovascular parameters, baroreflex activity, and hemodynamic responses to vasoactive agents in unanesthetized rats. Ten-day combined administration of testosterone and cocaine increased baseline arterial pressure. Changes in arterial pressure were associated with altered baroreflex activity and impairment of both hypotensive response to intravenous sodium nitroprusside and pressor effect of intravenous phenylephrine. Chronic single administration of either testosterone or cocaine did not affect baseline arterial pressure. However, testosterone-treated animals presented rest bradycardia, cardiac hypertrophy, alterations in baroreflex activity, and enhanced response to sodium nitroprusside. Repeated administration of cocaine affected baroreflex activity and impaired vascular responsiveness to both sodium nitroprusside and phenylephrine. One-day single or combined administration of the drugs did not affect any parameter investigated. In conclusion, the present results suggest a potential interaction between toxic effects of cocaine and testosterone on the cardiovascular activity. Changes in baseline arterial pressure after combined administration of these 2 drugs may result from alterations in baroreflex activity and impairment of vascular responsiveness to vasoactive agents.

[Anomalous origin of the right coronary artery and acute myocardial infarction: cause or coincidence?]

Congenital coronary artery anomalies are one of the causes of myocardial ischemia and sudden death in the young, mainly during sports. Origin of the right coronary artery from the left anterior descending artery is very rare, with a prevalence of 0.015%, corresponding to 1.2% of all coronary artery anomalies. The authors present the case of a 22-year-old man, with a history of cocaine use, admitted to hospital with a non-ST elevation acute myocardial infarction. Coronary angiography revealed the presence of this rare coronary anomaly and the absence of atherosclerotic luminal stenosis, and so it was assumed to be a type II infarction caused by cocaine-induced vasospasm of the anomalous vessel.

Increased number of circulating endothelial cells and plasma markers of endothelial damage in chronic cocaine users

BACKGROUND

Cocaine use has been related with the development of accelerated atherosclerosis and with an increased risk of cardiac and cerebrovascular events, such as myocardial infarction, sudden cardiac death, and ischemic stroke. The underlying mechanisms leading to these complications are not fully understood, although thrombus formation and altered vascular function are prominent findings.

OBJECTIVES

Our aim was to evaluate markers of endothelial dysfunction in chronic cocaine consumers before and after drug withdrawal.

PATIENTS/METHODS

We determined circulating endothelial cells (CECs) and plasma levels of stromal cell-derived factor-1 (SDF-1), monocyte chemotactic protein-1(MCP-1), soluble intracellular adhesion molecule (sICAM), high-sensitivity C reactive protein (hsCRP) and endothelin-1(ET-1), in DSM-IV cocaine addicts at baseline and after one month of cocaine abstinence.

RESULTS

Cocaine users showed a strikingly higher numbers of CEC (62.35 ± 18.4 vs 8.25 ± 13.8 CEC/mL) and significantly elevated plasma levels for all the markers evaluated as compared to the control group. After cocaine withdrawal, patients improved SDF-1, ET-1, hsCRP and sICAM levels. However, CEC number and MCP-1 plasma levels remained significantly elevated. All the results were adjusted for blood levels of cholesterol and triglycerides and for smoking habit.

CONCLUSIONS

Our results demonstrated that chronic cocaine consumption alters several functions of the endothelium towards a pro-thrombotic condition and that some of those functions remain abnormal even after short-term drug withdrawal. These observations support the notion that endothelial dysfunction may play a key role in the pathogenesis of ischemic vascular disease observed in cocaine abusers.

Effects of labetalol on hemodynamic parameters and soluble biomarkers of inflammation in acute coronary syndrome in patients with active cocaine use

Cocaine use is associated with increased cardiovascular mortality and can promote acute coronary syndrome (ACS). Use of beta-blockers is controversial in patients who use cocaine, and the safety and efficacy of these medications in ACS in patients actively using cocaine is unknown. We enrolled 90 patients with ACS and positive urine drug screen for cocaine. Patients received standard ACS therapy plus either labetalol (n = 60) or diltiazem (n = 30). Blood pressure and heart rate were measured at baseline and 48 hours. Levels of serum CD40 ligand, interleukin (IL)-6, and choline at baseline and 48 hours were determined. There were no baseline differences in hemodynamics or serum levels of inflammatory markers between the labetalol and diltiazem groups. Both groups experienced a significant and equivalent decrease in BP and HR at 48 hours compared with baseline. At 48 hours of treatment, there were significant decreases of 17% in CD40 ligand (P < .005) and 16% in IL-6 (P < .005) but no change in choline in the diltiazem group. Furthermore, in the labetalol group, there were significant differences of 30% in CD40 ligand (P < .005 time and group comparison), 22% in IL-6 (P < .005 time and group comparison), and 18% in choline (P < .005 time and group comparison). There were no adverse events during hospitalization in any patients who received labetalol. In conclusion, labetalol appears to be safe in cocaine-associated ACS. Furthermore, labetalol provides a beneficial hemodynamic response and, in comparison to diltiazem, potentiates an anti-inflammatory vascular response in this setting.

Outcomes of coronary artery bypass grafting in patients with a history of opiate use

This study aimed at evaluating the outcome of CABG in patients with a history of opiate use. Two hundred male patients, underwent CABG surgery, were evaluated and followed up for 6 months. The patients classified as Group P (with Previous history of opiate use) and Group N (with No history of opiate use). The characteristics and 6-month outcomes were compared between the two groups. Patients in group P further categorized into two subgroups of active and non-active abusers. Two hundred male-patients enrolled in the study, 23 (11.5%) patients had a history of opiate abuse. Nine (4.5%) patients were past users and 14 (7%) cases were current users. There were no significant differences regarding the age, history of hypertension, smoking, ejection fraction before and 6 months after CABG, duration of hospital stay, complications of surgery and function class (p<0.05). The level of patients obeys from physician's medical, nutritional and activity recommendations after CABG was significantly lower for current opiate users. Also, the need for readmission after CABG due to cardiac complications was independently higher in current opiate users. Carrying out the educational programs to correct the misconception about the beneficial effects of illicit drugs on cardio-vascular disease makes sense.

The relationship of drug abuse to unexplained sudden death

CONTEXT

Forensic pathologists regularly investigate the deaths of individuals with a history of drug abuse. Autopsy, including toxicology testing, reveals no cause for death in a subset of this cohort.

OBJECTIVE

To determine whether deaths with an undetermined cause and manner of death are associated with a history of drug abuse.

DESIGN

Retrospective matched case-control study of 52 decedents whose cause of death remained undetermined following autopsy, matched 1:2 to a control group of living patients admitted for cholecystectomy according to age and date of death or procedure.

RESULTS

Individuals whose cause of death was undetermined were 5.3 times (95% confidence interval, 1.9-14.5) more likely to have a history of drug abuse than were patients with cholecystitis.

CONCLUSIONS

Decedents with a history of chronic drug abuse appear to be at an increased risk of dying by their chronic drug abuse, even in the absence of any anatomical or toxicologic finding at autopsy to account for death.

Molecular analysis of cocaine-induced endothelial dysfunction: role of endothelin-1 and nitric oxide

Cocaine remains the most frequently used illicit substance. Although cocaine-induced atherosclerosis is well documented, its mechanism of action on human vascular endothelial cells has not been determined. Nitric oxide (NO) and endothelin-1 (ET-1) are involved in endothelial cell activation and leukocyte recruitment. The present study monitored the effects of cocaine on NO and ET-1 production in human aortic endothelial cells (HAECs) and the effects of sodium nitroprusside (SNP) and BQ-123 on leukocyte adhesion to HAECs. Acute exposure to cocaine (1 and 3 muM) significantly increased ET-1 production (2-fold) and ET-1 receptor type-A (ET(A)R) protein expression, within 6-12 h. Cocaine exposure for a longer duration (24-72 h) showed a temporal decrease in both NO production and endothelial NO-synthase (eNOS) expression. The cocaine-mediated suppression of NO was ameliorated by co-treatment of cells with the ET(A)R blocker, BQ-123 (5 muM). Furthermore, both short-term (24 h) and long-term (72 h) exposure to cocaine increased endothelial adhesion of monocytes (U937 cells) by 20% and 40%, respectively, which were also suppressed by BQ-123 and SNP co-treatment. These data suggest that a concomitant increase in both ET-1 and ET(A)R expression in cocaine exposed HAECs may enhance signaling via the ET(A)R which decreases eNOS expression and NO production, and ultimately results in endothelial activation and leukocyte adhesion. Our findings implicate a molecular mechanism of action of cocaine and a therapeutic effect of ET(A)R-specific inhibitor in suppressing the cocaine-induced endothelial dysfunction.

Acute stent thrombosis in the setting of cocaine abuse following percutaneous coronary intervention

The treatment of acute coronary syndrome (ACS) in patients with documented cocaine abuse has always presented significant challenges. Issues related to medication compliance, the potential risks of beta adrenergic blockade, and possible continued cocaine abuse postmyocardial infarction necessitate a unique, individualized approach to these patients. Recent data in the era of extensive percutaneous coronary interventions (PCI) and intracoronary stent (ICS) implantation have raised questions regarding the safety of ICS in patients who may revert to cocaine abuse postacute coronary syndrome as a result of the potentially higher risk of stent thrombosis in these patients. While the precise reason as to why cocaine use may increase the risk of stent thrombosis is not fully understood, it is likely the result of a confluence of factors, including coronary vessel vasoconstriction, impaired vascular compliance, as well as the platelet-activating effect of cocaine. We present the case a 46-year-old male with a history of cocaine abuse who presented with an acute stent thrombosis 2 days post-PCI likely as a result of cocaine abuse on the day of discharge following initial stent implantation for a non-ST-elevation myocardial infarction (NSTEMI). We also review the literature regarding the safety of PCI in cocaine abusers.

Peripheral Mechanisms of Erectile Dysfunction in a Rat Model of Chronic Cocaine Use

OBJECTIVE

To evaluate the peripheral mechanisms of erectile dysfunction (ED) in a rat model of triple-binge cocaine administration.

METHODS

Adult male Sprague-Dawley rats (n=24) were divided into two groups: group 1, control rats receiving vehicle (saline); group 2, rats receiving binge cocaine injections. After completion of triple-binge cocaine or saline injections, both groups underwent an in vivo, neurogenic-mediated erectile response protocol to assess intracavernosal pressure (ICP). Penile endothelin-A and -B receptors (ET(A)R and ET(B)R), plasma levels of big endothelin-1 (big-ET-1), and endothelial nitric oxide synthase (eNOS) protein expression were assessed. To analyze nitric oxide (NO) production, we measured plasma nitrate-nitrite levels and quantitated myeloperoxidase (MPO) activity in cavernosal tissues to determine reactive oxygen species generation. Endothelium-dependent and -independent relaxation responses were evaluated in vitro. Data were analyzed with Student t test.

RESULTS

Triple-binge cocaine administration caused significantly decreased erectile responses as measured by ICP in vivo. Plasma big-ET-1 levels were significantly increased in the triple-binge cocaine treatment group compared with control animals. In the penis, triple-binge cocaine administration significantly increased ET(A)R expression compared with saline controls, while ET(B)R expression was not altered. Cocaine-treated rats had significantly decreased eNOS expression and NO production. The activity of tissue MPO was significantly increased in the cocaine group compared with control rats. Organ bath studies demonstrated that triple-binge cocaine resulted in a 64% reduction in maximal relaxation compared with the control group.

CONCLUSION

This study demonstrates that triple-binge cocaine administration significantly reduces erectile function in rats. The pathophysiologic mechanisms that are likely involved include increased plasma big-ET-1 levels, increased penile ET(A)R expression, increased penile MPO activity, and reduced penile eNOS expression.

Endothelial function in HIV-infected persons

BACKGROUND

Several reports have suggested an increased risk of coronary disease in human immunodeficiency virus (HIV)-infected patients receiving protease inhibitors (PIs). Impaired endothelium-dependent vasodilation is a putative surrogate marker of coronary atherosclerotic disease.

METHODS

The present study evaluated the effect of HIV infection and antiretroviral treatment on endothelial vasomotor function, by assessing brachial artery flow-mediated dilation (FMD). A total of 75 HIV-infected patients were compared with 223 control subjects who were presumed to be HIV uninfected.

RESULTS

HIV-infected patients had significantly impaired FMD, compared with control subjects (mean +/- SD, 7.3% +/- 4.4% vs. 11.1% +/- 6.3%; P < .0001). When adjustments were made for smoking status, sex, and body mass index, the difference between the 2 groups remained statistically significant (P < .01). In a cross-sectional analysis of the HIV-infected patients, we found significant associations between FMD and current injection drug use, hazardous drinking, HIV load, and alpha-high-density lipoprotein triglyceride levels, but not PI therapy. In a multivariate analysis, only current injection drug use and a lower alpha-high-density lipoprotein triglyceride level were significantly associated with FMD.

CONCLUSIONS

HIV-infected patients have significant impairment of endothelial function, and this impairment is worse among those with elevated levels of HIV replication, particularly injection drug users.

Intravascular ultrasound-guided percutaneous coronary intervention in a human immunodeficiency virus-positive patient with cocaine-associated acute myocardial infarction: case report and review

Cocaine use is a major problem worldwide and there are numerous reports about cocaine-associated myocardial infarction. Nevertheless minimal data are available from randomised clinical trials to suggest evidence-based approaches to the management of cocaine-associated myocardial ischemia. Moreover, most reports have been limited to conservative management of cocaine-associated myocardial infarction. We report a case of a young male cocaine user with acute myocardial infarction, undergoing diagnostic coronary angiography and intravascular ultrasound revealing severe atherosclerosis, followed by successful stent implantation.

Enterocolitis associated with cocaine use

PURPOSE

Cocaine use has been reported to cause gastrointestinal complications. This retrospective review describes the presentation and clinical course of cocaine-associated enterocolitis.

METHODS

Charts with a diagnoses of colitis or abdominal pain, between 1991 to 2001, were reviewed for a positive urine drug screen or documented cocaine use. Data about the patients' symptoms and physical findings, results of clinical studies, and outcome were collected.

RESULTS

There were 18 patients identified. The interval from last use to the onset of pain was fewer than one day for seven patients, one to three days for seven patients, and more than three days for four patients. Physical examination demonstrated diffuse peritonitis in 2 patients, tenderness localized to a single quadrant in 11 patients, and tenderness in two or more quadrants in 5 patients. Computed tomography was obtained in 11 patients with 10 demonstrating signs of inflammation or ischemia. The anatomic locations of disease were proximal colon (14 patients), small bowel/gastric (1 patient), and distal colon (3 patients). The initial management was nonoperative in 15 patients. One patient presented in shock and died. Another developed peritonitis and underwent laparotomy. Surgical intervention occurred in four patients (3 initially, 1 on Day 4) for peritonitis. Two died postoperatively, a 50-percent surgical mortality.

CONCLUSIONS

Cocaine-associated enterocolitis usually presents within three days of cocaine use. Inflammatory or ischemic changes are most common in the proximal colon. The majority of patients will recover with nonoperative therapy; however, those who develop peritonitis and undergo laparotomy have a 50 percent mortality.

Down-regulation of astroglial CYP2C, glucocorticoid receptor and constitutive androstane receptor genes in response to cocaine in human U373 MG astrocytoma cells

Psychostimulant drugs abuse is associated with an increased risk of stroke. Cytochromes P450 (CYP), especially the astrocytic members of the CYP2C subfamily may play an important role in the modulation of cerebrovascular functions, by generating vasodilatator metabolites from arachidonic acid (AA). Our study examined the regulation of CYP2C genes in response to cocaine or amphetamine in the human astrocyte-like U373 MG cells, using reverse transcription-polymerase chain reaction (RT-PCR) and western-blot analysis. A treatment for 48h with increasing concentrations of cocaine caused a significant down-regulation of CYP2C8 and CYP2C9 genes and decreased the protein level. These effects were not observed with amphetamine. One mechanism of the CYP2C mRNA regulation implicates various specific receptors including glucocorticoid receptor (GR) and constitutive androstane receptor (CAR). Effects of cocaine on CYP2C were accompanied by a decrease in the GR and CAR gene expression suggesting that these nuclear receptors could be involved in the CYP2C repression by cocaine in the U373 MG cell line. These findings represent a possible molecular mechanism involved in the cerebrovascular risk associated with cocaine abuse.

Cocaine-induced renal disease

Cocaine has anaesthetic, vasoconstrictive and CNS stimulatory effects. Presently, it is used clinically as a local anaesthetic and abused as a recreational drug. It has been implicated in both acute and chronic renal failure and has been reported to affect every aspect of the nephron. This article will review the spectrum of cocaine-induced kidney disease and attempt to give insight into the pathophysiological mechanisms involved.

Effects of cocaine on nitric oxide production in bovine coronary artery endothelial cells

Cocaine decreases coronary artery endothelial-dependent vasorelaxation. To explore the potential mechanisms, the present study examined the effect of cocaine on nitric oxide release in bovine coronary artery endothelial cells (BCAECs). In the absence of cocaine, basal nitric oxide release from BCAECs continued to accumulate in the medium over the period from 6 to 72 h. Cocaine significantly decreased nitric oxide release at each time point of the study. At 48-h treatment, cocaine (3-30 muM) produced a concentration-dependent decrease in nitric oxide release in BCAECs. In accordance with its inhibition of nitric oxide release, cocaine decreased endothelial nitric-oxide synthase (eNOS) protein levels in BCAECs in a concentration-dependent manner. In addition to the prolonged effect, cocaine pretreatment for 1 h significantly decreased basal and ATP-induced nitric oxide release in BCAECs. Whereas acute cocaine treatment did not affect basal levels of free intracellular calcium concentrations in BCAECs, it significantly decreased the ATP-induced elevation of intracellular calcium and increased its time lag to reach the peak. A quantitative approach by immunofluorescence microscopy revealed that cocaine significantly increased eNOS localized at the cell membrane in BCAECs. Collectively, the results suggest that cocaine inhibits nitric oxide release in BCAECs by decreasing intracellular calcium mobilization, increasing the inactive state of eNOS, and decreasing eNOS protein levels.

Effect of binge cocaine treatment on hindlimb vascular function

Chronic cocaine abuse is known to cause endothelial dysfunction and atherosclerosis. The present study investigated the effect of binge cocaine treatment, a model for chronic cocaine abuse, on the blood flow responses to the adrenergic agonists norepinephrine, phenylephrine and isoproterenol, the endothelium-dependent vasodilator acetylcholine, and the endothelium independent vasodilator sodium nitroprusside (SNP) in the hindlimb vascular bed of male Sprague Dawley rats. Rats received either single binge or double binge treatment. Each binge treatment consisted of three doses of cocaine (30 mg kg(-1) i.p.) for 3 days. For double binge treatment, there was a 4 day recovery period between the binges. At the end of the treatment the rats were anesthetized and agonists were administered into the right hindlimb circulation through a catheter in the left iliac artery and blood flow responses were measured with a flow probe around the right iliac artery. Rats receiving double cocaine binges showed a significant decrease in the magnitude and duration of the blood flow response to norepinephrine and a decrease in the duration of the blood flow response to phenylephrine, isoproterenol and acetylcholine when compared with saline controls. The blood flow response to SNP was not changed. Total plasma nitrate-nitrite levels were significantly reduced and big endothelin levels were significantly increased in rats receiving double cocaine binges. This study demonstrates that binge cocaine treatment can alter endothelial function, while not changing smooth muscle function, and impairs the adrenergic pathway.