Recurrent myocardial infarction associated with cocaine abuse in a young man with normal coronary arteries: evidence for coronary artery spasm culminating in thrombosis

Acute Cardiovascular Toxicity of Cocaine

Cocaine is one of the most commonly abused drugs and represents a major public health concern. Cocaine users frequently present to the emergency department, with chest pain being the most common presenting complaint. The incidence of acute myocardial infarction in patients with cocaine-associated chest pain is often quoted as 6%, but it is highly variable depending on the included population. Risk assessment can be challenging in these patients; serial assessment of electrocardiograms and troponins is often required. This review focuses on the assessment and management of patients presenting with cocaine-associated chest pain and cardiotoxicity. Specific treatments are discussed, including benzodiazepines, nitroglycerin, calcium channel blockers, and phentolamine, and how treatment priorities differ from patients with noncocaine presentations. The use of beta-blockers in this population remains controversial, and the literature around its use is reviewed. The most recent literature and recommendations for the use of percutaneous coronary intervention and fibrinolytics in cocaine-associated myocardial infarction is discussed as well. Cocaine-associated dysrhythmias are suggested to be the cause of sudden cardiac death in some users. The pathophysiology and evidence-based treatments for dysrhythmias are reviewed. This review provides evidence-based recommendations for the assessment and management of patients presenting with cocaine-associated cardiovascular toxicity.

Peripartum myocardial infarction associated with coronary spasm and acquired protein S deficiency: A case report

RATIONALE

Coronary angiography (CAG) findings of acute myocardial infarction (AMI) in pregnant women are characterized by a high incidence of normal coronary arteries. This is the first report of AMI with normal coronary arteries during pregnancy, showing coronary spasm and pregnancy-related acquired protein S (PS) deficiency.

PATIENT CONCERNS

A 30-year-old Japanese woman was admitted to an emergency department. One hour before admission, she developed sudden onset of precordial discomfort, back pain, and dyspnea. She was a primigravida at 39 weeks' gestation and had no abnormality in the pregnancy thus far. She had no history of heart disease, diabetes, hypertension, dyslipidemia, deep vein thrombosis (DVT), smoking, or oral contraceptive use and no family history of ischemic heart disease, hemostasis disorder, or DVT. She did not take any medication.

DIAGNOSIS

Electrocardiography showed ST-segment elevations in leads II, III, aVF, and V2-V6. Heart-type fatty acid-binding protein was positive. Echocardiography showed hypokinesis of the anterior interventricular septum and inferior wall. Continuous intravenous infusion of isosorbide dinitrate was initiated. Coronary computed tomography angiography revealed diffuse narrowing of the apical segment of the left anterior descending coronary artery. Three hours after admission, troponin T became positive, and the following enzymes reached their peak levels: creatine kinase (CK), 1,886 U/L; CK-muscle/brain, 130 U/L. She was diagnosed with transmural AMI due to severe coronary spasm and administered benidipine hydrochloride. Five hours after admission, premature membrane rupture occurred.

INTERVENTIONS

Emergency cesarean section was performed. There were no anesthetic or obstetrical complications during the operation. On postpartum day 1, the free PS antigen level was low (29%). On postpartum day 18, she was discharged with no reduction in physical performance.

OUTCOMES

Four months after the infarction, CAG showed normal coronary arteries. Acetylcholine provocation test showed diffuse vasospasm in the coronary artery. She was advised that her next pregnancy should be carefully planned. Two years after delivery, free PS antigen level was within normal range, at 86%. She had not experienced recurrence of angina during the 2-year period. Her child was also developing normally.

LESSONS

In addition to coronary spasm, pregnancy-related acquired PS deficiency may be involved in AMI etiology.

Treatment of cocaine cardiovascular toxicity: a systematic review

INTRODUCTION

Cocaine abuse is a major worldwide health problem. Patients with acute cocaine toxicity presenting to the emergency department may require urgent treatment for tachycardia, dysrhythmia, hypertension, and coronary vasospasm, leading to pathological sequelae such as acute coronary syndrome, stroke, and death.

OBJECTIVE

The objective of this study is to review the current evidence for pharmacological treatment of cardiovascular toxicity resulting from cocaine abuse.

METHODS

MEDLINE, PsycINFO, Database of Abstracts of Reviews of Effects (DARE), OpenGrey, Google Scholar, and the Cochrane Library were searched from inception to November 2015. Articles on pharmacological treatment involving human subjects and cocaine were selected and reviewed. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines. Treatment recommendations were compared to current American College of Cardiology/American Heart Association guidelines. Special attention was given to adverse drug events or treatment failure. The search resulted in 2376 articles with 120 eligible involving 2358 human subjects. Benzodiazepines and other GABA-active agents: There were five high-quality (CEBM Level I/II) studies, three retrospective (Level III), and 25 case series/reports (Level IV/V) supporting the use of benzodiazepines and other GABA-active agents in 234 subjects with eight treatment failures. Benzodiazepines may not always effectively mitigate tachycardia, hypertension, and vasospasm from cocaine toxicity. Calcium channel blockers: There were seven Level I/II, one Level III, and seven Level IV/V studies involving 107 subjects and one treatment failure. Calcium channel blockers may decrease hypertension and coronary vasospasm, but not necessarily tachycardia. Nitric oxide-mediated vasodilators: There were six Level I/II, one Level III, and 25 Level IV/V studies conducted in 246 subjects with 11 treatment failures and two adverse drug events. Nitroglycerin may lead to severe hypotension and reflex tachycardia. Alpha-adrenoceptor blocking drugs: There were two Level I studies and three case reports. Alpha-1 blockers may improve hypertension and vasospasm, but not tachycardia, although evidence is limited. Alpha-2-adrenoceptor agonists: There were two high-quality studies and one case report detailing the successful use of dexmedetomidine. Beta-blockers and β/α-blockers: There were nine Level I/II, seven Level III, and 34 Level IV/V studies of β-blockers, with 1744 subjects, seven adverse drug events, and three treatment failures. No adverse events were reported for use of combined β/α-blockers such as labetalol and carvedilol, which were effective in attenuating both hypertension and tachycardia. Antipsychotics: Seven Level I/II studies, three Level III studies, and seven Level IV/V case series and reports involving 168 subjects have been published. Antipsychotics may improve agitation and psychosis, but with inconsistent reduction in tachycardia and hypertension and risk of extrapyramidal adverse effects. Other agents: There was only one high level study of morphine, which reversed cocaine-induced coronary vasoconstriction but increased heart rate. Other agents reviewed included lidocaine, sodium bicarbonate, amiodarone, procainamide, propofol, intravenous lipid emulsion, propofol, and ketamine.

CONCLUSIONS

High-quality evidence for pharmacological treatment of cocaine cardiovascular toxicity is limited but can guide acute management of associated tachycardia, dysrhythmia, hypertension, and coronary vasospasm. Future randomized prospective trials are needed to evaluate new agents and further define optimal treatment of cocaine-toxic patients.

Cardiac and non-cardiac causes of T-wave inversion in the precordial leads in adult subjects: A Dutch case series and review of the literature

AIM: To describe the electrocardiographic (ECG) phenomena characterized by T-wave inversion in the precordial leads in adults and to highlight its differential diagnosis.

METHODS: A retrospective chart review of 8 adult patients who were admitted with ECG T-wave inversion in the anterior chest leads with or without prolongation of corrected QT (QTc) interval. They had different clinical conditions. Each patient underwent appropriate clinical assessment including investigation for myocardial involvement. Single and multimodality non-invasive, semi-invasive and invasive diagnostic approach were used to ascertain the diagnosis. The diagnostic assessment included biochemical investigation, cardiac and abdominal ultrasound, cerebral and chest computed tomography, nuclear medicine and coronary angiography.

RESULTS: Eight adult subjects (5 females) with a mean age of 66 years (range 51 to 82) are analyzed. The etiology of T-wave inversion in the precordial leads were diverse. On admission, all patients had normal blood pressure and the ECG showed sinus rhythm. Five patients showed marked prolongation of the QTc interval. The longest QTc interval (639 ms) was found in the patient with pheochromocytoma. Giant T-wave inversion (≥ 10 mm) was found in pheochromocytoma followed by electroconvulsive therapy and finally ischemic heart disease. The deepest T-wave was measured in lead V₃ (5 ×). In 3 patients presented with mild T-wave inversion (patients 1, 5 and 4 mm), the QTc interval was not prolonged (432, 409 and 424 msec), respectively.

CONCLUSION: T-wave inversion associated with or without QTc prolongation requires meticulous history taking, physical examination and tailored diagnostic modalities to reach rapid and correct diagnosis to establish appropriate therapeutic intervention.

Cardiac abnormalities in HIV-positive patients: results from an observational study in India

BACKGROUND

The clinical presentation of cardiac abnormalities in HIV-infected patients may be atypical or masked by concurrent illnesses that lead to misdiagnosis or they remain undiagnosed; therefore, this study was aimed to determine the frequency of cardiac abnormalities in HIV-infected patients.

MATERIAL AND METHODS

Consecutive HIV-infected patients of age >13 years were studied for 3 months, after obtaining their consent. After clinical assessment, chest x-ray, electrocardiogram, 2-dimensional echocardiography and serum Troponin T levels were done.

RESULTS

A total of 100 patients were studied, cardiomegaly was observed in the x-ray of 15% of them, abnormal electrocardiogram was seen in 18%, 2-dimensional echocardiography was abnormal in 67%; and diastolic dysfunction (42.8%) was the commonest abnormality followed by dilated cardiomyopathy (17.6%). Serum troponin T was elevated in 8%. The variables, opportunistic infections (OIs), antiretroviral therapy (ART), stage of HIV disease, and CD4 counts, did not affect the frequency of diastolic dysfunction.

CONCLUSION

The diastolic dysfunction is the most common cardiac abnormality observed in HIV-infected patients.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Cocaine and the heart

The use of cocaine may be associated with either acute or chronic toxicity, and approximately 5% to 10% of emergency department visits in the United States are believed to be secondary to cocaine usage. Chest pain is the most common cocaine-related medical problem, leading to the evaluation of approximately 64,000 patients annually for possible myocardial infarction, of which approximately 57% are admitted to the hospital, resulting in an annual cost greater than $83 million. There is a plethora of cocaine-related cardiovascular complications, including acute myocardial ischemia and infarction, arrhythmias, sudden death, myocarditis, cardiomyopathy, hypertension, aortic ruptures, and endocarditis. There is no evidence to suggest that preexisting vascular disease is a prerequisite for the development of a cocaine-related cardiovascular event, although it may be a potentiating factor, as may be nicotine and alcohol.

Cocaine causes atrial Purkinje fiber damage

Comparisons of atrial tissues from Syrian hamster offspring born from cocaine-treated mothers during the last days of pregnancy with sham-treated ones demonstrate irreversible focal ischemic damage in the Purkinje myofibers and minor endocardial damages as well as minute cardiomyocyte vacuolization. These defects are consistent with the pharmacotoxicity of cocaine or its metabolites. The damaged Purkinje myocytes apparently remain in contact with adjacent cardiomyocytes but undergo autolytic process similar to that found in autoschizic cell death. Adjacent cell type(s) appear to segregate or engulf the injured cells. Data collected in this report demonstrate why clinical bradyarrhythmias, arrhythmias, or sudden death as cardiac arrest can be found in pre- and postnatal cocaine-abused babies as well as those found in young individuals caused by acute or chronic cocaine abuse.

Combined effects of cocaine and nicotine on cardiovascular performance in a canine model

BACKGROUND

With the proliferation of cocaine abuse, increased incidence of catastrophic cardiovascular events such as angina pectoris, myocardial infarction, ventricular arrhythmias, or sudden death are reported. Many of these patients also smoke cigarettes before and after cocaine use, leading to a high frequency of simultaneous exposure to both drugs. Cocaine's and nicotine's independent effects on cardiodynamics are well documented, but combined effects of both on complete cardiovascular hemodynamics remain unknown.

HYPOTHESIS

The study aimed to determine whether these effects are additive, synergistic, or antagonistic and was therefore designed to investigate the cardiovascular changes produced as a result of combined administration of cocaine and nicotine in a canine model.

METHODS

Initially, in phase 1, 30 experiments were performed to study the dose-response curve of both drugs. In phase II and III, 12 dogs were subjected to 30 experiments. In phase II, cocaine was given intravenously (IV) followed by nicotine. In phase III, sequence of drug administration was reversed to study the effects on hemodynamics and coronary artery blood flow reserve.

RESULTS

Hemodynamic parameters observed were Phase I: Dose-response curve established the IV bolus dose of cocaine 2 mg/kg and nicotine 50 microg/kg. Phase II: Cocaine increased heart rate, blood pressure, and dP/dt, but nicotine administration after cocaine produced marked significant synergistic excitatory effects: dP/dt increased from 1,810 +/- 210 to 6,300 +/- 460 (p < 0.003). Phase III: Nicotine significantly increased heart rate, mean arterial pressures, left ventricular end-diastolic pressure, pulmonary artery, pulmonary capillary wedge, and right atrial pressures. Nicotine increased dP/dt (1,810 +/- 192 to 5,000 +/- 160 mmHg/s; p < 0.004). These excitatory effects of nicotine were attenuated by cocaine when administered as a second drug (dP/dt decreased to 1,925 +/- 144 from 5,000 +/- 160 mmHg/s;p < 0.004).

CONCLUSIONS

Cocaine, when administered alone, caused increase in heart rate, blood pressure, and dP/dt, but nicotine showed a significant increase in all the hemodynamic parameters. Both drugs reduced coronary blood flow reserve. In combination, cocaine plus nicotine administration had synergistic excitatory effects in dogs. A reversed drug combination, that is, nicotine plus cocaine, attenuated the excitatory effects of nicotine.

Longitudinal Substance Use following an Emergency Department Visit for Cocaine-Associated Chest Pain

Substance abuse is a chronic, relapsing condition, yet some individuals over time seem to cease use for factors that are largely unclear. A life threatening episode of cocaine-associated chest pain requiring an emergency department (ED) visit may influence subsequent use. A consecutive cohort (n = 219) of patients who presented to a large, urban ED with cocaine-associated chest pain was interviewed at baseline, three months, six months, and 12 months to evaluate longitudinal rates of subsequent drug use. Overall, there was a significant decrease in cocaine use over time (baseline = 100.0%, three months = 56.5%, six months = 54.2%, and 12 months = 51.7%, p < .05 for baseline versus each follow-up interval). Findings suggest that substance use declines following an ED visit for cocaine-related chest pain. However, about half of the subjects were still using cocaine one year later. Future studies examining the potential impact of brief interventions or case management to intervene with this not-in-treatment ED population are warranted.

Mitochondrial DNA impairment in nucleoside reverse transcriptase inhibitor-associated cardiomyopathy

Acquired immune deficiency syndrome (AIDS) is a global epidemic that continues to escalate. Recent World Health Organization estimates include over 33 million people currently diagnosed with HIV/AIDS. Another 20 million HIV-infected individuals died over the past quarter century. Antiretrovirals are effective treatments that changed the outcome of HIV infection from a fatal disease to a chronic illness. Cardiomyopathy (CM) is a bona fide component of HIV/AIDS with occurrence that is higher in HIV positive individuals. CM may result from individual or combined effects of HIV, immune reactions, or toxicities of prolonged antiretrovirals. Nucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of antiretroviral therapy. Despite pharmacological benefits of NRTIs, NRTI side effects include increased risk for CM. Clinical observations and in vitro and in vivo studies support various mechanisms of CM. This perspective highlights some of the hypotheses and focuses on mitochondrial-associated pathways of NRTI- related CM.

Cocaine-induced acute myocardial infarction

Acute myocardial infarction may occur following cocaine use. Cocaine-induced infarction is particularly common in younger patients aged 18 to 45 years old. Patients may or may not have angiographic evidence of coronary artery disease at the time of their acute event. Previous studies have shown that coronary artery spasm occurs with cocaine use, and perhaps platelet activation, both contributing to a process that may culminate in coronary artery occlusion. Primary coronary intervention should be the preferred revascularization modality by an experienced team. Thrombolytic therapy needs to be instituted if this intervention is unavailable. Beta blockers should be utilized with caution since they may increase coronary spasm or cause a paradoxical rise in blood pressure. They should be avoided in the early hours of the infarction, but be instituted prior to patient discharge. Interruption of cocaine abuse is the cornerstone of secondary prevention in cocaine-related myocardial infarction.

How toxic is cocaine?

The toxicities of cocaine are far-ranging. They include sudden death, acute medical and psychiatric illness, infectious complications, reproductive disturbances, trauma, criminal activities and societal disruption, including child neglect and abuse and lost job productivity. This chapter focuses on the medical complications. Medical complications in general reflect the intense sympathomimetic activities of cocaine ('sympathetic neural storm'). Psychiatric complications include acute anxiety or panic and paranoid psychosis. Cardiovascular complications include arrhythmias and sudden death, acute myocardial infarction, myocarditis, dissecting aneurysm and bowel infarction. Neurological complications include seizure, intracerebral haemorrhage and brain injury due to hyperthermia and/or seizures, and headache. The incidence of medical complications has been estimated using two databases collected prospectively in the United States. In 1989 and 1990 cocaine ranked first in total encounters, major medical complications and drug-related deaths. An attempt was made to assess the intrinsic toxicity of cocaine by computing the incidence of adverse health outcomes per population of drug abusers. Rates of emergency department visits and deaths were 15.1 and 0.5 respectively, per 1000 persons using drugs in the past year. The magnitude of the cocaine problem, while considerable, is relatively small compared with that of cigarette smoking or alcohol abuse.

Beta-blockers are associated with reduced risk of myocardial infarction after cocaine use

STUDY OBJECTIVE

Beta-blocker use is associated with coronary artery spasm after cocaine administration but also decreases mortality in patients with myocardial infarction or systolic dysfunction. We conduct a retrospective cohort study to analyze the safety of beta-blockers in patients with positive urine toxicology results for cocaine.

METHODS

The cohort consisted of 363 consecutive telemetry and ICU patients who were admitted to a municipal hospital and had positive urine toxicology results for cocaine during a 5-year period (307 patients). Fifteen patients with uncertain history of beta-blocker use before admission were excluded. The primary outcome measure was myocardial infarction; secondary outcome measure was inhospital mortality. Logistic regression analysis using generalized estimating equations models and propensity scores compared outcomes.

RESULTS

Beta-blockers were given in 60 of 348 admissions. The incidence of myocardial infarction after administration of beta-blocker was significantly lower than without treatment (6.1% versus 26.0%; difference in proportion 19.9%; 95% confidence interval [CI] 10.3% to 30.0%). One of 14 deaths occurred in patients who received beta-blockade (incidence 1.7% versus 4.5% without beta-blockade; difference in proportion 2.8%; 95% CI -1.2% to 6.7%). Multivariate analysis showed that use of beta-blockers significantly reduced the risk of myocardial infarction (odds ratio 0.06; 95% CI 0.01 to 0.61).

CONCLUSION

In our cohort, administration of beta-blockers was associated with reduction in incidence of myocardial infarction after cocaine use. The benefit of beta-blockers on myocardial function may offset the risk of coronary artery spasm.

Arterial Consequences of Recreational Drug Use

BACKGROUND

Recreational drug use is becoming an increasing problem throughout the world. Many of the drugs used and their routes of administration have the potential to cause damage to the vascular system. Intravenous drug administration with the risk of arterial puncture predisposes to the formation of infected pseudoaneurysms. Inadvertent intra-arterial injection predisposes to distal limb ischaemia. Cocaine has numerous effects not only on the heart, but also potentially on any vascular bed.

METHODS

A systematic review of published literature with regard to the arterial consequences of recreational drug abuse was undertaken by undergoing an electronic search.

RESULTS

Most of the available literature is in the form of case reports and case series. Pseudoaneurysm formation is a serious consequence for intravenous drug users. For femoral aneurysms vessel ligation is the safest option with a low amputation risk. A high proportion of patients do have symptoms of claudication in the long term. Intra-arterial injections can result in limb threatening ischaemia. Systemic anticoagulation forms the mainstay of treatment. Cocaine has significant effects upon both the myocardium and the arterial tree in general. Arterial problems must always be considered in cocaine users who present acutely.

CONCLUSION

The consequences of recreational drug use will result in an increased exposure of vascular surgeons to its associated complications posing unique and challenging problems.

Trauma associated with acute myocardial infarction in a multi-state hospitalized population

INTRODUCTION

Trauma has been suggested, in case series, as one of the nonatherosclerotic mechanisms leading to acute myocardial infarction (AMI), the leading cause of death in the US. AMI following non-penetrating injury has been shown to carry significant morbidity and mortality.

OBJECTIVE

To determine whether hospitalized injuries in a large multi state population are associated with increased risk of AMI during the initial hospital stay.

METHODS

Statewide injury hospital discharge data were collected from 19 states in 1997. Affected body regions of interest included thoracic, abdominal or pelvic, spine or back and blunt cardiac injury (BCI). The outcome of interest was AMI which was identified based on ICD-9-CM discharge diagnoses for the same visit. Unadjusted and adjusted multivariate logistic regression analyses were performed.

RESULTS

Independent of confounding factors and coronary arteriography (CA) status, BCI was associated with 2.6-fold increased risk for AMI in persons 46 years or older. When the diagnosis of AMI was confirmed by CA, BCI was associated with 8-fold risk elevation among patients 46 years and older and a 31-fold elevation among patients 45 years and younger. Abdominal or pelvic trauma, irrespective of confounding factors and CA status, was associated with a 65% increase in the risk of AMI among patients 45 years and younger and 93% increase in the risk of among patients 46 years and older. When the diagnosis of AMI was confirmed by CA, abdominal or pelvic trauma was associated with 6-fold risk elevation among patients 46 years and older.

CONCLUSION

Direct trauma to the heart, as characterized by a diagnosis of BCI, was observed to carry the greatest risk for AMI. Abdominal or pelvic trauma also increased the risk for AMI. Longitudinal studies are warranted to better understand the relationship between trauma and AMI.

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.

Cocaine-associated chest pain

Current estimates establish that more than 30 million people in the United States use cocaine. Cardiovascular complaints commonly occur among patients who present to emergency departments(EDs) after cocaine use, with chest pain the most common complaint in several studies. Although myocardial ischemia and infarction account for only a small percentage of cocaine-associated chest-pain, physicians must understand the pathophysiology of cocaine and appropriate diagnostic and treatment strategies to best manage these patients and minimize adverse outcomes. This article reviews the pharmacology of cocaine, its role in the pathogenesis of chest pain with specific emphasis on inducing myocardial ischemia and infarction, and current diagnostic and management strategies for cocaine-associated chest pain encountered in the ED.

The interaction of coronary tone and cardiac fibrosis

Regulation of coronary vascular tone is critical for proper perfusion and function of the myocardium. Many disease processes result in compromised regulation of coronary vascular tone and impaired myocardial perfusion. A common result of coronary vascular dysfunction is the development of areas of replacement fibrosis within the myocardium and surrounding the vasculature. Both intravascular processes, such as coronary atherosclerosis and endothelial dysfunction, and extravascular processes, including compromised myocardial metabolism, hormone excesses, and altered local signaling, may result in coronary vascular dysregulation. Coronary occlusion events, in turn, lead to myocardial damage and the activation of inflammatory cells and fibroblasts. The role of fibroblasts in regulating myocardial fibrosis and the contribution of myofibroblasts, cells that have limited contractile potential while retaining many of the extracellular matrix regulating processes of the fibroblast, may also contribute to the development of myocardial disease. In this review we examine the recent literature on myocardial fibrosis and myofibroblast activity, highlighting the effects of several classes of cardiovascular agents on the remodeling process.

The risk for mild kidney function decline associated with illicit drug use among hypertensive men

BACKGROUND

Few studies have examined the deleterious effect of illicit drug use on kidney function.

METHODS

Six hundred forty-seven patients enrolled in the Hypertension Clinic of the Veterans Administration Medical Center of New Orleans, LA, were interviewed regarding illicit drug use and followed up for a median of 7 years to determine the incidence of mild kidney function decline (increase in serum creatinine level > or = 0.6 mg/dL [> or =53.0 micromol/L]) between 1977 and 1999.

RESULTS

Twenty-three percent of study participants reported the use of illicit drugs: 22.7%, marijuana; 6.7%, cocaine or crack; 9.3%, amphetamines; 3.1%, psychedelics; and 4.3%, heroin. After adjustment for age, race, education, income, smoking, alcohol consumption, systolic blood pressure, use of antihypertensive medications, body mass index, and history of diabetes and dyslipidemia, relative risk for mild kidney function decline associated with any drug use was 2.3 (95% confidence interval, 1.0 to 5.1). After similar adjustments, risks for mild kidney function decline were 3.0 (95% confidence interval, 1.1 to 8.0) and 3.9 (95% confidence interval, 1.1 to 14.4) times greater among persons who had used cocaine and psychedelics, respectively. Use of marijuana, amphetamines, heroin, and other drugs was associated with elevated, but not statistically significant, risks for mild kidney function decline.

CONCLUSION

Our study documented a significant, positive, and independent association between illicit drug use and risk for mild kidney function decline. This finding indicates that interventions aimed at helping patients discontinue illicit drug use and maintain a drug-free lifestyle may have an important role in delaying and/or preventing the onset of kidney disease in hypertensive men.

Cardiovascular manifestations of substance abuse part 1: cocaine

Substance abuse with cocaine is associated with multiple cardiovascular conditions, including myocardial infarction, dissection, left ventricular hypertrophy, arrhythmias, sudden death, and cardiomyopathy. Cocaine has effects to potentiate the physiologic actions of catecholamines and has direct effects on voltage-dependent sodium ion channels related to local anesthetic properties. The effects of cocaine can be augmented with concomitant alcohol consumption. Acute myocardial ischemia caused by cocaine may be related to in situ thromboisis and/or coronary vasospasm. Treatment strategies for cocaine-induced myocardial infarction would include antiplatelet therapy, thrombolysis, and vasodilators (eg, nitrates, nifedipine). Beta-adrenergic blockers should not be used unless concomitant vasodilator therapy is given.

The pathophysiology of cocaine abuse

Cocaine is a naturally occurring alkaloid that increases dopamine concentrations in the reward centers of the brain. There has been a marked increase in cocaine abuse over the last two decades. A neuropsychological stimulant, cocaine also reduces somnolence, increases alertness and improves concentration. However, cocaine abuse has many pathophysiological consequences. These fall broadly into four groups: pathology associated with a drug abusing lifestyle, pathology that occurs whilst intoxicated with (but not directly due to) the drug, pathology associated with drug administration and pathology resulting from pharmacological action of the drug. This review provides a detailed description of the physiological, pharmacological, and pathological effects of cocaine, and highlights the forensic and medicolegal implications of cocaine abuse.

Cardiovascular disorders associated with cocaine use: myths and truths

Cocaine produces a pattern of cardiovascular responses that are associated with apparent myocardial ischemia, arrhythmias, and other life-threatening complications in some individuals. Despite recent efforts to better understand the causes of cocaine-induced cardiovascular dysfunction, there remain a number of unanswered questions regarding the specific mechanisms by which cocaine elicits hemodynamic responses. This review will describe the actions of cocaine on the cardiovascular system and the evidence for the mechanisms by which cocaine elicits hemodynamic and pathologic responses in humans and animals. The emphasis will be on experimental data that provide the basis for our understanding of the mechanisms of cardiovascular toxicity associated with cocaine. More importantly, this review will identify several controversies regarding the causes of cocaine-induced cardiovascular toxicity that as yet are still debated. The evidence supporting these findings will be described. Finally, this review will outline the obvious deficits in our current concepts regarding the cardiovascular actions of cocaine in hope of encouraging additional studies on this grave problem in our society.

Quantitative comparison of coronary artery flow and myocardial perfusion in patients with acute myocardial infarction in the presence and absence of recent cocaine use

BACKGROUND

Numerous factors have been implicated in the pathogenesis of cocaine associated myocardial infarction (CAMI). However, the relative contributions each of these mechanisms provide to the pathogenesis of CAMI have not been well defined. We hypothesized that significant angiographic differences exist between CAMI patients vs thrombotic AMI patients (TAMI) and normal controls.

METHODS

The TIMI Flow Grade, corrected TIMI Frame Count (CTFC), TIMI Myocardial Perfusion Grade (TMPG), presence of triple-vessel disease, stenosis severity, and presence of angiographically apparent thrombus were compared in patients who sustained CAMI to TAMI patients and normal controls.

RESULTS

2495 angiograms were analyzed (CAMI = 57, TAMI = 2403, Controls = 35). Impairment in both epicardial and microvascular flow in patients with CAMI was intermediate between TAMI and controls. Compared to TAMI patients, CAMI patients were less likely to have 3 vessel disease (8.9% vs. 19.1%; p < 0.05), epicardial stenosis was less severe (14.9+/-30.2 vs. 72.6+/-18.6; p < 0.0001), less thrombus was present (6.5% vs. 33.1%; p < 0.001) and TIMI grade 3 flow was observed more frequently (76% vs. 59%). Normal TMPG 3 perfusion was significantly impaired in both CAMI and TAMI patients when compared to controls without AMI (TMPG 3 was 40% and 26.6% vs. 100% respectively; p < 0.001 for both). The majority of patients in both AMI groups had diminished or absent tissue level perfusion (TMPG 0 flow, CAMI 53.9 vs. TAMI 56.8%).

CONCLUSIONS

Both epicardial and microvascular flow is impaired in CAMI. While epicardial flow among CAMI patients is slightly better than TAMI patients, the incidence of little or severely impaired tissue level perfusion is nearly identical.

Diastolic alterations in infants exposed to intrauterine cocaine: a follow-up study by color kinesis

BACKGROUND

During the first 48 hours of life, newborn infants exposed to cocaine in utero have left ventricular diastolic segmental abnormalities. It is unknown whether these abnormalities are transient because of short-term effects or persist in older infants, possibly reflecting a teratogenic effect of cocaine.

METHODS

This study prospectively evaluated global and segmental systolic and diastolic cardiac parameters by color kinesis. The patients were 2- to 6-month-old infants who were exposed to cocaine in utero (N = 56). Their data were compared with normal control patients with no intrauterine drug exposure (N = 60) and newborns exposed to drugs other than cocaine (N = 72).

RESULTS

At the age of 2 to 6 months, there was no significant difference in the measured color kinesis parameters among the cocaine-exposed and the 2 control groups (infants prenatally exposed to other drugs and no drugs). Infants exposed to heavy cocaine prenatally, as compared with the noncocaine-exposed group, had a significant (P =.007) increase in septal fractional area change during left ventricular filling.

CONCLUSIONS

At 2 to 6 months of age, infants have recovered from initial left ventricular diastolic segmental alterations seen in the first 48 hours of life except for the septal wall in the heavily cocaine-exposed group.

Cocaine use and cardiovascular complications

In Australia, the lifetime use of cocaine is rising, with 3% of the population aged over 14 using cocaine in 1991, increasing to 4.5% in 1998, and cocaine use accounting for 10% of all deaths secondary to illicit drug use in 1998. Cocaine is prepared from the leaves of the plant Erythroxylon coca, and is available as cocaine hydrochloride (a water-soluble powder or granule which can be taken orally, intravenously or intranasally) and as "freebase" or "crack" cocaine (heat stable, melting at high temperatures, thus allowing it to be smoked). Acute myocardial infarction (AMI) is the most commonly reported cardiac consequence of cocaine misuse, usually occurring in men who are young, fit and healthy and who have minimal, if any, risk factors for cardiovascular disease. The mechanism by which cocaine induces AMI is largely not understood. Cocaine effect should be seriously considered in any young patient with minimal risk factors for cardiac disease presenting with AMI, dilated cardiomyopathy, myocarditis or cardiac arrhythmias.

Diastolic filling abnormalities by color kinesis in newborns exposed to intrauterine cocaine

Because cocaine crosses the placenta, we prospectively evaluated global and segmental systolic and diastolic cardiac function by color kinesis in clinically asymptomatic newborns who were exposed to cocaine in utero (group 1, n = 82). Their data were compared with normal controls (group 3, n = 87) and newborns exposed to drugs other than cocaine (group 2, n = 108). During left ventricular filling, newborns exposed to cocaine, compared with groups 2 and 3, had significantly (P <.05) higher global fractional area change (%) (76 +/- 10.3 vs 72 +/- 9.4 and 72 +/- 9.1, respectively), regional fractional area changes (%) for the anterior, septal, inferior, and lateral wall, and in the index of asynchrony (at 50% filling 13.2 +/- 5.8 vs 11.3 +/- 4.1 and 11.6 +/- 4.2, respectively). There were no significant differences in systolic function among the 3 groups. Prenatal cocaine exposure in asymptomatic infants leads to higher global and segmental fractional area changes and asynchrony during diastole. The significance and course of these alterations require further investigation.

Effects of cocaine on the coronary arteries

BACKGROUND

A number of studies have documented myocardial ischemia and infarction associated with cocaine use. Mismatch between myocardial oxygen supply and demand from cocaine-induced vasoconstriction and increased myocardial workload are often invoked as the major postulated mechanism by which cocaine induces myocardial ischemia. This article reviews the literature studying the effects produced by cocaine on the coronary arteries to provide insight into the various pathophysiologic mechanisms by which cocaine triggers acute cardiac ischemia or infarction.

METHODS

We reviewed the published literature describing the effects of cocaine on the coronary arteries. A MEDLINE search of English language articles published between 1985 and 2000 was performed. Key words included coronary arteries, coronary vasoconstriction, vasospasm, coronary vasodilation, cardiac vasculature, myocardial ischemia, platelets, thrombosis, and cocaine. Both animal and human studies were included. The bibliographies of identified articles were also explored for additional sources of information.

RESULTS

A recreational dose of cocaine increases the heart rate by approximately 30 beats/min. It also increases the blood pressure by 20/10 mm Hg. These increases are modest, are equivalent to mild exercise, and are not believed to be sufficient to result in myocardial ischemia in the majority of cases. Animal and human studies have documented cocaine-induced early coronary artery vasodilation as shown by a decrease in coronary perfusion pressure ranging from 13% to 68%. This was followed by a more sustained vasoconstriction demonstrated by a decrease in epicardial coronary artery diameter ranging from 5% to 30% with various doses of cocaine by various methods of administration. These changes alone are also an unlikely explanation for cocaine-induced myocardial ischemia. Therefore neither increases in myocardial workload nor hemodynamic changes are sufficient to explain cocaine-induced myocardial ischemia. However, evidence also exists that cocaine activates platelets and promotes thrombosis, resulting in intracoronary thrombus formation. Cocaine may also promote premature and more severe coronary atherosclerosis.

CONCLUSION

The etiology of cocaine-induced myocardial ischemia is complex and is likely to be multifactorial. It appears to be the result of coronary artery vasoconstriction, intracoronary thrombosis, and accelerated atherosclerosis.

Myocardial infarction with normal coronary arteries: the pathologic and clinical perspectives

Myocardial infarction with normal coronary arteries is a syndrome resulting from numerous conditions but the exact cause in a majority of the patients remains unknown. Cigarette smokers and cocaine users are more prone to develop this condition. The possible mechanisms causing myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, intense sympathetic stimulation, non-atherosclerotic coronary diseases, coronary trauma, coronary vasospasm, coronary thrombosis, and endothelial dysfunction. It primarily affects younger individuals, and the clinical presentation is similar to that of myocardial infarction with coronary atherosclerosis. Thrombolytics, aspirin, nitrates, and beta blockers should be instituted as a standard therapy for acute myocardial infarction. Once normal coronary arteries are identified on subsequent angiography, the calcium channel blockers could be added since coronary vasospasm appears to play a major role in the pathophysiology of this condition. The beta blockers should be avoided in cocaine-induced myocardial infarction because the coronary spasm may worsen. In myocardial infarction with normal coronary arteries, complications such as malignant arrhythmia, heart failure, and hypotension are generally less common, and prognosis is usually good. Recurrent infarction, postinfarction angina, heart failure, and sudden cardiac death are rare. Stress electrocardiography and imaging studies are not useful prognostic tests and long-term survival mainly depends on the residual left ventricular function, which is usually good.

Percutaneous transluminal coronary angioplasty and stenting for cocaine-induced acute myocardial infarction: a case report and review

Cocaine-induced myocardial infarction has been well reported. Likewise, there are numerous reports of patients with cocaine-induced myocardial infarction being treated conservatively with nitroglycerin, verapamil, and thrombolytics. However, based on a Medline search from 1977 to 1998 (with the keywords cocaine and angioplasty), there have been no reports in English of cocaine-induced myocardial infarction being treated with catheter-based intervention. We report such a case, as well as review what is known about the pathophysiology of cocaine-induced coronary arteriopathy and myocardial infarction.

Characteristics and prognosis of myocardial infarction in patients with normal coronary arteries

STUDY OBJECTIVES

Myocardial infarction with angiographically normal coronary arteries (MINC) is a life-threatening event with many open questions for physicians and patients. There are little data concerning the prognosis for patients with MINC.

DESIGN

Retrospective follow-up study.

SETTING

Tertiary referral center.

PATIENTS

Patients with MINC were investigated and compared to age- and sex-matched control subjects with myocardial infarction due to coronary artery disease (CAD). The patients were examined clinically using stress exercise and hyperventilation tests. Migraine and Raynaud's symptoms were determined by means of a standardized questionnaire. Serum lipoproteins; the seroprevalence of cytomegalovirus, Helicobacter pylori, and Chlamydia pneumoniae infections; and the most frequent causes of thrombophilia were assessed.

MEASUREMENTS AND RESULTS

From > 4,300 angiographies that were performed between 1989 and 1996, 21 patients with MINC were identified. The mean +/- SD patient age at the time of myocardial infarction was 42 +/- 7.5 years. When compared to control subjects (n = 21), patients with MINC had fewer risk factors for CAD. In contrast, MINC patients had more frequent febrile reactions prior to myocardial infarction (six patients vs zero patients; p < 0.05), and the migraine score was significantly higher (7.1 +/- 6.3 vs 2.2 +/- 4.1; p < 0.01). The seroprevalence of antibodies against cytomegalovirus, C pneumoniae, and H pylori tended to be higher in patients with MINC and CAD as compared to matched healthy control subjects. Three patients with MINC vs none with CAD had coagulopathy. During follow-up (53 +/- 37 months), no major cardiac event occurred in the MINC group; no patients with MINC vs nine with CAD (p = 0.0001) underwent repeated angiography.

CONCLUSION

High migraine score and prior febrile infection together with a lower cardiovascular risk profile are compatible with an inflammatory and a vasomotor component in the pathophysiology of the acute coronary event in MINC patients. The prognosis for these patients is excellent.

Role of the vascular endothelium in patients with angina pectoris or acute myocardial infarction with normal coronary arteries

Chest pain with normal coronary angiograms is a relatively common syndrome. The mode of presentation of this syndrome includes patients with syndrome X and patients with an acute myocardial infarction and angiographically normal coronary arteries. Different mechanisms have been proposed to elucidate the exact cause and to explain the various clinical presentations in these patients. Abnormalities of pain perception and the presence of oesophageal dysmotility have all been reported in patients with syndrome X. In situ thrombosis or embolization with subsequent clot lysis and recanalization, coronary artery spasm, cocaine abuse, and viral myocarditis have been described as potential mechanisms responsible for an acute myocardial infarction in patients with angiographically normal coronary arteries. Recent data suggest that both microvascular and epicardial endothelial dysfunction may play an important role in the pathophysiological mechanism of the syndrome of stable angina or acute myocardial infarction with normal coronary arteries.

Prolonged perioperative myocardial ischemia in a young male: due to topical intranasal cocaine?

We present a case of prolonged myocardial ischemia in a young healthy male presenting for nasal polypectomy and tonsillectomy. Induction of anesthesia proceeded uneventfully. Immediately after surgical incision, the patient developed a sinus tachycardia with ST-segment depression in leads II and III, and ST elevation in leads aVR, aVL, aVF, and V. Depth of anesthesia was increased, esmolol was administered, which slowed the heart rate, and the procedure was terminated. However, myocardial ischemia only gradually resolved, leaving residual T-wave flattening in lead III by day 3 postoperatively. After extensive investigation to rule out other causes of ischemia, we considered cardiotoxicity due to intranasally administered cocaine with epinephrine to be the most likely precipitant. Nasal packing with gauze soaked in a solution containing cocaine 3 mg/kg and epinephrine 1 mg occurred just 40 minutes prior to induction of anesthesia. Topical intranasal cocaine is rapidly and reliably absorbed systemically, with peak plasma concentrations occurring within 30 to 60 minutes, corresponding to the time course of cocaine administration and surgical stimulation in this patient. Systemic absorption of topical intranasal cocaine has previously been reported to cause adverse cardiac sequelae, including myocardial infarction. This report reinforces the need for caution regarding the use of topical intranasal cocaine, particularly if used in combination with epinephrine.

Triggering of myocardial infarction by cocaine

BACKGROUND

Cocaine has been implicated as a trigger of acute myocardial infarction in patients with and those without underlying coronary atherosclerosis. However, the magnitude of the increase in risk of acute myocardial infarction immediately after cocaine use remains unknown.

METHODS AND RESULTS

In the Determinants of Myocardial Infarction Onset Study, we interviewed 3946 patients (1282 women) with acute myocardial infarction an average of 4 days after infarction onset. Data were collected on the use of cocaine and other potential triggers of myocardial infarction. We compared the reported use of cocaine in the hour preceding the onset of myocardial infarction symptoms with its expected frequency by using self-matched control data based on the case-crossover study design. Of the 3946 patients interviewed, 38 (1%) reported cocaine use in the prior year and 9 reported use within the 60 minutes preceding the onset of infarction symptoms. Compared with nonusers, cocaine users were more likely to be male (87% vs 67%, P=0.01), current cigarette smokers (84% vs 32%, P<0.001), younger (44+/-8 vs 61+/-13 years, P<0.001), and minority group members (63% vs 11%, P<0.001). The risk of myocardial infarction onset was elevated 23.7 times over baseline (95% CI 8.5 to 66.3) in the 60 minutes after cocaine use. The elevated risk rapidly decreased thereafter.

CONCLUSIONS

Cocaine use is associated with a large abrupt and transient increase in the risk of acute myocardial infarction in patients who are otherwise at relatively low risk. This finding suggests that studying the pathophysiological changes produced by cocaine may provide insights into the mechanisms by which myocardial infarction is triggered by other stressors.

Cardiotoxic mechanisms and interrelationships of cocaine: including a single case depicting several of these mechanisms

The underlying mechanisms of myocardial infarction as a result of cocaine abuse appear to be multifactorial. The various cardiotoxic mechanisms and interrelationships of cocaine are fully reviewed, and a chart has been reconstructed to give the reader a clearer understanding of them. Moreover, an unusual case of a 29-year-old male cocaine abuser is presented because it illustrates many of the reported cardiotoxic effects, all of which are present in the same individual.

Cocaine-induced thrombosis of common iliac and popliteal arteries

Cocaine-induced thrombosis has been reported in the literature; however, its mechanism is not fully understood. Most cases are of small caliber vessels, such as the coronaries and cerebral vasculature. We report a case of a 36-year-old man with signs and symptoms of acute arterial insufficiency in his right lower extremity. At angiography, the right common iliac artery and the popliteal artery were occluded. The patient was successfully treated with thrombolytic therapy. Cocaine-induced thrombosis should be suspected in a patient with history of cocaine abuse who presents with acute arterial insufficiency in an extremity, without an identifiable source.

Cocaine increases the endothelial release of immunoreactive endothelin and its concentrations in human plasma and urine: reversal by coincubation with sigma-receptor antagonists

BACKGROUND

Cocaine-associated vascular events are not completely explained by adrenergic stimulation. The purposes of this study were to investigate whether vasoconstrictive endothelin-1 is released by cocaine and to elucidate the mechanisms involved.

METHODS AND RESULTS

Endothelin-1 was measured by radioimmunoassay and high-performance liquid chromatography (1) in the supernatant of porcine aortic endothelial cells after treatment with cocaine (10(-7) to 10(-4) mol/L) and a sigma-receptor antagonist, haloperidol (10(-6) mol/L) or ditolylguanidine (10(-5) mol/L) and (2) in plasma and urine of 12 cocaine-intoxicated patients and 13 healthy control subjects. Radioligand binding assays were performed on endothelial membrane preparations. In cell culture, cocaine significantly increased endothelin accumulation above baseline at 3 to 24 hours; endothelin release rates per hour increased dose-dependently, reaching a plateau of 175+/-23% of control at hour 4 to 5. Coincubation of cocaine with haloperidol or ditolylguanidine abolished or reduced cocaine-induced endothelin release. Endothelial membrane preparations specifically and displaceably bound the highly selective sigma-ligand [3H]ditolylguanidine (25x10(-9) mol/L), with 1400 binding sites estimated per cell. Endothelin-1 levels in plasma (22.7+/-5.6 versus 7.3+/-0.8 pmol/L) and urine (41.5+/-10.1 versus 12.7+/-3.8 pmol/L) of cocaine-intoxicated patients were significantly increased compared with control values.

CONCLUSIONS

The data suggest that cocaine increases the endothelin-1 release in vitro and in vivo. The cocaine-induced vasoconstriction/vasospasm may therefore be facilitated by the release of endothelin-1. Cocaine appears to be an exogenous stimulator at endothelial sigma-receptors. The endogenous ligands of this antiopioid system may prove to play a role in vasospastic angina, acute myocardial infarction, and sudden cardiac death.

Acute deleterious effects of cocaine on cardiac conduction, hemodynamics, and ventricular fibrillation threshold: effects of interaction with a selective dopamine D1 antagonist SCH 39166

Cocaine has demonstrated cardiotoxicity that has led to sudden death by unknown mechanisms. SCH 39166, a selective dopaminergic D1-receptor antagonist, suppresses the compulsive drug-intake actions of cocaine in primates. This study examined the cumulative toxic effects of cocaine after the long-term administration of SCH 39166. After pretreatment with oral placebo/SCH 39166 for 5 days, an i.v. infusion of 0.25 mg/kg/min of cocaine HCl was delivered to 14 anesthetized dogs, and cardiac conduction, arterial blood pressure, ventricular refractoriness, and arrhythmogenesis were examined. The cocaine infusion was stopped when QRS width increased by 20% from baseline (QRS20). In Coc + Placebo regimen, the QRS and His-Ventricular (HV) intervals showed a dose-dependent lengthening. Initially, the mean blood pressure (MBP) increased followed by a precipitate decrease at a mean dose of 2.03 +/- 0.5 mg/kg of cocaine. At QRS20, the ventricular effective refractory period (ERP) increased significantly, whereas the ventricular fibrillation threshold (VFT) showed a significant reduction from the baseline. In Coc + SCH, the QRS, HV intervals, and ERP increased similarly, but the decrease in MBP was attenuated, and the VFT was increased. A relatively small infusion of cocaine causes a hemodynamic compromise. The His-ventricular conduction delay and lengthened ERP suggest a predominant direct local anesthetic effect. Cocaine additionally decreased the VFT, suggesting an increased susceptibility to VF. SCH 39166 did not potentiate the cardiotoxic effects of cocaine. It displayed a protective trend by suppressing the arrhythmogenic effects and the hemodynamic compromise caused by cocaine.