Is cocaine use recognised as a risk factor for acute coronary syndrome by doctors in the UK?

A Role of Thyroid Hormones in Acute Myocardial Infarction: An Update

The acute coronary syndrome is one of the commonest life-threatening illnesses. It encompasses the clinical spectrum of acute myocardial ischemia and includes unstable angina and acute myocardial infarction both with and without ST segment elevation. The acute coronary syndrome can be attributed to a significant hemodynamic insult that leads to atherosclerosis of the epicardial coronary arteries. The main causative risk factors, such as obesity, smoking, and alcohol intake, increase the burden of acute coronary syndrome. Owing to an increase in the utilization of antioxidants, the antioxidant capacity decreases concerning the scavenging of lipid peroxides. Moreover, the thyroid hormones are important regulators of the expression of cardiac genes, and many of the cardiac manifestations of thyroid dysfunction are associated with alterations in triiodothyronine- mediated gene expression. Cardiovascular signs and symptoms of thyroid disease are among the most acute clinically relevant findings that occur in combination with both hypothyroidism and hyperthyroidism. By understanding the cellular mechanism of the action of thyroid hormones on the heart and cardiovascular system, it is possible to explain rhythm disturbances and alterations in cardiac output, blood pressure, cardiac contractility, and vascular resistance that result from thyroid dysfunction. Oxidative stress is thereby induced, together with a decrease in antioxidant capacity for overcoming oxidative stress, which leads to endothelial dysfunction, subsequent atherosclerosis, and, ultimately, acute myocardial infarction. The implications for the identification of the effects of thyroid disease on acute myocardial infarction include the observation that restoration of normal thyroid function repeatedly reverses abnormalities in cardiovascular hemodynamics.

Putting cocaine use and cocaine-associated cardiac arrhythmias into epidemiological and clinical perspective

This is the first article in a series of three articles on cocaine-related cardiac arrhythmias, following on from the 2008 British Pharmacological Society Winter Meeting Clinical Section Symposium entitled 'Cocaine induced cardiac arrhythmias - from ion channel to clinical treatment'. We will summarize the epidemiology of cocaine use across the world and in particular will focus on UK, Europe and US use prevalence data. We will discuss the acute cardiac and non-cardiac toxicity associated with cocaine and highlight the lack of data on the true UK prevalence of acute cocaine toxicity and on the incidence of cocaine-related cardiac arrhythmias.

Prevalence, clinical characteristics and risk of myocardial infarction in patients with cocaine-related chest pain

INTRODUCTION AND OBJECTIVES

To investigate the frequency of recent cocaine use in patients attending an emergency department for acute chest pain, to describe the clinical characteristics of these patients, and to estimate the incidence of acute coronary syndrome in this population.

METHODS

Observational cohort study using a standard questionnaire that includes items on recent cocaine consumption.

RESULTS

During a 1-year period, 1240 patients aged under 55 years presented with chest pain. Of these, 63 (5%) had cocaine-related chest pain (7% of men and 1.8% of women). These patients were younger (35+/-10 years vs. 39+/-10 years; P=.002), were more frequently male (87% vs. 62%; P< .001), and were more frequently smokers (59% vs. 35%; P< .001). Patients who had used cocaine recently had a higher incidence of acute myocardial infarction (16 vs. 4%; P< .001), especially ST-segment-elevation myocardial infarction (11.1% vs. 1.6%; P< .01). After adjusting for coronary risk factors, history of cardiovascular disease and previous treatment, the odds ratio for myocardial infarction with recent cocaine consumption was 4.3 (95% confidence interval, 2-9.4).

CONCLUSIONS

Cocaine-related chest pain is often encountered in emergency departments, especially in men aged under 55 years. It is associated with a four-fold increase in the risk of acute myocardial infarction. All male patients aged under 55 years with acute chest pain should be asked about cocaine use.

Undisclosed cocaine use and chest pain in emergency departments of Spain

Aims

Illicit cocaine consumption in Spain is one of the highest in Europe. Our objective was to study the incidence of undisclosed cocaine consumption in patients attending in two Spanish Emergency Departments for chest pain.

Methods

We analysed urine samples from consenting consecutive patients attending ED for chest pain to determine the presence of cocaine, and other drugs, by semiquantative tests with fluorescence polarization immunoassay (FPIA).

Results

Of 140 cases, 15.7 presented positive test for drugs, and cocaine was present in 6.4%. All cocaine-positive patients were younger (p < 0.001); none was admitted to Hospital (p = 0.08). No significant differences in ED stay or need for hospitalization were found between cocaine-positive and negative patients.

Conclusion

This finding in chest pain patients who consented to urine analysis suggests that the true incidence of cocaine use leading to such ED visits may be higher.