1. Cardiovascular Complications of Cocaine Abuse
Payal Nanda
Scotty Gadlin
Ken Arney
(aka Night Floaticians)

3. Introduction
Cocaine is the 2nd most commonly used illicit drug in the U.S.
In 2005, there were ~450,000 cocaine-related ED visits with 40% due to chest pain.
Even casual use of cocaine is associated with cardiovascular toxicity.
Cocaine use is associated with acute more often than chronic cardiovascular illness.
Cocaine users can present with ACS, arrhythmias, myocarditis, aortic dissection and rupture, and hypertensive emergency.
Therefore, identifying cocaine exposure is an important part of cardiovascular history-taking.

4. Cardiovascular Effects of Cocaine
The major cardiovascular effects of cocaine are caused by inhibition of norepinephrine/dopamine reuptake into the synaptic cleft by sympathetic neurons.
This inhibition results in potentiation of the response to sympathetic stimulation of innervated organs, causing a powerful sympathomimetic response.
Also enhances the release of catecholamines from central and peripheral stores.
Cocaine also promotes thrombus formation via activation of platelets and stimulation of platelet aggregability.

5. Cardiovascular Conditions Associated with Cocaine Use
Myocardial ischemia/infarction
Cardiomyopathy
Myocarditis
Arrhythmias
Stroke
Aortic dissection
Coronary artery aneurysms

6. Myocardial Ischemia
Most common complication; associated with all routes of cocaine intake
Three proposed mechanisms:
Increased myocardial oxygen demand
Resulting from sympathomimetic actions of cocaine that increase myocardial inotropy, heart rate, and BP in dose-dependent manner
Exacerbated by underlying CAD (e.g. fixed stenoses)
Coronary vasoconstriction and spasm  decreased oxygen
Cocaine constricts coronary vessels via stimulation of alpha-adrenergic receptors, increased endothelin-1, and decreased NO
Coronary thrombosis
Platelet activation/aggregation and premature atherosclerosis
Most patients have no other cardiac risk factors

7. Myocardial Infarction
Incidence of MI in cocaine-related chest pain is %
Increased incidence in younger patients
NHANES III study: 25% of nonfatal MIs were between ages of 18-45
MI is temporally related to cocaine use; two thirds of cases occur within 3 hours.
Most MIs occur in absence of high-grade atherosclerotic coronary stenoses.
Complications post-MI include heart failure and ventricular/supraventricular arrhythmias, typically occurring within first 12 hours (same as in non-cocaine induced infarctions).

8. Relative Risk of MI Onset After Cocaine Use

9. Cardiomyopathy Dilated CM is well-documented among cocaine users.
Pathogenesis:
Direct toxic effects on the heart, which lead to the destruction of myofibrils, interstitial fibrosis, myocardial dilation, and heart failure
Hyperadrenergic state may produce contraction band necrosis in the heart
Myocarditis and CM may be caused by infectious agents in patients who abuse cocaine parenterally via direct invasion of myocardium or stimulation of an autoimmune reaction
Abstinence usually leads to complete reversal of myocardial dysfunction.

10. Arrhythmias
Hyperadrenergic state can produce or exacerbate arrhythmias.
Cocaine acts like a class I anti-arrhythmic agent, producing local anesthetic effects via sodium channel blockade in the heart.
Sinus tachycardia/bradycardia
Bundle branch block
Vfib/Vtach/asystole
Accelerated idioventricular rhythms
SVTs
Torsades de pointe
Brugada pattern on EKG
Rhythm disturbances are transient and disappear when the drug is metabolized.

11. Stroke
Cocaine use significantly increases the risk of ischemic stroke via vasospasm from dopamine release, thrombus formation, and changes in cerebral vasculature (vasculitis).
Subtle and severe neurologic deficits can occur
Repetitive ischemic insults can lead to intracerebral and subarachnoid hemorrhage

12. Diagnosis Hx and physical exam:
Young patient with hx of cocaine or polysubstance abuse who presents with chest pain, dyspnea, palpitations, agitation, or nausea
Usually no other cardiac risk factors
Toxicology screen
EKG: STEMI, T-wave changes, arrhythmias, LVH, LAD
Difficult to interpret in young patients who have a relatively high incidence of early repolarization changes and left ventricular hypertrophy.
Up to 43% of cocaine abusers without an MI may have ST segment elevation ≥0.1 mV in two or more contiguous ECG leads.
Because of the difficulty in identifying cocaine users with chest pain who are at low risk of infarction, most are admitted to the hospital.
Serum markers: Troponins and CK-MB most sensitive and specific in cocaine-related MI

13. Management
There are no well-designed, randomized, prospective clinical trials to compare treatment strategies for cocaine-associated myocardial ischemia

14. The Beta-Blocker Controversy
Beta Blockers for Chest Pain Associated With Recent Cocaine Use
Rangel, et.al. Archives of Internal Medicine 2010.
Retrospective study of consecutive patients admitted to San Francisco General Hospital between
Chest pain and urine toxicology positive for cocaine
The primary predictor was receipt of a B-blocker in the ED, and the primary outcome was death.
Treatment of chest pain in the setting of recent cocaine use was not dictated by any established protocol, and B-blocker use was determined by the discretion of the treating physicians.
151 patients received B-blockers; IV metoprolol in 113 (74%), oral metoprolol in 17 (11%); the rest received labetalol, atenolol, or propranolol.
There were no meaningful differences in EKG changes, troponin levels, length of stay, use of vasopressor agents, intubation, ventricular tachycardia/ventricular fibrillation, or death between those who did and did not receive a B-blocker.
B-Blockers did not appear to be associated with adverse events in patients with chest pain with recent cocaine use.
Over a median follow-up of 972 days, patients discharged on a beta-blocker regimen exhibited a significant reduction in cardiovascular death.

15. Outcomes with Beta-Blockers in Cocaine-Associated Chest Pain

16. Where the Crack At?

17. References
McCord, et.al. Management of Cocaine-Associated Chest Pain and Myocardial Infarction: A Scientific Statement From the American Heart Association Acute Cardiac Care Committee of the Council Clinical Cardiology. Circulation 2008.
Rangel, et.al. Beta-blockers for Chest Pain Associated with Recent Cocaine Use. Arch Intern Med (10):
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