E-Cigarette Aerosol, Conventional Cigarette Smoke, and Myocardial Perfusion

Study Overview
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Brief Summary
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E-cigarettes deliver nicotine by creating an aerosol of ultrafine particles. Many questions remain about the size and composition and especially about the potential toxicity of these particles. Thus, a key unanswered question-and the research question proposed-is whether e-cigarette aerosol triggers the same acute impairment in coronary microvessel function as does conventional cigarette smoke, which delivers a very well-defined exposure to fine particles and many fold greater exposure to toxic (combustion) products including volatile organic compounds (such as acrolein) that have been implicated in the pathogenesis of tobacco-related coronary disease. Because the effects of nicotine on the human coronary microcirculation remain incompletely defined-with multiple potential vasodilator and vasoconstrictor actions each of which may vary by dose-we will determine the comparative effects of conventional cigarette smoke against e-cigarette aerosol with no nicotine, with low-dose nicotine, and with high-dose nicotine.

Official Title
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E-Cigarette Aerosol, Conventional Cigarette Smoke, and Myocardial Perfusion

Conditions
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Coronary Artery Disease, Myocardial Perfusion

Intervention / Treatment
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* Other: Cigarettes
* Other: E-cigarettes (nicotine free e-liquid)
* Other: E-cigarettes (low nicotine e-liquid)
* Other: E-cigarettes (high nicotine e-liquid)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-49 Regular cigarette smoker defined as at least 1 pack year and ≥ 5/day E-cigarette smoker defined as ≥ 1/week in the last 6 months. Exclusion Criteria: Sub-optimal echocardiography images as determined by the sonographer and/or investigators. History of cardiopulmonary (including asthma or use of inhalers), History of diabetes or dyslipidemia History of psychiatric illness Blood Pressure > 140/90 Body Mass Index ≤ 18.5 or ≥ 30 kg•m2 Evidence of any of the above by physical examination, Electrocardiogram (ECG) or echocardiogram Resting Heart Rate > 100 beats/min Cardiac rhythm disorder, specifically: rhythm other than sinus, Supraventricular Tachycardia (SVT), atrial fibrillation, ventricular tachycardia Use of prescription medication except oral contraceptive pills History of illicit drug use (self-stated) Pregnant Any other condition(s) deemed by the physician investigators that put subjects at risk for participating in the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 49 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cigarettes<br>Healthy chronic dual cigarette and e-cigarette smokers will undergo myocardial contrast echocardiography before and after smoking two standard cigarettes | Other: Cigarettes<br>* Subjects will smoke a standard cigarette (yield: tar 12 mg, nicotine 1 mg)<br>|
| Experimental: E-cigarettes (nicotine free e-liquid)<br>Healthy chronic dual cigarette and e-cigarette smokers will undergo myocardial contrast echocardiography before and after smoking nicotine free e-cigarette liquid. | Other: E-cigarettes (nicotine free e-liquid)<br>* Subjects will smoke nicotine free e-liquid with an e-cigarette.<br>|
| Experimental: E-cigarettes (low nicotine e-liquid)<br>Healthy chronic dual cigarette and e-cigarette smokers will undergo myocardial contrast echocardiography before and after smoking low concentration(4-6 mg/mL) e-cigarette liquid. | Other: E-cigarettes (low nicotine e-liquid)<br>* Subjects will smoke low nicotine (4-6 mg/mL) e-liquid with an e-cigarette.<br>|
| Experimental: E-cigarettes (high nicotine e-liquid)<br>Healthy chronic dual cigarette and e-cigarette smokers will undergo myocardial contrast echocardiography before and after smoking high concentration (18-24 mg/mL) e-cigarette liquid. | Other: E-cigarettes (high nicotine e-liquid)<br>* Subjects will smoke low nicotine (18-24 mg/mL) e-liquid with an e-cigarette.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial Perfusion (change in microvascular flux rate from baseline at 30 minutes) | Myocardial contrast echocardiography will be used to measure regional myocardial perfusion - microvascular flux rate | Baseline and 30 minutes after smoking | 
| Myocardial Perfusion (change in capillary blood volume from baseline at 30 minutes) | Myocardial contrast echocardiography will be used to measure regional myocardial perfusion - capillary blood volume | Baseline and 30 minutes after smoking | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Myocardial perfusion, Electronic cigarettes, Cigarettes, Cigarette smoking