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

Cedars-Sinai Medical Center20 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Enrollment

Conditions

Coronary Artery Disease Myocardial Perfusion

CigarettesOTHER

Subjects will smoke a standard cigarette (yield: tar 12 mg, nicotine 1 mg)

E-cigarettes (nicotine free e-liquid)OTHER

Subjects will smoke nicotine free e-liquid with an e-cigarette.

E-cigarettes (low nicotine e-liquid)OTHER

Subjects will smoke low nicotine (4-6 mg/mL) e-liquid with an e-cigarette.

E-cigarettes (high nicotine e-liquid)OTHER

Subjects will smoke low nicotine (18-24 mg/mL) e-liquid with an e-cigarette.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 49 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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

Time frame: 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