Smoking Cessation and Functional CT Assessment

Study Overview
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Brief Summary
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The investigators will study the effect of pulmonary arterial vasodilation to see if it eliminates indices of persistent lung injury in smokers that are susceptible to emphysema.

Detailed Description
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The purpose of this research study is to find out if smoking cessation combined with sildenafil, an FDA approved drug for pulmonary hypertension, will decrease inflammation in the lung. Even if a smoker stops smoking, the harmful effects caused by previous smoking may recruit inflammatory cells to those affected areas, leading to lung injury. In about 30-40% of smokers, this inflammation combined with irregular blood flow in the lungs may lead to emphysema. The study goal is to measure and compare individual responses to smoking cessation, Sildenafil and placebo used three times per day, and imaging of the lungs using non-contrast and contrast CT scans to see if there is a possible decrease of inflammation and an increase of blood flow in the lungs. The study also intends to see if using Sildenafil three times per day, in addition to smoking cessation will restore blood flow to the possible injured areas of the lungs. Sildenafil is an FDA approved medication for pulmonary hypertension but will be used off-label to study the effects it may or may not have on the blood flow in possible injured areas of the lungs. Non-smokers will be enrolled to compare lung imaging and the effects of Sildenafil on their lungs with that of smokers undergoing a smoking cessation program with placebo or Sildenafil. Non-smokers will complete identical measurements as smokers, with Sildenafil used three times per day or no medication across a similar 90 day period of time. Vascular measurements of pulse wave velocity, carotid artery compliance/stiffness and pressure wave reflection will be done at baseline and 90 day visits.

Official Title
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Smoking Cessation and Functional CT Assessment of Pulmonary Arterial Dysfunction in Smoking Associated Emphysema

Conditions
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Emphysema

Intervention / Treatment
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* Drug: Sildenafil 20 MG
* Drug: Placebo Oral Tablet
* Diagnostic Test: Pulse wave velocity
* Diagnostic Test: Carotid artery compliance and stiffness
* Diagnostic Test: Pressure wave reflection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria (Smokers): Between the age of 21 to 65 at baseline Be willing to participate in a smoking cessation program Be willing to attend all clinic visits Must be currently smoking at least ½ pack/day at baseline (confirmed with cotinine level and CO Smokerlyzer) >5 pack-year history of smoking Global Initiative for Chronic Obstructive Lung Disease (GOLD) 0: FEV1≥0.80 and FEV1/FVC>0.70 Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC) GOLD 1: FEV1≥0.80 and FEV1/FVC < 0.70 GOLD 2: 0.50≤FEV1<0.80 and FEV1/FVC < 0.70 Be willing to abstain from using any nicotine patches, e-cigarettes, or marijuana for the duration of the study. Inclusion Criteria (Non-smokers): Between the age of 21 to 65 at baseline Be willing to attend all clinic visits Have never smoked (confirmed with cotinine level and CO smokerlyzer) GOLD 0: FEV1≥0.80 and FEV1/FVC>0.70 Exclusion Criteria (Smokers and Non-smokers): Women only: Cannot be pregnant or nursing at baseline or plan to become pregnant during the course of the study Body Mass Index (BMI) > 35 Allergies to shell fish, seafood, eggs or iodine Heart disease, kidney disease or diabetes Diagnosis of asthma Any metal in or on the body (that cannot be removed) between the nose and the abdomen Any major organ system disease (by judgment of the study medical team) A glomerular filtration rate of 60 cc per minute or less. Nitroglycerin usage or nitrates and use of phosphodiesterase 5 (PDE5) inhibitors Prior history of hypersensitivity to sildenafil Currently prescribed a phosphodiesterase (PDE) inhibitors medication (ex: Viagra, Cialis, etc) Known Pulmonary Hypertension Has used e-cigarettes and marijuana <1 years Use of ACE Inhibitors, Calcium Channel Blockers, Angiotensin II Receptor Blockers for control of blood pressure or any combination of these three types of medications.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 65 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Smoking Cessation Group 1<br>80 normal smokers will be recruited (defined by Pulmonary Function Tests, questionnaires and interviews), between the ages of 21 and 65 will be studied to assess inflammation and heterogeneity of Perfused Blood Volume prior to and following a 3 month smoking cessation program. In 40 of the 80 subjects during the smoking cessation program, we will provide three times per day Sildenafil 20 milligrams (MG) (Viagra) for the full 3 months of the smoking cessation period. We select a three-month cessation program to maximize the likelihood of compliance with cessation yet providing enough time for a resolution of lung injury to take place. Pulse wave velocity, carotid artery compliance and stiffness and pressure wave reflection will be measured. | Drug: Sildenafil 20 MG<br>* Sildenafil, 20mg three times daily for 3 month period.<br>* Other names: Experimental: Non-Smokers Group 1;Diagnostic Test: Pulse wave velocity<br>* Vascular pulse measurement at the radial, brachial, femoral, and carotid arteries are taken using a tonometer probe.<br>Diagnostic Test: Carotid artery compliance and stiffness<br>* An echocardiogram is done by using a probe placed on the skin.<br>Diagnostic Test: Pressure wave reflection<br>* Carotid pulse measurement taken using a tonometer probe<br>|
| Placebo Comparator: Smoking Cessation Group 2<br>80 normal smokers will be recruited (defined by Pulmonary Function Tests, questionnaires and interviews), between the ages of 21 and 65 will be studied to assess inflammation and heterogeneity of Perfused Blood Volume prior to and following a 3 month smoking cessation program. In 40 of the 80 subjects during the smoking cessation program, we will provide three times per day placebo oral tablet for the full 3 months of the smoking cessation period. We select a three-month cessation program to maximize the likelihood of compliance with cessation yet providing enough time for a resolution of lung injury to take place. Pulse wave velocity, carotid artery compliance and stiffness and pressure wave reflection will be measured. | Drug: Placebo Oral Tablet<br>* Placebo manufactured to look like Sildenafil 20 MG<br>* Other names: No Intervention: Smoking Cessation Group 2;Diagnostic Test: Pulse wave velocity<br>* Vascular pulse measurement at the radial, brachial, femoral, and carotid arteries are taken using a tonometer probe.<br>Diagnostic Test: Carotid artery compliance and stiffness<br>* An echocardiogram is done by using a probe placed on the skin.<br>Diagnostic Test: Pressure wave reflection<br>* Carotid pulse measurement taken using a tonometer probe<br>|
| Experimental: Non-Smokers Group 1<br>20 non-smokers will be recruited (defined by Pulmonary Function Tests, questionnaires and interviews) between the ages of 21 and 65 will be studied to compare the heterogeneity of Perfused Blood Volume with that of smokers for a 3 month period of time. We will provide 10 females and 10 males three times per day Sildenafil 20 milligrams (MG) (Viagra) for the full 3 months. | Drug: Sildenafil 20 MG<br>* Sildenafil, 20mg three times daily for 3 month period.<br>* Other names: Experimental: Non-Smokers Group 1;Diagnostic Test: Pulse wave velocity<br>* Vascular pulse measurement at the radial, brachial, femoral, and carotid arteries are taken using a tonometer probe.<br>Diagnostic Test: Carotid artery compliance and stiffness<br>* An echocardiogram is done by using a probe placed on the skin.<br>|
| No Intervention: Non-Smokers Group 2<br>20 non-smokers will be recruited (defined by Pulmonary Function Tests, questionnaires and interviews) between the ages of 21 and 65 will be studied to compare the heterogeneity of Perfused Blood Volume with that of smokers for a 3 month period of time. 10 females and 10 males will not receive any medication for the full 3 months. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measure and compare individual smokers' responses to smoking cessation, Sildenafil and placebo with lung imaging to determine decrease of inflammation and increase of blood flow in lungs. | Our outcome measure is the change in regional blood volume between baseline and interventions with CT imaging, sildenafil/placebo and smoking cessation. | 90 Days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulse wave velocity of carotid radial, brachial, femoral and carotid arteries | Our outcome measure is the difference of arterial stiffness between baseline and 90 day visits. | Baseline and 90 day | 
| Carotid beta-stiffness index | Our outcome measure is the difference of common carotid artery stiffness between baseline and 90 day visits | Baseline and 90 Day | 
| Carotid augmentation index | Our outcome measure is the difference of pressure wave reflection between baseline and 90 day visits | Baseline and 90 Day |