Smoking Cessation and Functional CT Assessment

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 your 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 your 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.

Inclusion Criteria:

- Between the age of 25 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.

Exclusion Criteria:

- Women only: Cannot be pregnant or nursing at baseline or plan to become pregnant
during the course of the study

- Body Mass Index (BMI) > 32

- Weight > 220 pounds

- 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