This study uses CT scans to visualize the heart and surrounding arteries to look for coronary artery disease. This study takes into account individuals body type including size, weight, and heart rate to tailor the CT scan and contrast media given to each patient. Taking into account each patients body will allow doctors to obtain the best image possible while reducing the amount of contrast media given to patients.

This study evaluates whether non-cigarette tobacco products (e-cigarettes) can help smokers quit smoking as compared to traditional quit methods (nicotine replacement therapy or varenicline/Chantix). Participants in this study will be randomly assigned to one of two groups, then will have a choice between the offered products of that group. Participants in the e-cigarette group will have a choice of e-cigarette brand and flavor. Participants in the medication group will have choice between nicotine replacement therapy (patches and lozenges) or varenicline, also known as Chantix. Participation will last 6 months and will include weekly phone calls for the initial 7-weeks plus a 11-week phone call and a 6-month follow-up visit. Participants will also complete electronic daily diaries during the first 7-weeks.