Losartan for Cardiovascular Issues from Secondhand Smoke

Inclusion Criteria: * Must be able to understand and provide informed consent. * Adults \>= 40 years of age. * Must have a history of occupational exposure to secondhand tobacco smoke for at least 5 years such as flight attendants who worked for airlines before the smoking ban on aircrafts went into effect or casino workers who worked at casinos with no smoke-free policies. * Must have never smoked or have a remote history of light smoking defined as follows: * Lifetime smoking history equivalent to \< 1 pack-year and * No smoking history for \>= 20 years at the time of enrollment. Exclusion Criteria: * Inability or unwillingness of a participant to give written informed consent or comply with study protocol. * Subject is pregnant, breast-feeding, or plans to become pregnant. * Current therapy with angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). * Known intolerance to ACE inhibitor or ARB. * History of angioedema. * Conventional indication for ACE inhibitor or ARB (e.g., history of myocardial infarction, known cardiomyopathy). * Blood pressure less than 90 mm Hg systolic or 60 mm Hg diastolic while standing or sitting. * Known unilateral or bilateral renal artery stenosis higher than 70%. * Renal insufficiency (Creatinine Clearance \<30 mL/min by Cockcroft-Gault calculation). * Current regular use of NSAIDs defined as daily use on 5 or more days of the week for more than one month. * Potassium supplementation or serum potassium level of 5.0 milliequivalents (mEq)/dL or higher at V1. * Current use of a potassium sparing diuretic. * History of clinically overt cardiovascular disease including: stable or unstable angina; chest discomfort and dyspnea with baseline exertion; symptomatic coronary artery disease (as defined by history of abnormal stress test; cardiac catheterization showing \>70% coronary artery stenosis; history of revascularization; pathologic Q waves on EKG); poorly controlled resting hypertension (SBP\>160/ DBP\>95); congestive heart failure (CHF) (as defined by left ventricular ejection fraction (LVEF) \<55%; physical exam findings of CHF; symptomatic pulmonary edema); significant (\>mild) valvular heart disease; congenital heart disease; cardiac arrhythmias including frequent premature atrial or ventricular contractions (\>5 per minute). * History of clinically overt pulmonary disease that may interfere with study procedures, including: greater than mild asthma, COPD, emphysema, chronic interstitial lung disease, and pulmonary hypertension. * Neuromuscular disorders or physical disability to perform exercise testing using an ergometer. * Significant history of recreational drug use other than marijuana as defined by: recreational drug use within the last 30 years of recruitment (or) recreational drug use at a frequency of more than once a month before 30 years. * Marijuana use more than once a week. * Other uncontrolled chronic illnesses which in the judgment of the study physician would interfere with completing study procedures. * Failure to keep screening appointments or other indicators of non-adherence. * Concomitant participation in another interventional study. * Subjects with BMI \<15 or \>40 kg/m2. * MRI Scan Participation Exclusion Criteria - The participants will be excluded from the MRI portion of the study if they have a metallic object embedded or implanted in their body that is incompatible with Magnetic Resonance (MR) scanning, including MR incompatible pacemaker or defibrillator.