Hypothesis The primary hypothesis is that metoprolol succinate will reduce the risk of COPD exacerbations as compared to placebo. The secondary hypothesis is that metoprolol succinate will not adversely impact lung function, exercise tolerance, dyspnea or quality of life as compared to placebo.~Study Flow Patients will be screened and then randomized over a 2 week period and will then undergo a dose titration period for the following six weeks. Thereafter patients will be followed for 42 additional weeks on their target dose of metoprolol or placebo followed by a 4 week washout period.~Specific Aims:~Primary: To determine the effect of once daily metoprolol succinate compared with placebo on the time to first exacerbation in moderate to severe COPD patients who are prone to exacerbations and who do not have absolute indications for beta-blocker therapy.~Secondary: To estimate the effect of metoprolol succinate compared with placebo on:~The rate and severity of COPD exacerbations over 12 months~Incidence and severity of metoprolol-related side effects including those that require cessation of drug~Lung function as assessed by spirometry, dyspnea as assessed by the Modified Medical Research Council Scale (MMRC) and San Diego Shortness of Breath Questionnaire, exercise tolerance as measured by six minute walk test (6MWD), and quality of life as assessed by the Short Form 36, St. Georges Respiratory Questionnaire (SGRQ) and COPD Assessment Test (CAT) and Personal HEART Score.~Hospitalizations~The rate of major adverse cardiovascular events (MACE) (defined by cardiovascular death, hospitalization for myocardial infarction, heart failure, or stroke), percutaneous coronary intervention or coronary artery bypass grafting~All-cause mortality~Secondary subgroup analyses for 1) cardiovascular risk based on Personal HEART Score and 2) age greater versus less than 65.
This is a multicenter, prospective, randomized, double-blind, placebo-controlled trial that will enroll 1028 patients with at least moderately severe COPD over a three year period and follow them at regular intervals for one year. The primary endpoint is time to first acute exacerbation. Secondary endpoints include rates and severity of COPD exacerbations, cardiovascular events, all-cause mortality, lung function, dyspnea, quality of life and metoprolol-related side effects.