The present invention relates to compounds of Formula (Ia) and pharmaceutical compositions thereof that modulate the activity of the beta-3 adrenergic receptor. Compounds of the present invention and pharmaceutical compositions thereof are directed to methods useful in the treatment of a beta-3 adrenergic receptor-mediated disorder, such as, heart failure； cardiac performance in heart failure； mortality, reinfarction, and/or hospitalization in connection with heart failure； acute heart failure； acute decompensated heart failure； congestive heart failure； severe congestive heart failure； organ damage associated with heart failure (e.g., kidney damage or failure, heart valve problems, heart rhythm problems, and/or liver damage)； heart failure due to left ventricular dysfunction； heart failure with normal ejection fraction； cardiovascular mortality following myocardial infarction； cardiovascular mortality in patients with left ventricular failure or left ventricular dysfunction； left ventricular failure； left ventricular dysfunction； class II heart failure using the New York Heart Association (NYHA) classification system； class III heart failure using the New York Heart Association (NYHA) classification system； class IV heart failure using the New York Heart Association (NYHA) classification system； LVEF<；40% by radionuclide ventriculography； LVEF≤35% by echocardiography or ventricular contrast angiography； and conditions related thereto.
