Most patients with persistently reduced EF after CABG are likely to have had a prior MI, and in this patient popula- tion, evidence supports the use of -blockers on top of back- ground therapy with ACE inhibitors, even in the absence of heart failure. Three specific -blockers (carvedilol, bisoprolol, and sustained-release metoprolol succinate) have documented benefits for morbidity and mortality and are highly recom- mended for patients with active or past symptoms of heart In addition, these medications reduce heart fail- ure symptoms, enhance patients overall sense of well-being, and reduce hospitalization, even among patients already tak- ing ACE inhibitors.197,208,238,239 Contraindications to -blocker use include bradycardia, hypotension, severe bronchospastic airway disease, low-output state, or severe, actively decom- pensated heart failure. ACE Inhibitor and ARB Therapy ACE inhibitors exert their effects by suppressing the effects of angiotensin II, a potent vasoconstrictor that reduces renal perfusion, stimulates LV hypertrophy and cardiac remodel- ing, and enhances the release of arginine, vasopressin, proin- flammatory cytokines, and aldosterone.237 Inhibition of ACE results in decreased levels of angiotensin II and inhibits the breakdown of bradykinin, a peptide with favorable properties, including antihypertensive, antiremodeling, and natriuretic effects. 