Observational analyses have reported an association be- tween elevated perioperative heart rates and adverse out- comes,228,229 but it is difficult to recommend a specific heart rate for all CABG patients. Instead, the heart rate may need to be adjusted up or down to maintain an adequate cardiac output.230,231 Similarly, controversy exists about management of blood pressure in the perioperative period,232 particularly with regard to systolic pressure233 and pulse pressure.234 Intraoperative hypotension is considered to be a risk factor for adverse outcomes in patients undergoing many types of surgery. Unique to CABG are unavoidable periods of hypo- tension associated with surgical manipulation, cannulation for CPB, weaning from CPB, or during suspension and stabili- zation of the heart with off-pump CABG. Minimization of such periods is desirable but is often difficult to achieve, particularly in patients who are unstable hemodynamically. 2.2. Clinical Subsets 2.2.1. CABG in Patients With Acute MI: Recommendations Class I 1. Emergency CABG is recommended in patients with acute MI in whom 1) primary PCI has failed or cannot be performed, 2) coronary anatomy is suit- able for CABG, and 3) persistent ischemia of a significant area of myocardium at rest and/or hemo- dynamic instability refractory to nonsurgical ther- apy is present.235 239 (Level of Evidence: B) 2. Emergency CABG is recommended in patients un- dergoing surgical repair of a postinfarction mechan- ical complication of MI, such as ventricular septal rupture, mitral valve insufficiency because of papil- lary muscle infarction and/or rupture, or free wall rupture.240 244 (Level of Evidence: B) 3. Emergency CABG is recommended in patients with cardiogenic shock and who are suitable for CABG irrespective of the time interval from MI to onset of shock and time from MI to CABG.238,245 247 (Level of Evidence: B) 4. 