Cardiovascular Critical Care I

use of cardiopulmonary bypass (or performing off pump), are too broad to be discussed in greater

detail in this chapter. According to the Society of Thoracic Surgeons/American College of Cardiology/

American Heart Association (STS/ACC/AHA) CABG guidelines, emergency CABG is recommended

in patients with an acute MI in the following scenarios (J Am Coll Cardiol 2011;58:e123-210):

Primary PCI has failed or cannot be performed

Coronary anatomy is more suitable for CABG

Persistent ischemia of a significant area of myocardium at rest and/or hemodynamic instability

refractory to nonsurgical therapy is present

septal rupture, mitral valve insufficiency caused by papillary muscle infarction and/or rupture, or

free wall rupture)

Patients with cardiogenic shock who are suitable for CABG, irrespective of the time interval from

MI to onset of shock and time from MI to CABG

Patients with life-threatening ischemic ventricular arrhythmias in the presence of a left main

stenosis of 50% or more and/or three-vessel CAD

CABG use is reasonable as a revascularization strategy in patients with multivessel CAD with

recurrent angina or MI within the first 48 hours of STEMI presentation as an alternative to a more

delayed strategy.

Early revascularization with PCI or CABG is reasonable for select patients older than 75 years with

ST-segment elevation or left bundle branch block who are suitable for revascularization irrespective

of the time interval from MI to onset of shock.

Medical management – No revascularization:

Less invasive strategies may be opted for rather than revascularization in some patients.

Considerations reinforce a patient-centered approach driven by evidence of ongoing/recurrent

ischemia and feasibility of revascularization, including myocardial viability, patient frailty, and

comorbid disease states.

Ongoing care outlined in section E remains the focus of optimizing aggressive medical management.

The roles and combinations of antithrombotics continue to be refined in select populations (those with

NSTEMI/ACS, STEMI, and PCI). For the most current guidelines and landmark trials, please see www.

acc.org/guidelines.

Platelets can be activated by several different mechanisms, only some of which can be inhibited

by medications.

Clopidogrel had previously been the standard of care P2Y12 inhibitor but has fallen out of

favor in ACS because of its slow onset of action, variable platelet inhibition because of genetic

polymorphisms (CYP2C19), drug interactions, and delayed onset of action, leading to an increased

risk of inadequate antiplatelet response or bleeding complications. Clopidogrel may still be used in

patients who are medically managed for ACS, in those receiving stents for non-ACS indications,

among patients at high risk of bleeding, those maintained on concomitant anticoagulation and

when cost of other P2Y12 inhibitors is prohibitive.