What Procedure to Choose?
Although many indications are the same for performing either PCI or CABG, these two procedures have inherently different mechanisms.  While PCI mitigates an obstruction, it can not prevent plaque progression or rupture in other involved segments of the artery. On the contrary, CABG is able to prevent future ischemic insults caused by plaque progression or rupture in other involved segments of the artery. Most studies report the same outcome with PCI and CABG, but there are some reports that favor CABG over PCI: The SYNTAX trial with 705 patients demonstrated a significantly higher rate of major adverse cardiovascular events and mortality rate among those who received PCI than the CABG cohort.  Two Studies reported that CABG is more effective in prevention of late spontaneous MI when compared to PCI.   ACA 2021 revascularization guideline recommends to consider the following factors to decide whether to chose PCI or CABG:  SYNTAX Score  SYNTAX score derived from a clinical trial with the same name which predicts the grade of the anatomic complexity and can be used as a decision-making tool. This score is a guide for selection of a revascularization procedure in patients with multivessel coronary artery disease. All cause mortality rate among patients with a coronary artery disease -associated SYNTAX score equal or greater than 33 were significantly lower when undergone CABG than PCI For patients with SYNTAX score lower than 33, no differences have been report in mortality rate of CABG and PCI Compliance to medications Preferences of patient Individual factors, such as anatomic complexity, which is discussed in the following table: 


PCI would help patients with STEMI and ischemic symptoms for less than 12 hours.  Rescue PCI is recommended for STEMI patients who failed re-perfusion after fibrinolytic therapy to improve the survival.    PCI has been related to improved survival rate when done in STEMI patients who are stable and presented 12 to 24 hours after symptom onset.  Regardless of time from MI, PCI can increase survival in STEMI patients who developed complications such as ongoing ischemia, acute sever heart failure, or life-threatening cardiac arrhythmia.  Performing the PCI is not beneficial in stable and asymptomatic STEMI patients who have a totally occluded infarct artery >24 hours after symptom onset with no evidence for sever ischemia.  The role of PCI in asymptomatic STEMI patients who are presenting after 12 to 24 hours after symptom onset is not well studied.  However, based on a small trial named BRAVE-2 a reduction in left ventricular infarct size has been reported among asymptomatic STEMI patients who were treated with an invasive strategy of coronary stent within 12 to 48 hours after symptom onset, compared to conservative therapies.  Both PCI and CABG are indicated in patients with STEMI, cardiogenic shock, and hemodynamic instability.  CABG is recommended for patients with STEMI who have mechanical complications such as ventricular septal rupture, mitral regurgitation because of papillary muscle infarction or rupture, or free wall rupture.  Emergent or urgent CABG is recommended in STEMI patients whose PCI is not feasible with a large area of myocardial involvement. On the other hand, emergent or urgent CABG should be avoided in these patients in the absence of ischemia or large myocardial involvement. Furthermore, CABG is usually avoided if patients' distal targets are poor.   The following algorithm demonstrates the proper revascularization in STEMI patients. 


The sole condition that fibrinolytic therapies are superior to PCI is when the duration from hospital presentation to PCI is anticipated to be more than 120 minutes. An early revascularization strategy could increase the survival rate in patients with STEMI complicated by cardiogenic shock.
Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are commonly used to assess the lesion significant. Fractional flow reserve (FFR) compares the maximal blood flow distal to the lesion to the normal maximal blood flow. On the other hand iFR compares the instantaneous wave-free ratio of the coronary pressure distal to the lesion during the diastole with the aortic pressure.  Reported in numbers of trials which used FFR, FFR -guided PCI was successful in lowering the revascularization rate, procedure-related chest pain in patients with stable coronary artery disease and functionally significant stenosis.    In one of these trials patients with abnormal FFR significantly benefited from PCI over medical therapy with lower rate of ischemia -driven revascularization and shorter procedural time.  FFR -guided revascularization with CABG was more off-pump with fewer anastomosis and simpler procedure compared to CABG with angiogram -guided revascularization in one of the clinical trials.    Although other studies reported similar outcomes in both.   iFR measure does not require the administration of adenosine has been also studied in clinical trials. Results supported that this measure is not inferior to FFR and also showed less adverse outcome related to the procedure.  Lower rate of long-term major adverse cardiac events has been reported when PCI was deferred with FFR greater than 0.80 or iFR that is >0.89. One of the trials named DEFER (Deferral of Percutaneous Intervention) reported that the rate of adverse outcome cardiac outcomes is similar in both group of patients whose PCI has been deferred either with a FFR greater than 0.75 or intermediate angiographic measures. </s>