**7.3 Cardiogenic shock**

For those with unprotected left main disease (UPLM), both the ACC and ESC guidelines still give a **Class I** *recommendation for CABG in all cases* **(Classified as Grade A evidence for ESC and Grade B evidence for ACC)**[14, 26]. They have both also given a **IIa recommendation for PCI in Stable Ischemic Heart Disease (SIHD) in UPLM when the SYNTAX is 22 or less (eg isolated ostial or main trunk LM)** and **IIb recommendation for PCI for low or inter‐**

It is recognized however, that some populations are not expected to derive prognostic benefit from revascularization. In such groups for the purposes of alleviating symptoms refractory to optimal medical therapy, CABG and PCI have equivalent **Class I recommendation (level A evidence)** unless **SYNTAX is >22 in which case CABG is still favored (Class IIa recommen‐**

**7. PCI versus CABG in acute coronary syndromes versus stable ischemic**

Although there are limited studies designed to address this specific question, it is generally accepted that the same considerations that are used to decide between PCI and CABG in stable ischemic coronary artery disease would be applied when faced with an NSTEACS **(Class I recommendation, Level B evidence)**[14]. Comparisons between PCI and CABG have typically included a mixture of patients with stable and unstable symptoms [45]. The ERACI II study contained the highest proportion of patients with unstable symptoms constituting 92% of the randomized patients whereas MASS II included the least with 0% having unstable symptoms [60, 61]. However in a large meta-analysis including individual patient data from 10 large randomized studies (n=7812) did not reveal any significant interaction between the presence or absence of unstable symptoms and mode of revascularization (PCI vs CABG) with respect

The optimal approach to PCI in the setting of a NSTEACS and MVD is still somewhat uncertain. There are currently no randomized trials in the literature comparing the multivessel PCI to

Primary PCI remains the main modality of revascularization in STEACS *(Class I recommenda‐ tion, Level A evidence)*. It is common to encounter MVD during the index angiogram for STEACS having an estimated incidence of up to 40-50 percent [62]. Current evidence supports primary PCI of the culprit vessel only, in the absence of hemodynamic instability, as the optimal approach [14, 62, 63]. *Multivessel PCI in this setting has been associated with a higher mortality and is not recommended (Class III recommendation, Level B evidence) [14, 62, 63].* The approach to residual coronary disease has been a subject of controversy and the decisions are likely made

**mediate SYNTAX score (<33) (Level B evidence)** [14, 26]

**7.1. Non-ST-elevation acute coronary syndromes (NSTEACS)**

to mortality outcomes over a 5 year period [45].

**7.2. ST -elevation acute coronary syndromes (STEACS)**

culprit only PCI in NSTEACS [62].

clinically on an individual basis.

**dation, level B evidence)** [14].

334 Artery Bypass

**coronary artery disease**

The optimal mode of revascularization in patients with multivessel disease and cardiogenic shock is still under debate due to lack of supporting evidence for or against either PCI or CABG. It has been previously shown in the **Should We Emergently Revascularize Occluded Arteries for Cardiogenic Shock (SHOCK) Trial** that urgent revascularization with PCI or CABG for cardiogenic shock in the setting of STEACS has *mortality benefit* with an **ARR of 13 percent** or **NNT of 8** at 6 months compared with medical management [64]. This difference continued out to one year and remained stable at long-term follow up [Figure 6] [65, 66]. In the revascu‐ larization group, 64 percent were treated with angioplasty whereas 36 percent were treated with CABG [64]. Interestingly, because the mode of revascularization was at the discretion of the treating physicians, patients treated with CABG compared with those that received PCI tended to more often have LM disease and 3VD [64]. Nevertheless, there was no significant difference between patients treated with PCI versus CABG at either 30 days or at 1 year [64]. Certainly the advantage of PCI for revascularization over CABG would be a reduced time required to achieve revascularization; the time of randomization to first revascularization attempt was 0.9 hour for PCI and 2.7 hours for CABG [64].

**Figure 6.** Kaplan-Meier Survival Curves For Early Revascularization Versus Initial Medical Stabilization in Long Term Follow-Up. ERV= Early Revascularization; IMS =Initial Medical Stabilization. Reproduced with permission from Hoch‐ man JS. et al. JAMA 2006. 295;21: 2511-2515.

There is a lack of randomized data regarding the optimal mode of revascularization in cardiogenic shock for acute coronary syndromes [67]. Currently, both the ACC and ESC guidelines recommend that PCI (or emergency CABG) should be performed on patients who candidates for revascularization in the setting of STEMI and severe heart failure or cardiogenic shock *(Class I recommendation, Level B evidence)* [14, 26]. Although the data upon which this recommendation is based does not show a preferential benefit to either mode of revasculari‐ zation, both guidelines favor PCI as the primary mode of revascularization in cardiogenic shock [14, 26]. The ACC guidelines do recognize however, that "select patients with severe 3VD or LM disease can benefit from emergency CABG" [14].
