<unk> <unk><unk><unk>  stenosis is associated with poor patient outcomes secondary to ischemia of the large area of the myocardium which it supplies. Traditionally, CABG was indicated for<unk> <unk><unk> . The SYNTAX trial demonstrated non-inferiority of PCI to CABG in a subgroup of patients with low to intermediate SYNTAX score. This clinical trial suggests a possible indication for a PCI option for the treatment of<unk> <unk><unk> . Subsequently, the PRECOMBAT trial was conducted to compare the two<unk> s. In 2016, two large trials results were published (EXCEL trial and NOBLE trial) addressing the comparison of CABG and PCI in patients with<unk> <unk><unk>  in this particular subgroup of interest with low to intermediate SYNTAX scores.
The 5-year NOBLE trial results reported event rates of 29% in the primary endpoint (Major Adverse Cardiovascular or Cerebrovascular Events) in the PCI group compared to 19% in the CABG group (HR: 1.45; p=0.0066); 12% vs. 9% in all-cause mortality (HR: 1.07, p=0.77); and 5% vs. 2% in stroke (HR:2.25, p=0.073). 
The 3-year EXCEL trial results reported non-inferiority of PCI with a 15.4% vs. 14.7% occurrence of the primary endpoint of MACCE (HR:1.00, p=0.02) between PCI and CABG, respectively. In terms of superiority, 3 year results demonstrate a PCI vs. CABG event rate of  2.3% vs. 2.9% in stroke (HR:0.77, p=0.37), and 8.2% vs. 5.9% in all-cause mortality (HR:1.34, p=0.11). At 30 days, the EXCEL trial demonstrate a statistically significant reduction in MACCE (HR:0.61, p<0.001) with PCI; however, a non-significant reduction in stroke(HR:0.50, p=0.15) and all-cause mortality (HR:0.90, p=0.82).
The variability in the results of the latest two trials (NOBLE and EXCEL) is a topic of much discussion. The complexity of<unk> <unk><unk> , type of stent, complexity of<unk>  in other vessels, and duration of follow up may affect results. Additionally, the effect of the anti-platelet treatments administered post-operatively, as well as the variability in the specific CABG procedures performed by the surgeon may contribute to the variability in the results.
Intervention in left main coronary artery disease
PCI in the angulated or tortuous lesion
PCI in the patient with severely depressed ventricular function
Antiplatelet therapy to support PCI
PCI in the patient with refractory ventricular arrhythmia
Chronic stable angina revascularization drug eluting stents
PCI in the long lesion
Chronic stable angina transmyocardial revascularization