journal image CABG vs PCI

PCI vs CABG in Patients with Unprotected Left Main Coronary Artery Disease

Key Takeaways

  • This meta-analysis evaluated 6 randomized controlled trials to determine outcome differences between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) among patients with unprotected left main coronary artery disease ([ULMCAD] n = 4686).
  • Compared with CABG, PCI correlated with significantly lower rates of 30-day stroke (P = 0.007), death or MI (P = 0.04), or all-cause death, MI, or stroke (P = 0.01).
  • In the PCI group, there was a significantly lower rate of 30-day stroke incidence (P = 0.007) and all-cause death, MI, or stroke (P = 0.01).
  • The authors found no significant difference in outcomes at long-term follow-up (median 39 months) between the two groups.

Reference: Palmerini T et al. Am Heart J. 2017;190:54-63.

Unprotected left main coronary artery disease (ULMCAD) is mostly managed by coronary artery bypass grafting (CABG). There are some reports showing that percutaneous coronary intervention (PCI) may prove to be an effective alternative strategy for select patients.1,2 Previous research has concluded, however, that PCI provides no real benefit over CABG for patients with ULMCAD.2

The NOBLE and EXCEL trials provide more results as to the best revascularization strategy in the setting of ULMCAD. In the EXCEL trial, 1905 ULMCAD patients were randomized to either everolimus-eluting stents or CABG.3 This trial reported similar rates of all-cause death, myocardial infarction (MI), or stroke between PCI and CABG at follow-up. The NOBLE trial, however, reported higher composite rates of stroke, MI, or unplanned revascularization in PCI at median follow-up.4

In a meta-analysis from the American Heart Journal, Palmerini et al evaluated 6 randomized controlled trials to determine mortality differences between PCI and CABG among patients with ULMCAD (n = 4686).5 Compared with CABG, PCI correlated with significantly lower rates of 30-day stroke (P = 0.007), death or MI (P = 0.04), or all-cause death, MI, or stroke (P = 0.01).

Among patients in the PCI (n = 2347) and CABG (n = 2239) group, the following 30-day outcomes were observed:

Table 1. 30-day outcomes

MortalityMyocardial infarctionStroke
PCI (n)15506
CABG (n)246922
P value.16.08.007

Additionally, major adverse cardiac and cerebrovascular events (defined as all-cause death, MI, or stroke) at 30 days were significantly different between PCI and CABG (OR [95% CI] 0.62 [0.45-0.86]; P =.004).

A median follow-up of 39 months assessed all-cause mortality, cardiac mortality, MI, or stroke. The authors found no significant difference in outcomes between the two groups during this follow-up period. There was, however, significantly more unplanned revascularization in the PCI group vs the CABG group at long-term follow-up (HR 1.74, 95% CI 1.47-2.07, P < .0001). Researchers found a significant interaction between treatment effect and the time for the composite risk for MI, death, or stroke (Pinteraction <.0001), demonstrating higher event rates after 30 days in the PCI group.

The SYNTAX score predicted lower relative risk of long-term mortality with PCI compared with CABG in patients with low SYNTAX score and higher relative risk among patients with a high SYNTAX score. These findings are consistent with those from Zhang et al that showed that, compared with CABG, the use of new-generation drug-eluting stents with PCI provided a safer revascularization strategy for patients with ULMCAD despite greater rates of repeat revascularization.6

Although there were lower events in the PCI group at 30 days in this study, both CABG and PCI are effective revascularization modalities which can be used to treat ULMCAD. In these trials, only patients who were surgically eligible were included. Additional study of ULMCA PCI in surgically ineligible patients with reduced LVEF are needed. It’s important to consider future trials which will examine hemodynamic support in this population group, if necessary, and how this support might affect long-term outcomes among patients receiving PCI.


  1. Levine GN, Bates ER, Blankenship JC, et al. 2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions. J Am Coll Cardiol. 2011;58:e44-122.
  2. Papadopoulos K, Lekakis I, Nicolaides E. Outcomes of coronary artery bypass grafting versus percutaneous coronary intervention with second-generation drug-eluting stents for patients with multivessel and unprotected left main coronary artery disease. SAGE Open Med. 2017;5:2050312116687707.
  3. Stone GW, Sabik JF, Serruys PW, et al. Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease. N Engl J Med. 2016;375(23):2223-2235.
  4. Mäkikallio T, Holm NR, Lindsay M, et al. Percutaneous coronary angioplasty versus coronary artery bypass grafting in treatment of unprotected left main stenosis (NOBLE): a prospective, randomised, open-label, non-inferiority trial. Lancet. 2016;388(10061):2743-2752.
  5. Palmerini T, Serruys P, Kappetein AP, et al. Clinical outcomes with percutaneous coronary revascularization vs coronary artery bypass grafting surgery in patients with unprotected left main coronary artery disease: A meta-analysis of 6 randomized trials and 4,686 patients. Am Heart J. 2017;190:54-63.
  6. Zhang XL, Zhu QQ, Yang JJ, et al. Percutaneous intervention versus coronary artery bypass graft surgery in left main coronary artery stenosis: a systematic review and meta-analysis. BMC Med. 2017;15(1):84.


To learn more about the Impella® platform of heart pumps, including important risk and safety information associated with the use of the devices, please visit: