Percutaneous Coronary Intervention Proven Non-Inferior to Coronary-Artery Bypass Grafting in Left Main Coronary Artery Disease

Ling Jun Chen, Mercer University College of Pharmacy

Coronary artery disease leads to the narrowing of coronary arteries and is associated with risk factors that include cigarette smoking, hypertension, hyperlipidemia, and diabetes. [1]  European and U.S. guidelines have declared that patients with coronary artery disease have an increased risk of developing ischemia and infarction.  Coronary-artery bypass grafting (CABG) is recommended for left main coronary artery disease and the procedure requires an open-heart surgery that can increase the chances of an infection and other post-surgical adverse event. [2]

Percutaneous coronary intervention (PCI) is indicated for treating partially and completely occluded coronary vessels.  During the procedure, small metal cylinders (stents) are placed inside diseased blood vessels to assist their expansion. [1]  Drug-eluting stents have a coating that releases medications, such as everolimus, and have been proven to maintain the open blood vessels and prevent clot formation on the stent. [3]

Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease (EXCEL) [4]

Design International, open-label, multicenter, randomized trial; N= 1,905
Objective To determine whether percutaneous coronary intervention (PCI) is non-inferior to coronary-artery bypass grafting (CABG)
Study Groups PCI (n= 948); CABG (n= 967)
Methods The PCI group used fluoropolymer-based cobalt–chromium everolimus-eluting stents.  Dual antiplatelet therapy was initiated before PCI and was continued for a minimum of 1 year thereafter.   In the CABG group, aspirin was administered during the perioperative period and the use of clopidogrel during follow-up was allowed.  The Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Sugery (SYNTAX) scores were measured to assess the coronary vasculature.  Higher scores indicated a more complex coronary structure.  Intravascular ultrasonographic imaging guidance was used in the PCI group.
Duration 3 years
Primary Outcome Measure Rate of composite death from any cause, stroke, or myocardial infarction, ischemia-driven revascularization, all revascularization bleeding, and blood transfusion
Baseline Characteristics   PCI CABG
Mean age, years ± SD 66.0 ± 9.6 65.9 ± 9.5
Male, n (%) 722 (76.2) 742 (77.5)
White, n (%) 844 (91.5) 853 (92.0)
Hypertension, n (%) 703 (74.5) 701 (73.9)
Hyperlipidemia, n (%) 668 (71.5) 652 (69.3)
Current smoker, n (%) 222 (24.1) 193 (20.8)
Prior myocardial infarction, n (%) 169 (18.1) 169 (18.1)
Prior PCI, n (%) 174 (18.4) 152 (15.9)
Prior CABG, n (%) 0 (0) 0 (0)
Congestive heart failure, n (%) 67 (7.1) 59 (6.2)
Prior stroke or transient ischemic attack, n (%) 52 (5.5) 67 (7.0)
Peripheral vascular disease, n (%) 97 (10.3) 84 (8.8)
Chronic obstructive pulmonary disease, n (%) 65 (6.9) 81 (8.5)
Results   PCI, n (%) CABG, n (%) p-value
Death, stroke, or myocardial infraction (MI) at 30 days 46 (4.9) 75 (7.9) <0.001
Death, stroke, or MI at 3 years 137 (15.4) 135 (14.7) 0.02
Ischemia-driven revascularization 6 (0.6) 12 (1.4) 0.11
All revascularization 7 (0.7) 14 (1.5) 0.18
Bleeding 69 (7.3) 123 (13.0) <0.001
Blood transfusion 30 (3.2) 120 (12.7) <0.001
Adverse Events

 

Common Adverse Events: N/A
Serious Adverse Events: definite stent thrombosis (PCI: 5.4%; CABG: 0.7%)
Percentage that Discontinued due to Adverse Events: N/A
Study Author Conclusions In patients with left main coronary artery disease and low or intermediate SYNTAX scores by site assessment, PCI with everolimus-eluting stents was non-inferior to CABG with respect to the rate of the composite end point of death, stroke, or myocardial infarction at 30 days and 3 years.

 

 

An open-label design was required to use either PCI or CABG due to ethical and logistical reasons, which may have introduced bias.  Although low and intermediate SYNTAX scores were required during recruitment, 24% of patients consistently scored high during randomization.  This compromised the original methodology and may have altered the results.  Controlling the long-term maintenance medications and extending the follow-up are two strategies for future trials comparing CABG and PCI.

 

References

  1. Zhou C, Jeon Y, Meybohm P, Zarbock A, Li L, Hausenloy DJ. Renoprotection by remote ischemic conditioning during elective coronary revascularization: A systematic review and meta-analysis of randomized controlled trials. Int. J. Cardiol. 2016 Nov. 1.
  2. Windecker S, Kolh P, Alfonso F, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J 2014;35: 2541-619.
  3. Kurlansk P, et al. Coronary Artery Bypass Graft Versus Percutaneous Coronary Intervention: Meds Matters: Impact of Adherence to Medical Therapy on Comparative Outcomes. Ciruculation. 2016.
  4. 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.

 

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