Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting - POPular CABG

Contribution To Literature:

The POPular CABG trial showed that ticagrelor + low-dose aspirin is not superior to low-dose aspirin for SVG patency at 1 year following on-pump CABG.

Description:

The goal of the trial was to assess the safety and efficacy of ticagrelor among patients undergoing coronary artery bypass grafting (CABG).

Study Design

Patients scheduled for CABG were randomized in a 1:1 fashion to either ticagrelor 90 mg BID (n = 247) or placebo (n = 249). Antiplatelet therapy was resumed as soon as possible after post-CABG. All patients received 80-100 mg of aspirin, continued indefinitely.

  • Total number of enrollees: 496
  • Duration of follow-up: 1 year
  • Mean patient age: 68 years
  • Percentage female: 33%
  • Percentage with diabetes: 26%

Inclusion criteria:

  • Age >21 years
  • Indication for CABG with ≥1 saphenous vein graft (SVG)

Exclusion criteria:

  • Indication for dual antiplatelet therapy (DAPT) or vitamin K antagonist

Other salient features/characteristics:

  • Acute coronary syndrome (ACS): 31%
  • Left ventricular ejection fraction >50%: 78%
  • Cardiopulmonary bypass use: 95%
  • Mean number of vein grafts/patient: 2.2

Principal Findings:

The primary outcome, SVG occlusion at 1 year on computed tomography/coronary angiography for ticagrelor vs. placebo, was 10.5% vs. 9.1% (odds ratio 1.29, 95% confidence interval 0.73-2.30, p = 0.38).

  • Per-patient basis: 14.1% vs. 12.1% (p = 0.54)

Secondary outcomes for ticagrelor vs. placebo:

  • 30-day Bleeding Academic Research Consortium (BARC) 3-5 bleeding: 2.4% vs. 1.6% (p = 0.51)
  • 1-year BARC 3-5 bleeding: 3.6% vs. 2.4% (p = 0.42)
  • Cardiovascular death: 0.4% vs. 0.8%
  • ACS/myocardial infarction: 2.4% vs. 1.2%
  • Revascularization: 5.3% vs. 0.8% (p < 0.05)

Interpretation:

The results of this trial indicate that that ticagrelor + low-dose aspirin is not superior to low-dose aspirin for SVG patency at 1 year following CABG. Bleeding was higher with ticagrelor, but not statistically significant. Almost all patients underwent on-pump surgery. This trial was not powered for clinical endpoints.

This is an interesting and important trial. The DACAB trial suggested higher vein graft patency with DAPT using low-dose aspirin + ticagrelor compared with low-dose aspirin alone. SVG patency in the aspirin arm of that trial was much lower than noted in this trial (~77% in DACAB, ~91% in current trial). This is more in line with other contemporary CABG trials, which have reported 1-year SVG patency rates between 85-95%. One big difference is that approximately three-fourths of CABG surgeries were performed off-pump in DACAB, while nearly all patients were done on-pump in the current trial. It is possible that DAPT may have a role in off-pump coronary artery bypass patients, but not in on-pump CABG patients.

References:

Willemsen LM, Janssen PW, Peper J, et al. The Effect of Adding Ticagrelor to Standard Aspirin on Saphenous Vein Graft Patency in Patients Undergoing Coronary Artery Bypass Grafting (POPular CABG): A Randomized, Double-Blind, Placebo-Controlled Trial. Circulation 2020;142:1799-807.

Editorial: Goldman S. Antiplatelet Agents Added to Aspirin: No Benefit for SVG Patency After CABG. Circulation 2020;142:1808-9.

Presented by Dr. Laura Marijke Willemsen at the European Society of Cardiology Virtual Congress, August 31, 2020.

Clinical Topics: Acute Coronary Syndromes, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and ACS, Interventions and Imaging, Angiography, Computed Tomography, Nuclear Imaging

Keywords: ESC Congress, ESC20, Acute Coronary Syndrome, Aspirin, Cardiac Surgical Procedures, Cardiopulmonary Bypass, Coronary Angiography, Coronary Artery Bypass, Coronary Artery Bypass, Off-Pump, Myocardial Revascularization, Platelet Aggregation Inhibitors, Saphenous Vein, Tomography, X-Ray Computed


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