Relation between functional coronary artery stenosis and graft occlusion after coronary artery bypass grafting

J Thorac Cardiovasc Surg. 2021 Mar;161(3):1010-1018.e1. doi: 10.1016/j.jtcvs.2020.11.072. Epub 2020 Dec 1.

Abstract

Objectives: This study was conducted to evaluate graft patency rates during the 5 years after coronary artery bypass grafting according to the functional significance of the coronary artery stenosis, as determined by myocardial single-photon-emission computed tomography.

Methods: Two hundred ninety-five patients who underwent coronary artery bypass grafting using Y-composite grafts based on the in situ left internal thoracic artery, and in whom preoperative stress/rest myocardial single-photon-emission computed tomography and 1-year angiographies were available were enrolled. Seven hundred sixty-nine and 262 distal anastomoses were constructed to ischemic and nonischemic areas, respectively. One-year and 5-year angiographic occlusion rates were evaluated in all and 80.3% of study patients, respectively. Factors associated with graft occlusion were evaluated using generalized linear mixed-effects models.

Results: Overall 1- and 5-year graft occlusion rates were 4.3% (44 of 1031 distal anastomoses) and 5.5% (45 out of 820), respectively. The occlusion rates of grafts bypassed to vessels with functionally significant and insignificant stenosis were 2.7% (21 out of 769) and 8.8% (23 out of 262) at 1 year and were 4.0% (25 out of 618) and 9.9% (20 out of 202) at 5 years, respectively. Graft occlusion during the 5 years after coronary artery bypass grafting was associated with the functional significance of coronary artery stenosis (odds ratio, 0.50; 95% confidence interval, 0.28-0.92). The odds ratio of the graft occlusion according to functional ischemia was lower and significant in grafts to arteries with intermediate stenosis (stenosis ≥70% but <90%; odds ratio, 0.34; 95% confidence interval, 0.13-0.93) whereas it was higher and insignificant in grafts to arteries with severe stenosis (≥90% stenosis; odds ratio, 0.76; 95% confidence interval, 0.33-1.72).

Conclusions: Graft occlusion during the 5 years after coronary artery bypass grafting was associated with the functional significance of coronary artery stenosis, particularly when the stenosis degree was not severe.

Keywords: coronary artery bypass grafting; myocardial ischemia; outcomes.

Publication types

  • Observational Study
  • Webcast

MeSH terms

  • Aged
  • Coronary Angiography
  • Coronary Artery Bypass / adverse effects*
  • Coronary Circulation
  • Coronary Stenosis / diagnostic imaging
  • Coronary Stenosis / physiopathology
  • Coronary Stenosis / surgery*
  • Female
  • Graft Occlusion, Vascular / diagnostic imaging
  • Graft Occlusion, Vascular / etiology*
  • Graft Occlusion, Vascular / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Myocardial Perfusion Imaging
  • Predictive Value of Tests
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Severity of Illness Index
  • Time Factors
  • Tomography, Emission-Computed, Single-Photon
  • Treatment Outcome
  • Vascular Patency