Supplemental (Online-Only) Material

Appendix E1. Variables Considered in Multivariable Analyses

Demographics

Age (y), sex, race (white, black, other), weight (kg), height (cm), weight/height ratio, body surface area (m2), body mass index (kg•m-2)

Status/symptoms

New York Heart Association functional class (I-IV), emergency operation

Cardiac comorbidity

Prior myocardial infarction, atrial fibrillation or flutter, heart failure

Noncardiac comorbidity

Treated diabetes, peripheral arterial disease, carotid disease, hypertension, history of smoking, prior stroke, cholesterol (mg•dL-1), triglycerides (mg•dL-1), creatinine (mg•dL-1)

Coronary anatomy

Number of coronary systems diseased (≥50% stenosis), left anterior descending (LAD) disease (≥50%, moderate [50% to 69%], severe [≥70%]), left circumflex (LCx) system disease (≥50%, moderate [50% to 69%], severe [≥70%]), right coronary artery (RCA) system disease (≥50%, moderate [50% to 69%], severe [≥70%]), diagonal (Dg) disease (≥50%, moderate [50% to 69%], severe [≥70%]), location of moderate CAD (LAD, Dg, LCx, RCA)

Coronary artery bypass grafting procedures

Number of internal thoracic artery (ITA) grafts used to graft severely stenosed arteries (none, 1, 2), conduit used to bypass moderate CAD (none, ITA, saphenous vein [SV] graft, radial artery, other), graft locations (LAD, LAD diagonals, LCx territory, RCA territory), interaction terms for conduit used to bypass moderate CAD in each location (none, ITA, SV)

Support

Cardiopulmonary bypass (off-pump versus on-pump), bypass time (min)

Experience

Date of operation (years since January 1, 1972)

Table E1. Postoperative Angiograms Available for Analysis

/ Time from Index CABG /
>0 / ≥3 mo / ≥6 mo / ≥1 y / ≥5 y / ≥10 y / ≥15 y / ≥20 y /
Nongrafted native vessel
# Patients / 489 / 477 / 469 / 422 / 260 / 134 / 66 / 21
# Angios / 683 / 665 / 648 / 578 / 338 / 164 / 72 / 22
ITA-grafted native vessel
# Patients / 371 / 357 / 351 / 337 / 237 / 112 / 34 / 6
# Angios / 541 / 520 / 509 / 481 / 322 / 141 / 38 / 6
SV-grafted native vessel
# Patients / 957 / 921 / 899 / 842 / 607 / 307 / 100 / 14
# Angios / 1,371 / 1,325 / 1,295 / 1,216 / 836 / 402 / 124 / 18
Grafts
# Patients (ITA) / 376 / 362 / 357 / 345 / 245 / 118 / 33 / 5
# Angios / 560 / 538 / 527 / 499 / 334 / 149 / 39 / 5
# Patients (SV) / 1,016 / 981 / 959 / 902 / 653 / 325 / 101 / 13
# Angios / 1,467 / 1,420 / 1,390 / 1,310 / 907 / 429 / 127 / 17

Angios = angiograms; CABG = coronary artery bypass grafting; ITA = internal thoracic artery; SV = saphenous vein.

Table E2. Risk Factors Associated With Higher Likelihood of Having Higher Grade of Postoperative Stenosis (More Progression of Disease) in Left-sided Coronary Arteries versus Right Coronary Artery

Factor / Estimate ± SE / p
Overall
Younger age / -1.00 ± 0.33 / .003
Diabetes / 0.42 ± 0.195 / .03
Peripheral arterial disease / 0.53 ± 0.23 / .02
No prior stroke / -0.79 ± 0.40 / .05
Male / 0.23 ± 0.16 / .17
Comparisons
No graft (left side) / reference / —
ITA graft (left side) / 1.6 ± 0.20 / <.0001
SV graft (left side) / 2.0 ± 0.19 / <.0001
No graft (RCA) / 0.97 ± 0.22 / <.0001
ITA graft (RCA) / 1.7 ± 0.46 / .0001
SV graft (RCA) / 2.7 ± 0.21 / <.0001

Disease progression was similar in ITA-graftedmoderately stenosed left-sided vessels and ITA-grafted moderately stenosed RCAs(0.14 ± 0.45, p = .8).

Disease progression was higher in SV-grafted moderately stenosed RCAs than in SV-grafted moderately stenosed left-sided coronary arteries(0.75 ± 0.16, p .0001).

ITA = internal thoracic artery; LAD = left anterior descending coronary artery; SE = standard error; SV = saphenous vein.

Fig E1. Frequency of occurrence of graft stenosis (percentage of lumen diameter).

ITAs = internal thoracic artery grafts; SVs = saphenous vein grafts.