Supplemental (Online-Only) Material

Appendix E1. Variables Considered in Multivariable Analyses

DemographicsAge (y), sex, race (white, black, other), weight (kg), height (cm), weight/height ratio,

body surface area (m2), body mass index (kg•m-2)

Status/symptomsNew York Heart Association functional class (I-IV), emergency operation

Cardiac comorbidityPrior myocardial infarction, atrial fibrillation or flutter, heart failure

Noncardiac comorbidityTreated 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 anatomyNumber 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)

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

ExperienceDate 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-grafted moderately 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.