Table 2.
Unassisted patency and secondary outcomes based on use of aspirin at baseline
| Unassisted Patency | On Aspirin at Baseline (n = 279) | Not On Aspirin at Baseline (n = 370) | Hazard Ratio (95% Confidence Interval)a,b |
|---|---|---|---|
| Overall loss of primary unassisted patency, % | 225 (81%) | 305 (82%) | 0.83 (0.68, 1.01) |
| Thrombosis, %b | 103 (37%) | 163 (44%) | 0.76 (0.58, 1.01) |
| Thrombosis with stenosis ≥50%, % | 64 (23%) | 84 (23%) | 0.90 (0.62, 1.31) |
| Thrombosis with stenosis <50%, % | 3 (1%) | 5 (1%) | 0.73 (0.15, 3.73) |
| Thrombosis, no diagnostic procedure, % | 36 (13%) | 74 (20%) | 0.60 (0.38, 0.95) |
| Angioplasty, stenosis 350% no thrombosis, % | 93 (33%) | 103 (28%) | 0.89 (0.64, 1.24) |
| Angioplasty, stenosis <50% no thrombosis, % | 2 (1%) | 3 (1%) | NA |
| Infection, % | 16 (6%) | 19 (5%) | 1.41 (0.63, 3.15) |
| Failure to use graft by 12 weeks in prevalent patient, % | 4 (1%) | 8 (2%) | 0.60 (0.14, 2.56) |
| Procedure for other reason, %c | 7 (3%) | 9 (2%) | 0.34 (0.18, 1.83) |
| Stenosis ≥50% with or without thrombosis, % | 157 (56%) | 187 (51%) | 0.90 (0.70, 1.14) |
| Secondary outcomes | |||
| cumulative graft failure, % | 143 (51%) | 191 (52%) | 0.91 (0.71, 1.16) |
| Death, % | 110 (39%) | 110 (28%) | 1.04 (0.78, 1.40) |
| Cumulative graft failure or death, % | 185 (66%) | 241 (65%) | 0.87 (0.70, 1.08) |
aHazard ratio was obtained from a Cox model that adjust for randomization group and baseline variables including age, diabetes history, diastolic BP, cardiovascular disease, cerebrovascular disease, peripheral arterial disease, smoking status, albumin, and use of angiotensin converting enzyme inhibitor and/or angiotensin receptor blocker. The model was also stratified by access location and clinical center.
bP > 0.05 for the interaction effect between intervention and use of aspirin at baseline for all endpoints.
cProcedures done for other reasons. For the group on aspirin at baseline: access ligation for hand ischemia (four patients), angioplasty, or access ligation for central vein stenosis (one patient), surgical revision for peudoaneursym without stenosis (one patient), and ligation for uncontrolled bleeding without angiogram reported (one patient). For the group not on aspirin at baseline: access ligation for hand ischemia (three patients), angioplasty or access ligation for central vein stenosis (three patients), surgical revision for peudoaneursym without stenosis (two patients), and ligation for uncontrolled bleeding without angiogram reported (one patient).