Table I.
Unmatched and propensity score-matched comparison of demographics and operative factors in patients undergoing carotid endarterectomy (CEA) in the Vascular Quality Initiative (VQI), stratified by dual antiplatelet therapy use
| Characteristica |
Unmatched
|
Propensity score matched
|
||||
|---|---|---|---|---|---|---|
| Aspirin (n = 21,624) | Aspirin + clopidogrel (n = 7059) | P value | Aspirin (n = 4548) | Aspirin + clopidogrel (n = 4548) | P value | |
| Demographics | ||||||
| Gender | ||||||
| Male | 12,870 (59.5) | 4460 (63.2) | <.001 | 2860 (62.9) | 2858 (62.8) | .965 |
| Female | 8754 (40.4) | 2598 (36.8) | ||||
| White race | 20,392 (94.3) | 6515 (92.3) | <.001 | 4200 (92.4) | 4187 (92.1) | .611 |
| Age, years | 70.4 ± 9.1 | 69.6 ± 9.4 | <.001 | |||
| Age category | ||||||
| <40 years | 15 (0.1) | 8 (0.1) | .257 | 3 (0.1) | 5 (0.1) | .479 |
| 40–49 years | 290 (1.3) | 137 (1.9) | <.001 | 60 (1.3) | 81 (1.8) | .075 |
| 50–59 years | 2355 (10.9) | 904 (12.8) | <.001 | 509 (11.2) | 529 (11.6) | .510 |
| 60–69 years | 7027 (32.5) | 2364 (33.5) | .123 | 1544 (34.0) | 1505 (33.1) | .386 |
| 70–79 years | 8255 (38.2) | 2541 (36.0) | .001 | 1720 (37.8) | 1698 (37.3) | .634 |
| 80–89 years | 3518 (16.3) | 1051 (14.9) | .006 | 685 (15.1) | 691 (15.1) | .861 |
| ≥89 years | 164 (0.8) | 54 (0.8) | .956 | 27 (0.6) | 39 (0.9) | .138 |
| Ipsilateral neurologic symptoms | 4792 (22.2) | 2193 (31.2) | <.001 | 1338 (29.4) | 1317 (29.0) | .628 |
| History of neck radiation | 291 (1.4) | 93 (1.3) | .863 | 64 (1.4) | 67 (1.5) | .790 |
| Hypertension | 19,054 (88.2) | 6414 (90.9) | <.001 | 4177 (91.8) | 4132 (90.9) | .093 |
| Coronary artery disease | 5645 (26.1) | 2772 (39.3) | <.001 | 1673 (36.8) | 1640 (36.1) | .472 |
| Prior CABG or coronary intervention | 6482 (30.3) | 3441 (49.4) | <.001 | 2224 (48.9) | 2212 (48.6) | .801 |
| Congestive heart failure | 1820 (8.4) | 773 (11.0) | <.001 | 480 (10.6) | 505 (11.1) | .399 |
| Smoking (prior or current) | 16,509 (76.5) | 5395 (76.5) | .881 | 3492 (76.8) | 3479 (76.6) | .820 |
| COPD | 4382 (20.3) | 1591 (22.6) | <.001 | 1008 (22.2) | 1018 (22.4) | .801 |
| Diabetes | 7068 (32.7) | 2694 (38.2) | <.001 | 1752 (38.5) | 1742 (38.3) | .829 |
| Creatinine ≥1.8% | 1045 (5.0) | 409 (5.9) | .001 | 234 (5.3) | 243 (5.5) | .688 |
| Dialysis | 172 (0.8) | 84 (1.2) | .002 | 55 (1.2) | 59 (1.3) | .706 |
| Pre-op medication regimen | ||||||
| β-blockers | 13,700 (63.4) | 4865 (69.0) | <.001 | 3044 (66.9) | 3033 (66.7) | .807 |
| Statin use | 17,182 (79.5) | 6025 (85.4) | <.001 | 3893 (85.6) | 3896 (85.7) | .929 |
| Anticoagulation | 1139 (9.0) | 146 (3.1) | <.001 | 147 (3.2) | 142 (3.1) | .765 |
| Stress test | ||||||
| Not done | 13,828 (64.2) | 4379 (62.3) | <.001 | 2904 (63.9) | 2870 (63.1) | .657 |
| Normal result | 6002 (27.8) | 1879 (26.7) | 1207 (26.5) | 1218 (26.8) | ||
| Abnormal result | 1726 (8.0) | 776 (11.0) | 437 (9.6) | 460 (10.1) | ||
| Operative factors | ||||||
| Drain | 6812 (39.9) | 2867 (46.1) | <.001 | 2026 (44.6) | 2085 (45.8) | .214 |
| Heparin | 21,366 (99.0) | 34,047 (98.9) | .741 | 4492 (98.8) | 4491 (98.8) | .925 |
| Protamine | 12,742 (59.1) | 4800 (68.2) | <.001 | 3104 (68.3) | 3108 (68.3) | .928 |
| Dextran | 2893 (13.4) | 859 (12.2) | .009 | 597 (13.1) | 619 (13.6) | .498 |
| Type | ||||||
| Conventional | 18,817 (87.5) | 6100 (87.0) | .308 | 3905 (85.9) | 3871 (85.1) | .311 |
| Eversion | 2698 (12.5) | 912 (13.0) | 643 (14.1) | 677 (14.9) | ||
| Shunt | 11,017 (51.1) | 4029 (57.3) | <.001 | 2560 (56.3) | 2519 (55.4) | .387 |
| Patch | 19.198 (88.9) | 6320 (89.9) | .031 | 4127 (90.7) | 4098 (90.1) | .301 |
| Post-op hypertensionb | 3250 (15.1) | 1145 (16.3) | .015 | 728 (16.0) | 775 (17.0) | .185 |
| Post-op hypotensionb | 2247 (10.4) | 785 (11.2) | .082 | 487 (10.7) | 491 (10.8) | .892 |
CABG, Coronary artery bypass graft; COPD, chronic obstructive pulmonary disease.
a
Categorical data are shown as number (%) and continuous data as mean ± standard deviation.
b
Requiring intravenous medication.