Table II.

Major bleeding and thrombotic complications in unmatched and propensity score-matched patients undergoing carotid endarterectomy (CEA) in the Vascular Quality Initiative (VQI), stratified by dual antiplatelet therapy use

	Unmatched			Propensity score matched
Crude outcomes	Aspirin alone (n = 21,624), No. (%)	Clopidogrel + aspirin (n = 7059), No. (%)	P valuea	Aspirin alone (n = 4548), No. (%)	Clopidogrel + aspirin (n = 4548), No. (%)	P value
Major bleeding complications
RTOR for bleeding	158 (0.7)	84 (1.2)	<.001	32 (0.7)	59 (1.3)	.004
Thrombotic complications
TIA or stroke	280 (1.3)	72 (1.0)	.069	72 (1.6)	39 (0.9)	.002
Ipsilateral TIA or stroke	209 (1.0)	59 (0.8)	.322	56 (1.2)	34 (0.8)	.02
Any stroke	180 (0.8)	47 (0.7)	.171	44 (1.0)	27 (0.6)	.04
Post-op MI	164 (0.8)	84 (1.2)	.001	35 (0.8)	43 (1.0)	.4
Death	44 (0.2)	18 (0.3)	.417	14 (0.3)	9 (0.2)	.3
Stroke/death	206 (1.0)	57 (0.8)	.266	53 (1.2)	33 (0.7)	.03

MI, Myocardial infarction; RTOR, return to operating room; TIA, transient ischemic attack.

^aP values for categorical variables were determined using the χ² test.