Single vs double antiplatelet therapy in acute coronary syndrome: Predictors of bleeding after coronary artery bypass grafting

Table 1 Patient demographic, pre-operative characteristics, operative data

	Group AASA	Group BASA + Clopidogrel	P
Age	67 ± 9.4	66.3 ± 10.1	0.71 (T-t)
Gender (M/F)	42/8	45/5	0.46 (P-χ2-t)
Weight (kg)	75.2 ± 13	76.4 ± 10.3	0.60 (T-t)
Hypertension	46/50 (92%)	50/50 (100%)	0.11 (F-t)
Dyslipidaemia	45/50 (90%)	45/50 (90%)	1 (F-t)
Diabetes	14/50 (28%)	18/50 (36%)	0.39 (P-χ2-t)
COPD	12/50 (24%)	8/50 (16%)	0.45 (F-t)
Renal failure	7/50 (14%)	4/50 (8%)	0.33 (P-χ2-t)
History of MI	28/50 (56%)	29/50 (58%)	0.5 (F-t)
History of CVA	4/50 (8%)	1/50 (2%)	0.36 (F-t)
Urgent surgery	22/50 (44%)	25/50 (50%)	0.34 (F-t)
EF%	56 ± 8.5	50 ± 9.5	0.04 (KW)/0.03 (LR)
LVEDV mL/m2	60.8 ± 10.4	62.6 ± 12.5	0.54 (KW)
No. of anastomoses	2.5 ± 0.8	2.5 ± 0.7	0.99 (P-χ2-t)
No. of grafts	2.5 ± 0.8	2.4 ± 0.7	0.99 (P-χ2-t)

T-t: T test; F-t: Fisher’s exact test; P-χ²-t: Pearson’s chi-square test; KW: Kruskal Wallis-test; ASA: Acetylsalycilic acid; COPD: Chronic obstructive pulmonary disease; CVA: Cardio-vascular accident; EF: Ejection fraction; LVEDV: Left ventricular end-diastolic volume.

Table 2 Preoperative hematologic and coagulation profile

	Group AASA	Group BASA + Clopidogrel	P (KW)
Hb (g/dL)	13.44 ± 0.2	13.42 ± 0.2	0.95
Hematocrit (%)	39.9 ± 0.6	39.3 ± 0.5	0.67
Platelet count (103/mm3)	247 ± 8.6	245 ± 0.2	0.83
PT (%)	80.3 ± 1.6	80.5 ± 1.7	0.95
PTT (%)	32.2 ± 0.7	31.8 ± 0.8	0.67
CT-INTEM	153 ± 16	179 ± 15	0.87
CFT-INTEM	57 ± 4	63 ± 7	0.28
Alpha angle-INTEM	81 ± 10	75 ± 8	0.49
MCF-INTEM	65 ± 4	63 ± 5	0.51
AUC-INTEM	6543 ± 520	6320 ± 731	0.65
CT-EXTEM	55 ± 6	58 ± 7	0.52
CFT-EXTEM	96 ± 8	102 ± 9	0.51
Alpha angle-INTEM	71 ± 6	66 ± 5	0.33
MCF-EXTEM	65 ± 6	61 ± 9	0.057
AUC-EXTEM	6529 ± 643	6177 ± 978	0.056

ASA: Acetylsalycilic acid; PT: Prothrombin time; PTT: Partial thromboplastin time; CFT: Clot formation time; MCF: Maximum clot firmness; AUC: Area-under-curve; KW: Kruskal Wallis-test.

Table 3 Postoperative measures of bleeding and blood product transfusions

	Group AASA	Group BASA + Clopidogrel	P
Major bleeding	6 (12%)	8 (16%)	0.77 (F-t)
Re-intervention	1 (2%)	0 (0%)	1.0 (F-t)
Chest tube output (12 h)	509 ± 234	539 ± 239	0.41 (KW)
PRBCs (U)	1 ± 1	0.9 ± 0.9	0.87 (KW)
FFP (U)	0.5 ± 2	0.5 ± 1.9	0.99 (KW)
PLTs (U)	0.7 ± 2.7	1 ± 2.5	0.35 (KW)

ASA: Acetylsalycilic acid; FFP: Fresh frozen plasma; PRBCs: Packed red blood cells; PLT: Platelets.

Table 4 Clinical outcomes

	Group AASA	Group BASA + Clopidogrel	P
AMI	1 (2%)	0%	0.5 (F-t)
IABP	3 (6%)	2 (4%)	0.5 (F-t)
Stroke	1 (2%)	0 (0%)	0.5 (F-t)
Renal failure	1 (2%)	1 (2%)	1.0 (F-t)
AF	12 (24%)	7 (14%)	0.15 (F-t)
MV (h)	8 ± 11	6 ± 2	0.22 (KW)
ICU stay (d)	1.8 ± 3.3 (Med 1)	1.4 ± 0.9 (Med 1)	0.77 (KW)
Mortality	1 (2%)	0 (0%)	0.5 (F-t)
MACE (death, stroke. AMI)	3 (6%)	0 (0%)	0.24 (F-t)

F-t: Fisher’s exact test; KW: Kruskal Wallis-test; ASA: Acetylsalycilic acid; AMI: Acute myocardial infarction; AF: Atrial fibrillation; MV: Mechanical ventilation; MACE: Major adverse cardiac events.

Table 5 Logistic multivariate analysis of factors related to bleeding risk

	Coefficient	OR	95%CI	P
Age	-0.14	0.87	0.73-1.03	0.11
Weight	-0.35	0.71	0.52-0.97	0.03
Gender (female)	-10.54	0.00003	0.06-3.9	0.04
EF	-0.02	0.98	0.83-1.16	0.81
AUC EXTEM	-0.0099	0.99	0.98-0.99	0.008
Aspirin only	-1.18	0.31	0.02-4.58	0.39

Odds ratios are adjusted for concomitant variables. EF: Ejection fraction; AUC: Area-under-curve.