TABLE 1.

Propensity score, pair-wise-matched sample of patients undergoing isolated off-pump (OPCAB) and on-pump (CCAB) coronary artery bypass graft surgery between 1996 and 2002 at the University Health Network – Toronto General Hospital

Variable	CCAB (n=503)	OPCAB (n=503)	P
Age, years*	63±10	63±10	0.6
Body surface area, m2*	1.92±0.2	1.91±0.2	0.3
Body mass index, kg/m2*	28±7	28±5	0.8
CBP time, min*	83±29	0	<0.001
Cross-clamp time, min*	60±22	0	<0.001
Female sex, %	23	26	0.4
Left ventricular grade
1	45	45
2	35	34
3	18	19
4	2	2	0.9
Surgical priority
Elective	52	55
Urgent	47	45
Emergent	0.2	0.2	0.8
Recent myocardial infarction†	17	18	0.6
New York Heart Association classification
I	9	9
II	16	18
III	18	18
IV	58	56	0.8
Number of diseased vessels
1	14	16
2	29	28
3	57	56	0.7
Left main disease	20	20	1.0
Redo coronary artery bypass graft surgery	3.6	3.6	1.0
Renal insufficiency	6.6	6.2	0.8
Congestive heart failure	6.6	7.0	0.8
Diabetes	30	30	1.0
Peripheral vascular disease	34	36	0.6
Hypertension	58	56	0.4
Chronic obstructive lung disease	4	4	1.0
Preoperative stroke/TIA	9.2	10	0.7
Year of operation
1996–1998	9	13
1999–2000	65	62
2001–2002	26	26	0.1
Number of distal anastomoses
1	5.2	10
2	23	13
3	36	33
4	29	18
5	6	3	<0.001
Number of grafts*	3.1±1.0	2.6±1.0	<0.001
Coronary system grafted
Left anterior descending artery	97	96	0.7
Circumflex coronary artery	62	61	0.7
Right coronary artery	38	39	0.7
Left internal thoracic artery	89	88	0.8
RITA	5.2	8.0	0.07
LITA + RITA	4.6	7.4	0.06

*Reported as mean ± SD;

^†Within one month before surgery. CBP Cardiopulmonary bypass; LITA Left internal thoracic artery; RITA Right internal thoracic artery; TIA Transient cerebral ischemic attack