Lrs. Dewar et al., UNILATERAL VERSUS BILATERAL INTERNAL MAMMARY REVASCULARIZATION - SURVIVAL AND EVENT-FREE PERFORMANCE, Circulation, 92(9), 1995, pp. 8-13
Background The influence of unilateral (UL) and bilateral (BL) mammary
artery revascularization, within age groups <less than or equal to >6
0 years and >60 years, on patient survival, ischemic-related events, a
nd interventional management was studied in 1142 patients who had coro
nary artery bypass graft surgery between 1984 and 1992. Methods and Re
sults UL revascularization was performed in 765 (67%) and BL in 377 (3
3%) patients with supplemental vein grafts. The overall early and hosp
ital mortality rate was 2.7%. For UL in the age group less than or equ
al to 60 years, it was 1.1%; for BL <less than or equal to >60 years,
1.3% (P=NS); for UL >60 years, 4.3%; and for BL >60 years, 2.8% (P=NS)
. Twenty-five preoperative patient characteristics representing demogr
aphics, extent of disease, concomitant disease, ventricular dysfunctio
n, previous surgery, and status did not differentiate the patient grou
ps (P=NS). Patient survival at 5 years was not different: 94% for UL <
less than or equal to >60 years, 95% for BL less than or equal to 60 y
ears, 91% for UL >60 years, and 56% for BL >60 years (P=NS). The freed
om from ischemic-related events was not different at 5 years (P=NS). T
he freedom from recurrent angina was 78% for UL <less than or equal to
>60 years, 88% for BL less than or equal to 60 years, 82% for UL >60
years, and 83% for BL >60 years (P=NS). The myocardial infarction free
dom was 98% for UL <less than or equal to >60 years, 96% for BL less t
han or equal to 60 years, 99% for UI, >60 years, and 97% for BL >60 ye
ars (P=NS). The freedom from sudden unexpected death and cardiac death
did not differentiate the groups (P=NS). The freedom from angioplasty
and reoperation did not differentiate the groups (P=NS). The freedom
from all ischemic-related and interventional events was 76% for UL <le
ss than or equal to >60 years, 84% for BL <less than or equal to >60 y
ears, 81% for UL >60 years, and 79% for BL >60 years (P=NS). A trend e
xists for less angina pectoris in the bilateral population <less than
or equal to >60 years, which reflects in the trend in the freedom from
overall events. Conclusions UL and BL mammary artery revascularizatio
ns have the same early mortality regardless of age but do not reveal a
ny advantage for BL revascularization at 5 to 7 years.