michael s
(Michael S)
#1
The patients who gain most from surgery are those most at risk
from dying with medical therapy alone. Pertinent high-risk
characteristics included left main stem (LMS) disease, triple
vessel disease or double vessel disease that included a proximal
LAD lesion, and triple vessel disease associated with impaired LV
function. The VA study at 18 years^2 demonstrated superior
surgical survival throughout the 18 years, but was only
significant overall at 7 years (med. vs surg. survival 53% vs 79%
p = 0.007); benefit was much greater in the high risk group with
LMS stenosis >50%, single or double vessel disease with
impaired LV function, and triple vessel disease with LV EF <40%.
In 1988 ECSS^3 reported 12 year results demonstrating signifi-
cantly higher cumulative survival in the surgical group, notably
again in patients with 3 vessel disease (med. vs surg. survival
82% vs 94% (p = 0.0002) at 5 years and 68% vs 78% (p = 0.01) at
10 years). Proximal LAD disease >95% in two or three vessel
disease was an outstanding anatomical predictor of survival
(med. vs surg. survival at 10 years 65% vs 77% (p = 0.007)), again
with significant crossover into the surgery group. The CASS
study^4 demonstrated no difference in survival for any subset at 5
years, but did not include any patients with poor LV function,
LMS disease, angina greater than class 2, co-morbid disease or
unstable angina. It is therefore difficult to extrapolate data from
this trial to modern patient populations.
Combining results from seven of these early randomised trials
led to the publication of survival figures for 5, 7 and 10 years.^5
Medical vs surgical mortality for all patients was 15.8% vs 10.2%
(p = 0.0001) at 5 years, with attenuation of this benefit to a
mortality of 30.5% (med.) and 26.4% (surg.) (p = 0.03) at 10
years. Extension of life for all patients having surgery was 4.3
months at 10 years. High-risk patients once again benefited the
most from surgery, but in lower risk groups, a survival extension
for those with proximal LAD disease (14 months), triple vessel
disease (7 months) or LMS disease (19 months) was identified.
This survival benefit was independent of degree of LV
impairment or abnormal stress testing. Median survival for
patients with LMS disease was 13.1 years in the surgical group
and 6.2 years for those treated medically. The superior patency of
the LIMA graft compared with saphenous vein grafts has been
established beyond any doubt and additional survival benefit, up
to 18 years, has been demonstrated.^6
