The AHA Guidelines and Scientifi c Statements Handbook
Class IIb
Patients undergoing CABG who have mild aortic ste-
nosis (mean gradient less than 30 mm Hg or Doppler
velocity less than 3 m/s) may be considered candi-
dates for aortic valve replacement if risk of the com-
bined procedure is acceptable. (Level of Evidence: C)
The incidence of CASHD in patients with angina
pectoris who are undergoing AVR for aortic stenosis
is 40% to 50% and drops to 20% in patients without
chest pain [93,94]. The incidence of CASHD in
patients with aortic insuffi ciency is less than that
seen with aortic stenosis [93]. Mitral stenosis patients
coming for valve surgery rarely have CASHD, as
this lesion is seen most frequently in middle-age
women [1].
Mitral regurgitation (MR) occurring with struc-
turally normal leafl ets in patients with CASHD is
usually caused by ischemia to the left ventricle
causing papillary muscle-induced leafl et tethering
[1]. Intervention on the mitral valve in these
instances is predicated on the fi ndings on preopera-
tive and intraoperative transesophageal echocar-
diography and size of the left atrium. With 1+ − 2 +
MR and a left atrium of normal size (<4.5 cm),
revascularization should proceed without direct
valve inspection and intervention [1]. If the MR is
3 + − 4 + and the left atrium is enlarged, mitral valve
repair is encouraged in addition to CABG [1]. Con-
troversy exists somewhat in the case of ischemic
moderate MR with normal leafl et morphology and
a normal-sized left atrium [95,96].
The operative mortality for patients undergoing
AVR who have ungrafted CASHD (lesions ≥50% on
arteriography) approaches 10%, while those patients
having AVR and concomitant CABG for CASHD
have an operative mortality approaching that of
AVR alone [97].
It is generally agreed that the risk of adding CABG
to a valve operation increases the operative mortal-
ity over that of an isolated valve procedure. The
addition of a valve operation to a CABG increases
operative risk and risk of stroke [98].
Reoperation
Mortality rates for reoperative CABG are greater
than that for primary surgery. However, reoperative
CABG is often the best treatment strategy for many
patients with recurrent myocardial ischemia. To
date, no randomized studies comparing treatment
options for patients with previous bypass surgery
exist. Observational studies have demonstrated that
reoperation improved the survival rate and symptom
status of patients with late vein graft stenoses, par-
ticularly if a stenotic vein graft subtended the LAD
coronary artery [1,99]. Other studies have identifi ed
a positive stress test as a factor that incrementally
defi nes a group of patients at high risk without
repeat surgery [1,99]. PCI of late (>5 years old)
atherosclerotic vein grafts is less successful than in
native coronaries with atherosclerosis [1].
The use of the IMA to LAD appears to decrease
reoperative rates, and vein graft failure may be
delayed by platelet inhibitors and statin therapy
[99].Concomitant PVD
The presence of clinical and subclinical PVD is a
strong predictor of increased in-hospital and long-
term mortality rate in patients undergoing CABG
[1]. The coexistence of PVD and CASHD is well-
established; patients undergoing peripheral vascular
surgery should be screened for CASHD [1].Poor left ventricular function
LV function is an important predictor of early and
late mortality after CABG. Studies demonstrate
mortality rates in patients with depressed LV func-
tion undergoing CABG exceeding the risk of CABG
in patients with normal LV function by 2- to 3-fold
[1,100–102]. However, the benefi cial effects of sur-
gical revascularization in the patient with ischemic
heart disease and LV dysfunction are clearly evident
when compared with medical treatments in terms of
symptom relief, exercise tolerance, and long-term
survival [100,103,104]. CABG is recommended in
patients with severe multivessel disease and poor
ventricular function but with a large amount of
viable myocardium [1].Transplant patients
Typically, CABG is not a good option for trans-
planted hearts with transplant vasculopathy because
of the diffuse, distal involvement of the process
[105]. Retransplantation is the only defi nitive
therapy for advanced allograft vasculopathy [1].
The safety and effi cacy of CABG in renal and
liver transplanted patients has been described
[106,107].