Discussion
To the best of our knowledge, this study provides an up-to-date and
unique view of the association between preoperative LVEF and long-term
outcomes in patients after OPCAB surgery. In present study, we performed
a propensity score matching using a single-center surgery registry data
to investigate the disparities of long-term survival between LVD and
NLVF group, and the main findings of our study were as follows: 1) The
proportion of perioperative inotrope usage were significantly greater in
LVD group than NLVF patients, while the proportion of constructed three
or more distal anastomoses were more in NLVF group, indicating the
surgery management was more challenging for LVD patient intra-OPCAB; 2)
the risk of post-operative left heart failure was higher in LVD patient,
compared with NLVF patients, and 3) both early postoperative and
long-term outcomes are similar regardless of preoperative LVEF. These
findings confirm the efficacy and safety of OPCAB utilization in
patients with reduced left ventricular ejection fraction. Furthermore,
these findings highlight the importance of initiatives to develop a
tailored surgery strategy for patients with LVD that is able to improve
surgical outcomes and optimize the long-term survival.
With the highly prevalent of coronary artery disease globally, and
increasing of comorbid with impaired LVEF, cardiac surgeons are facing
more patients with poor pre-condition. LVEF is the most widely used
clinical indicator of left ventricular systolic function and related the
cardiovascular risk in patient with heart failure. Results from CHARM
showed the risk of all-causes mortality and major cardiovascular event
were inversely and linearly associated with LVEF [16]. The risk of
stroke was more than doubled in patients with LVEF<15%
[17]. OPCAB surgery avoids ischemic cardiac arrest during coronary
artery revascularization. A recent published study shows that OPCAB is a
safe and efficient choice for high risk patients with multiple organs
failure [18]. Given the improvement and advantages of OPCAB
procedure, more and more surgeons try to extend the suegery to high risk
patients, including female and Low LVEF patient [19, 20].
Despite enthusiasm for OPCAB on the part of surgeons, widespread
adoption in China has been slower than anticipated. It is due, in part,
to a lack of definitive evidence whether OPCAB can be safe in LVD
patients. In a recent randomized control study, OPCAB and on-pump
techniques seemed to produce equivalent results, although OPCAB was
associated with a lower graft patency rate [21]. Given the
inconsistency of different report, the usage of OPCAB in LVD patients is
limited in real practice.
The major concern is high proportion of completed revascularization,
which reported to be an independent risk for all-cause mortality
(HR=1.8) [22]. ROOBY study and a meta-analysis demonstrated that
number of constructed distal anastomoses underwent OPCAB are lesser than
those underwent conventional CABG [14, 23]. Our study is in line
with above findings: the lower LVEF, the smaller proportion of
constructed 3 or more distal anastomoses (77.5% vs 92.5%,p =0.037). Meanwhile, the occurrences of complete
revascularization are not significantly different between groups (82.5%
vs 87.5%, p =0.579). Preoperative IABP and using vascular shunt
during operation to construct distal anastomoses can help patients with
reduced LVEF to complete revascularization. Our results have significant
implications for clinical practice. OPCAB can be safely undergone for
patients with left ventricular dysfunction if well preoperative and
intraoperative management. Surgeons should attempt to personalized
management strategy for those patients.