Introduction
The prevalence of coronary artery disease is rapidly increasing [1].
In China, the prevalence is estimated at 4.6 per thousand residences of
all ages, effecting 5 million adults [2]. Coronary artery disease is
the most major cause of left ventricular dysfunction, commonly defined
in terms of reduced
left
ventricular ejection fraction (<50%) [2-4]. Coronary
artery bypass graft (CABG) is the common type of cardiac surgery
worldwide. Paradoxically, there is strong evidence from recent studies
that left ventricular dysfunction is a predictor of early mortality and
a leading cause of high healthcare cost after conventional coronary
artery bypass grafting (cCABG), posing a great burden on both patients
and society [5, 6].
Despite advances in surgical techniques, the management of patients with
decreased left ventricular ejection fraction is still challenging. Off
pump coronary artery bypass surgery (OPCAB) is an attractive alternative
in patients with impaired left ventricular function, comparing with
cCABG. The benefits of OPCAB theoretically were centered around the
avoidance of cardiopulmonary bypass and aortic manipulation, which were
endorsed by observations of avoiding the negative effects of
cardiopulmonary bypass on markers of inflammation, coagulation,
micro-embolization, thermoregulation, acid based balance, and regional
perfusion [7-9]. Substantially, positive short- and middle- term
outcomes of reducing morbidity and mortality were observed in study
[10, 11]. In light of these advantages, OPCAB now accounts for more
than 50% of all CABG operations in China and other developing countries
[12].
However, lifting and rotating the heart during OPACB potentially alter
such hemodynamics as left ventricular end-diastolic pressure, right
atrial pressure and cardiac outputs, as a result of the worsened
preservation of interventricular septal movement, the activation of
inflammatory mediators and the non-physiologic ventricular geometry of
the empty heart impeding collateral flow to ischemic areas [13]. The
decrease in short-term mortality seen with OPCAB may be negated by
reduced long-term graft patency, increased needs for repeat
revascularization procedures and inferior long-term survival compared
with CCAB in left ventricular dysfunction patients [14]. The
clinical evidence base surrounding OPCAB in this population remains
equivocal, ridden with biased
observational studies, and relatively small randomized trials [15].
Given these concerns, it may seem still challenging for surgeons to take
OPCAB procedure in patients with left ventricular dysfunction.
To address some of the evidence gaps regarding prevailing practices in
management of patient with left ventricular dysfunction, we conducted
present study to compare the short and long-term outcomes in patients
with different ejection fractions undertaken OPCAB by the same surgeons
team, using the real-life registry database with an analysis of a
propensity score matching.