Study Population and Preoperative Characteristics
A total of 307 patients underwent OPCAB were enrolled and stratified by
LVEF before matching. The two propensity score-matched groups consisted
of 40 LVD and 120 NLVF patients, respectively. The demographic and
preoperative characteristics of the patients both pre- and post-matching
are shown in Table 1. Compared with LVD group, the NLVF group had
significantly smaller proportion of smoker (34.9% vs. 51.9%;p =0.028), preoperative IABP (5.1% vs. 25.0%,p <0.001) and NYHA functional class III/IV (22.4% vs.
61.5%, p <0.001) before matching.
The matched-pairs had similar baseline characteristics expect for the
baseline LVEF, which was higher in the NLVF group (62.8±6.70% vs.
35.8±5.98%, p<0.001), indicating that the propensity model
had successfully served to remove the imbalance in distribution of a
number of prognostic factors. Patients with normal LVEF had slightly
higher proportion of obesity and CCS class3/4 angina compared to
patients in NLVF group, but no significant difference were found (48.8%
vs. 40.0%, 22.5% vs.17.5%, both p >0.05).