Influence of wall motion score on mortality after coronary bypass surgery in the CABG-patch trial

Background: It was hypothesized that a wall motion score (WMS) of ≤16% determined by chordal analysis (WMS=% of chords analyzed with normal or hyperkinetic motion) from a right anterior oblique (RAO) left ventriculogram would be a predictor for perioperative (30-day or in-hospital) or long-term mortality in patients from the CABG-Patch Trial. Methods and results: One hundred and eighty-nine patients from the trial with a LVEF of ≤36% were retrospectively studied. Patients were divided into two groups according to a WMS of ≤16% (n=81) or >16% (n=108), respectively, calculated from a preoperative RAO ventriculogram. There was no difference in EF between the two groups (26.5±5.5 vs. 27.8±5.3%, respectively). Eight (9.9%) versus three (2.8%) patients died perioperatively in the low versus the high WMS group, respectively. The relative risk for perioperative death in the low WMS group was 3.6 (P<0.04). Kaplan–Meier estimates of cumulative survival did not reveal any statistical difference between the two groups over 4 years (P=0.11). Subgroup analysis revealed that patients with a WMS of ≤16% had a better survival when treated with an ICD at the time of surgery compared to those not treated with an ICD (P=0.046). Conclusions: These data indicate that poor LV function, as assessed by a WMS of ≤16%, can identify a subgroup of low EF patients who are at increased risk for perioperative mortality after bypass surgery. Conversely, long-term estimates of survival in patients with WMS ≤16 and >16% were not significantly different, although subgroup analysis revealed that patients with a WMS ≤16% may benefit from implantation of an ICD at the time of surgery.