Persistent ventricular asynchrony after coronary artery bypass surgery predicts cardiac events.

AIM

The aim of this study was to identify echocardiographic LV systolic and diastolic measurements that predict clinical events post-coronary artery bypass graft (CABG) surgery.

METHODS

We collected data from 27 patients (age 70 +/- 7 years) who underwent elective CABG, before and within 6 weeks after surgery. LV systolic function was assessed by conventional echocardiographic parameters. A number of LV filling measurements were also made, which included total isovolumic time (t-IVT), Tei index, and restrictive filling pattern. Postoperative cardiac events were death or hospitalization for chest pain, breathlessness, or arrhythmia.

RESULTS

Patient's follow-up period was 17 +/- 10 months. Of the 27 patients (age 70 +/- 7 years, 22 male), 10 had postoperative cardiac events. LV ejection fraction (EF) and fractional shortening (FS) were lower (P = 0.01, and P = 0.007, respectively), t-IVT longer (P < 0.001), and Tei index was higher (P < 0.001) preoperatively in patients with events compared to those without. The same differences between groups remained after surgery; EF (P = 0.002), FS (P = 0.002), t-IVT (P < 0.001), and Tei index (P < 0.001). T-IVT was the only preoperative predictor of events (P = 0.038) but its postoperative value as well as that of FS predicted events (P = 0.034, and P = 0.042, respectively). T-IVT of 12.2 s/min and FS of 26% were 80% sensitive and 88% specific for predicting postoperative events.

CONCLUSION

Despite successful surgical revascularization residual impairment of LV systolic function and persistent asynchrony in the form of prolonged t-IVT are associated with postoperative events. Since these abnormalities remained despite full medical therapy, they may thus suggest a need for electrical resynchronization therapy.