Abstract 3115: Prolonged QRS Duration is a Significant Predictor of Low Cardiac Output Syndrome Development After Isolated Coronary Artery Bypass Grafting in Patients with Impaired Left Ventricular Systolic Function
Aims: Abnormal left ventricular systolic function places patients at greater risk for developing low cardiac output syndrome (LCOS) after isolated coronary artery bypass grafting (CABG). In patients with this form of ventricular function impairment, prolonged QRS duration (QRSd) is associated with adverse hemodynamic effects. The purpose of this study was to determine whether prolonged QRSd (≥ 120 ms) is an independent predictor of LCOS in patients with low left ventricular ejection fraction (LVEF) who undergo isolated CABG.
Methods: Clinical, operative and outcome data from 190 consecutive patients (mean age, 62 ± 9 years) with LVEF <50% as determined by ventriculography who underwent isolated CABG were retrospectively analyzed. For all patients, preoperative QRSd was determined. LCOS was the primary outcome investigated.
Results: Fifty-seven (30%) patients developed LCOS. Compared to the subgroup without LCOS, the subgroup with this syndrome had significantly higher proportions of patients with LVEF < 30% (8% vs. 46%, respectively; p <0.00001) and prolonged QRSd (9% vs. 49%, respectively; p <0.00001). As well, the group that developed LCOS had a longer mean QRSd (117 ± 25 ms vs. 102 ± 17 ms, respectively; p = 0.00003) and a significantly higher frequency of adverse postoperative outcomes (32% vs. 15%, respectively; p = 0.016). The hospital stay was significantly longer in the subgroup with LCOS than in the subgroup without. Multivariate logistic regression analysis identified prolonged QRSd (OR = 7.349; 95% CI, 3.025–17.852) as the most significant predictor of LCOS. LVEF < 30% (OR = 5.073; 95% CI, 2.040–12.617), preoperative diuretic therapy (OR = 2.400; 95% CI, 1.043–5.522) and preoperative risk score (European System for Cardiac Operative Risk Evaluation [EuroSCORE]) (OR = 1.153; 95% CI, 1.002–1.326) were also identified as independent predictors of LCOS.
Conclusion: In patients with impaired left ventricular systolic function, prolonged QRSd is a highly significant predictor of LCOS development after isolated CABG.