Early Outcomes of Coronary Artery Bypass Grafting in Patients with Low Ejection Fraction

Abstract

Background: Patients with low ejection fraction (EF) are at a higher risk for postoperative complications and mortality. Our objective was to assess the effect of low EF (<40%) on early clinical outcomes after coronary artery bypass grafting (CABG) and to determine the predictors of mortality. Methods: From June 2017 to February 2019, 170 consecutive patients underwent CABG. There were 120 patients with low EF (<40%; 37.49 ± 2.89%); 94 were men (78.3%), and the mean age was 55.83 ± 8.04 years. Fifty patients had normal EF (> 40; 57.90 ± 2.27 %), 41 were men (82.0%), and the mean age was 54.30 ± 7.01 years and used as a control group. Results: Overall 30-day mortality was 10/120 patients (8.3%). Factors associated with higher mortality were females ( 70.0% vs. 17.3%, P<0.001); older age (61.40 ± 7.01 vs. 55.32 ± 7.97 years, P=0.025); diabetes mellitus (100% vs. 51.8%; P=0.003); longer cardiopulmonary bypass time (148.70 ± 40.12 vs. 108.49 ± 36.89 min; P=0.012); longer cross clamp time (88.19 ± 31.94 vs.64.77 ± 22.67 min; P=0.049), longer total operative time (6.82 ± 1.03 vs 5.38 ± 0.95 hours; P=0.001); intra-aortic balloon pump (IABP) insertion (90.0% vs. 10.9%; P<0.001); intra-operative complications (60% vs. 1.8%, P<0.001); ventricular tachycardia and ventricular fibrillation (30% and 50% vs. 4.5% and 5.5% respectively; P=0.002 for both); myocardial infarction (70% vs 11.8%, P<0.001), and lower postoperative ejection fraction (21.46 ± 1.93 vs 40.30 ± 8.19 %, P<0.001). In patients with low EF, postoperative NYHA and CCS angina class have improved compared to the preoperative levels (1.50 ± 0.61 vs. 3.31 ± 0.56; p< 0.001 and 1.38 ± 0.52 vs. 3.11 ± 0.55; p< 0.001 respectively) Conclusion: Patients with low EF have a higher risk of morbidity and mortality; however, the clinical and echocardiographic parameters improve over time. Therefore, CABG remains a viable option in selected patients with low EF. Factors affecting our 30-days mortality were related to the severity of the disease. Article History https://doi.org/10.35810/ects.v1i2.43 BMI= body mass index, EF= ejection fraction, LVEDD = left ventricular end diastolic diameter, LVESD= left ventricular end systolic diameter, CPB= cardiopulmonary bypass, ACC= aortic cross clamp, DC= defibrillating cardiac ICU= intensive care unit, IABP= intra-aortic balloon pump, NYHA= New York Heart Association, EF= ejection fraction, LVEDD = left ventricular end diastolic diameter, LVESD= left ventricular end systolic diameter, AF= atrial fibrillation, V Tach= Ventricular tachycardia, VF= ventricular fibrillation. Aljunaidy L.