CHOICE OF MANAGEMENT METHOD OF MYOCARDIAL REVASCULARIZATION IN PATIENTS WITH LOW LEFT VENTRICULAR EJECTION FRACTION (<35 %): A RANDOMIZED PROSPECTIVE STUDY

Abstract

Purpose. Make a comparative assessment of supportive methods of myocardial revascularization in ischemic heart disease patients with low left ventricular ejection fraction (<35 %) conducted under CPB with cardioplegic cardiac arrest and on a beating heart combined with intraoperative use of IABP or levosimendan. Materials and methods. The study included 90 patients with coronary artery disease and left ventricular ejection fraction <35 %, which was performed CABG under normothermic CPB. Patients were randomized into 4 groups: IABP+CP (CPB with cardioplegia and IABP) (n=30), IABP+CPB (beating heart on a parallel CBP and IABP) (n=14), LS+CP (CBP with cardioplegia and levosimendan) (n=30), LS+CBP (beating heart on a parallel CBP and IABP) (n=16). The primary endpoint wastroponinI.Hemodynamic parameters, the markers of myocardial damage and heart failure, postoperative complications, length of ICU stay, length of hospital stay was evaluated. Results. In LS+CP and LS+CBP groups was revealed reduction in blood pressure (p=0.002 and p=0.013 respectively) and increase in heart rate (p=0.0008 and p=0.0002 respectively) before CBP in comparison with IABP. The average area under the curve (AUC) of troponin I concentration in LS+CP group was less than in IABP+CP group: 11.75 (6.28–13.29) ng/ml vs 24.43 (12.52–27.88) ng/ml, p=0.013. In LS+CP group was revealed decrease in length of ICU stay (2 (2–3) days) compared with IABP+CP group (4 (3–4) days, p=0.0002) and IABP+CBP group (4 (3–6) days, p=0.0008). Preoperative BNP concentration ≥203 pg/mL was a predictor of necessity for inotropic support with sensitivity 60 % (95 % CI 47.1–72.0) and specificity 93.75 % (95 % CI 69.8–99.8) (AUC 0.728; p=0.0001). Preoperative NTproBNP concentration ≥8.24 fmol/L was a predictor of necessity for inotropic support in the postoperative period with sensitivity 77.78 % (95 % CI 64.4–88.0) and specificity 66.67 % (95 % CI 38.4–88.2) (AUC 0.745; p=0.0012). In singlefactor regression analysis the independent effect on necessity for inotropic support in the early postoperative period exert the concentration of preoperative BNP (OR=1.01; 95 % CI 1.001–1.014; p=0.033). Belonging to LS+CP group reduces the risk of ICU stay for more than 3 days on 72 % (OR=0.28; 95 % CI 0.09–0.82; p=0.021). In multivariate regression analysis, a risk factor for 30-day mortality was the concentration of troponin I on the second postoperative day (OR=1.15; 95 % CI 1.03–1.27; p=0.010) and the preoperative concentration NTproBNP was a risk factor for the 1 year mortality (OR=1.02; 95 % CI 1.001–1.032; p=0.006). 6 hours CPK level after CBP was a predictor of atrial fibrillation development in the early postoperative period (OR=1.003; 95 % CI 1.001–1.005; p=0.003) and prolonged hospital stay for more than 14 days (OR=0.996; 95 % CI: 0.994–0.999; p=0.007) Conclusion. CABG on a beating heart under CPB in ischemic heart disease patients with low left ventricular ejection fraction (regardless of the hemodynamic support method) does not lead to significant decrease in serum concentration of Troponin I in the postoperative period. Intraoperative levosimendan infusion together with cardioplegic cardiac arrest improves early postoperative period, which is expressed in significant reduction in ICU stay. Thus, the most preferred method to support myocardial revascularization in ischemic heart disease patients with low left ventricular ejection fraction is combination of a standard methodology for CABG with cardioplegic myocardial protection accompanied by intraoperative infusion of levosimendan. Key words: cardiopulmonary bypass; coronary artery bypass surgery; beating heart; IABP; levosimendan.