Characteristics of left ventricular and cardiac hemodynamic remodeling after on-pump or off-pump coronary artery bypass grafting

Abstract

Aim. To study the comparative dynamics of left ventricular (LV) remodeling after on-pump and off-pump coronary artery bypass grafting.Materials and methods. The study included 129 patients with verified coronary artery disease (CAD) who underwent coronary artery bypass grafting (CABG) with cardiopulmonary bypass (on-pump CABF) or beating heart surgery (off-pump CABG). All patients underwent transthoracic echocardiography (TTE) and volumetric compression oscillometry (VCO) before surgery, as well as one week and four months after it. The results were compared in groups divided according to the surgical technique and the presence of previous myocardial infarction using variation series, the Tukey’s post-hoc test, the Pearson correlation coefficient, and the Spearman’s rank correlation coefficient.Results. According to TTE data, no difference in hemodynamic parameters between the groups in the postoperative period was noted. According to VCO data, a significant difference was revealed in the off-pump group without previous MI one week after surgery: an increase in cardiac output (CO) (p < 0.001), an increase in stroke volume (SV) and stroke index (SI) (p = 0.005), LV power (LVP) (p = 0.015), and also a rise in cardiac index and LVP four months after the surgery. In the on-pump group of patients with previous MI a week after CABG, a decrease in the LVP (p < 0.001) and dynamic changes of energy expenditure (p < 0.001) were observed. The correlation analysis revealed moderate correlations between the inotropic parameters of cardiac hemodynamics SV, SI, CO, LVP and blood pressure (BP) (rπ = 0.33–0.47; p < 0.001) and strong correlations between SV, SI, CO, LVP and ejection fraction (EF) (rπ = 0.63–0.68; p < 0.001).Conclusion. Seven days after the off-pump CABG, an improvement in some hemodynamic parameters and all inotropic parameters of the heart was revealed compared with the on-pump group. Four months after the off-pump surgery, positive hemodynamic remodeling was observed compared with the postoperative period after the onpump CABG.