Abstract 12107: Worsening of Mitral Regurgitation During Off-pump Coronary Artery Bypass Grafting Causes Hemodynamics Deterioration by Dislocation of Beating Heart in Patients With Ischemic Heart Disease

Abstract

Introduction: Worsening of mitral regurgitation (MR) during off-pump coronary artery bypass grafting (OPCAB) is one of the predictors, which is often observed during elevation and dislocation of the beating heart in patients with ischemic heart disease (IHD). It is considered that morphological changes of mitral valve complex and worsening of MR cause the hemodynamic deterioration during OPCAB. However, it remains unclear whether the worsening of MR causes the hemodynamic deterioration during OPCAB. Hypothesis: The dislocation of the beating heart during OPCAB leads to exacerbation of ischemic MR, and the worsening of MR relates with hemodynamics deterioration. Methods: We enrolled 19 patients with IHD, who did not show significant MR in pre-operative period. All patients undertook OPCAB. During OPCAB, we positioned the beating heart in 4 positions for CABG, i.e., control, LAD-, RCA-, and LCX- positions, using Starfish heart positioner TM and Octopus 2 TM (Medtronic). In each position, we assessed the MR jet area by 2D-TEE and the hemodynamic parameters. We evaluated the relationship the worsening of MR and the hemodynamics deterioration. Results: Among the 4 positions, there was a significantly different in central venous pressure (CVP, Control: 9.6±2.7, LAD: 9.5±2.3, LCX: 10.9±2.4, RCA: 10.2±2.6 mmHg, P<0.01) and stroke volume (SV, Control: 69.1±23.3, LAD: 67.9±19.4, LCX: 52.3±14.4, RCA: 51.7±16.1 ml, P<0.01), but not in mean systemic pressure and mean pulmonary arterial pressure (mPA). The MR jet area was significantly increased in LCX and RCA positions compered to control position (control: 0.8±0.7 to LCX: 2.6±2.7, RCA: 2.0±2.2 cm 2 , each P<0.05). In LCX position, the MR jet area has the relationship with mPA (R=0.51, P<0.05) and SV (R=–0.71, P<0.01). On the other hand, the worsening of MR did not show the relationship with the wall motion score index, the location of asynergy and the hemodynamics before OPCAB. Conclusion: The dislocation of the beating heart during OPCAB (especially LCX and RCA positions) leads to the worsening of MR that relates with hemodynamics deterioration.