Intracoronary shunts reduce transient intraoperative myocardial dysfunction during off-pump coronary operations

Abstract

Background. This study investigated the hemodynamic changes in patients undergoing multiple vessel beating heart coronary revascularization in the presence or absence of an intracoronary shunt. Methods. Forty patients were randomized to off-pump with a shunt (n = 20) or with the proximal coronary artery occluded by a soft snare (n = 20). Hemodynamic measurements were recorded at base line, during construction, and after completion of each distal anastomosis. Results. Grafting of the left anterior descending coronary artery anastomosis was associated with a significant decrease in stroke volume, cardiac index, and mean arterial pressure, and an increase in pulmonary capillary wedge pressure and systemic vascular resistance in the snare but not in the shunt group. During grafting of the posterior descending coronary artery there was a marked decrease in stroke volume and cardiac index, and an increase in central venous pressure in both groups, and an increase in heart rate, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, and systemic vascular resistance only in the snare group. The most extensive changes were observed during the circumflex coronary artery anastomosis with a reduction in stroke volume, cardiac index, and mean arterial pressure, and an increase in central venous pressure, pulmonary capillary wedge pressure, pulmonary arterial pressure, and systemic vascular resistance in both groups. In all settings, these changes were transient and recovered after the heart was returned to its anatomical position in the shunt group, whereas stroke volume and cardiac index remained reduced, and systemic vascular resistance was elevated in all settings in the snare group. Conclusions. Stabilization of the left anterior descending coronary artery to perform the anastomosis resulted in temporary hemodynamic changes, which are prevented by the use of an intracoronary shunt. The hemodynamic deterioration during the construction of the posterior descending coronary artery and circumflex coronary artery anastomoses is transient in the shunt group, whereas the snaring technique is associated with an impairment of early functional recovery.