<p><strong>Aim.</strong> The issues of safety of off-pump myocardial revascularization in patients with severe ischemic mitral regurgitation remain insufficiently studied. Control of transport and oxygen consumption allows one to assess some of the safety aspects of this technique. The study was designed to evaluate the safety of myocardial revascularization without cardiopulmonary bypass in a combined operation for patients with ischemic mitral regurgitation and a similar operation under cardiopulmonary bypass and cardioplegia by assessment of the main parameters of transport and oxygen consumption.<br /><strong>Methods.</strong> Forty-two adult patients scheduled for elective coronary artery bypass grafting in combination with mitral annuloplasty were randomized into two groups: off-pump (22 patients) and on-pump (20 patients). In the off-pump group, coronary artery bypass grafting was performed on a beating heart without cardiopulmonary bypass, whereas in the on-pump group it was conventional coronary artery bypass grafting on a cardiopulmonary bypass with cardiac arrest. The coronary artery bypass grafting stage was performed before intervention on the mitral valve.<br /><strong>Results.</strong> On completion of the coronary artery bypass grafting stage, the cardiac index, the oxygen delivery index and the blood lactate level in the off-pump group were lower than those in the on-pump group by 20%, 17% and 100% (p = 0.01, 0.02, 0.003), respectively, while the consumption index and oxygen extraction were higher by 17% and 94% (p = 0.016 and 0.0001), respectively. In the off-pump group, the oxygen consumption index remained stable at all stages of the operation and the C-reactive protein level tended to decrease between 10–14 days after surgery (p = 0.13).<br /><strong>Conclusion.</strong> Implementation of off-pump coronary surgery in a combined operation for patients with ischemic mitral regurgitation does not lead to disruption of transport and oxygen consumption, does not exacerbate the systemic inflammatory response and can be considered a safe method for this category of patients.</p><p>Received 5 April 2017. Revised 21 July 2017. Accepted 24 July 2017.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and study design: A.S. Zavolozhin, A.N. Shonbin<br />Data collection and analysis: A.S. Zavolozhin, D.O. Bystrov, M.V. Elizarov, G.A. Ivanov <br />Drafting the article: A.S. Zavolozhin<br />Critical revision of the article: A.N. Shonbin, D.O. Bystrov<br />Final approval of the version to be published: A.N. Shonbin</p><p><strong>Acknowledgement:</strong> The authors express their gratitude to the staff of cardiac surgeons of City Hospital No. 1 (Arkhangelsk) for collaboration and support in doing this research.</p>
I-1-11 Assessment of coronary sinus blood flow and myocardial oxygen consumption following coronary artery bypass grafting
