Stress Echo for Ischemic Mitral Valve Surgery

Chronic ischaemic mitral regurgitation (IMR) is a frequent complication of coronary artery disease (CAD), and is associated with a poor prognosis and outcome. The role of concomitant mitral valve surgery for IMR in patients undergoing coronary artery bypass grafting (CABG) remains controversial. After myocardial infarction IMR is associated with poor outcome and prognosis with double mortality rates, it reduces survival following surgical or percutaneous revascularization. However, there is no consensus on the cut-off value of IMR. The thresholds to define severe secondary mitral regurgitation are need to be evaluated with regards to their impact on prognosis after mitral valve intervention. The European guidelines is defined effective regurgitant orifice (ERO)-0.2 cm2 and regurgitant volume (RV)-30ml, as the threshold for severe IMR, because of severe prognosis of this group. Whereas American guidelines are defined it as ERO-0.4 cm2 and RV-60ml, as it was no evidence to impact intervention on the IMR with ERO-0.2 cm2 and RV-30ml. Partly it's explained by the dynamic nature of the secondary MR. About 30% of patients from the group with non-massive regurgitation at rest, have dramatically increasing it during exercise. However, some patient have not changes or decreasing IMR during exercise and, probably, they have not such a negative impact on the hemodynamic by IMR. The pervious comparative studies, that were the base for recommendations did not differ the patients with and without changes IMR during exercise. The current guidelines doesn't support the stress echo (SE) exams before operation for assessing necessity in mitral valve operation. It's due to lack of information that prove of influence for survival after surgery depending on IMR dynamic parameters.

IMR study hypothesis: Stress echocardiography data, including ERO, RV, pulmonary pressure (PA) pressure, beta-lines - B-lines, contractile reserve, could be indications for mitral valve intervention in patient with CAD and chronic secondary mitral regurgitation, undergoing CABG. The patients of the group with non-massive (ERO-0.2 cm2 and RV-30ml) IMR have positive effect by mitral surgery if they have increasing IMR during exercise test. The group with massive IMR (ERO≥0.4 cm2 and RV≥60 ml) will be better according clinic, echo, stress echo results in comparison with non-massive non-operated subgroup.

Aim: To assess the value of stress echo testing for ischemic mitral surgery indication in patients undergoing CABG.

Inclusion criteria for all projects are:

1. Age > 18 years
2. IMR, ERO≥0.2 cm2 and RV≥30 ml.
3. Indication for CABG