Ischemic mitral valve regurgitation and symptomatic coronary artery disease: a surgical strategy

ABSTRACT

In recent years coronary artery bypass grafting [CABG] has been extended to include patients with very low left ventricular ejection fractions [LVFF], also frequently with coexisting mild to moderate mitral valve regurgitation [MR]. The question is, should MR be corrected simultaneously with a myocardial revascularization or not? Between January 1990 and December 1996, 82 patients with preoperative LVEF papillary muscle rupture [Grade I- 28%, II-35% and III- 37%] underwent primary CABG. None of them underwent simultaneous mitral valve surgery. The mean preoperative LVEF was 0.17 +/- 0.04 [0.10-0.25], mean PAP 43.8 +/- 15.9 mmHg. An average of 4.4 +/- 1.5 grafts/patient were placed. The overall mortality was 3.7%, [3/82]. Transient post-operative low cardiac output syndrome occurred in 24 patients [29%]. Thirty-two patients [39%] had no postoperative complications at all. Seventy-nine hospital survivors were followed up over a period of 18 months [6-48 months] on average. There was one death [8 months post-operatively] and 2 graft occlusions, not requiring redo surgery. At the end of the follow up echocardiography showed that 45 patients had no MR at all and 28 patients had MR - Grade 1, a total of 73 patients [94%]. Five patients had Grade Il-Ill MR, none of them requiring mitral valve surgery. All patients improved their NYHA functional class, from 3.5 +/- 0.7 to 1.8 +/- 0.5 and the LVEF from 0.17 +/- 0.04 to 0.46 +/- 0.08, p<0.001. Coronary artery bypass grafting is a possible treatment for patients with very low LVEF, provided the patient has a 2- or 3-vessel disease with significant coronary artery stenoses, >/= 70%, and angina. Mortality and morbidity are low. Moderate to severe coexisting MR [Grade Il-Ill] seems to normalize after the myocardial revascularization and should therefore not be surgically corrected at the primary operation, if there are no echocardiographic evidence of chordal or papillary muscle rupture. Peroperative control echocardiography is recommended