MITRAL REGURGITATION IN PATIENTS WITH CORONARY-ARTERY DISEASE AND LOWLEFT-VENTRICULAR EJECTION FRACTIONS - HOW SHOULD IT BE TREATED

In recent years, coronary artery bypass grafting has been extended to include patients with very low left ventricular ejection fractions. Sh ould concomitant mitral valve regurgitation be corrected simultaneousl y? Between January 1990 and July 1994, 43 patients with preoperative l eft ventricular ejection fractions less than or equal to 25% and echoc ardiographic evidence of concomitant mitral valve regurgitation (grade I, 18 patients; II, 19 patients; and III, 6 patients) underwent prima ry coronary artery bypass grafting. None of these patients underwent s imultaneous mitral valve surgery. Twenty-four patients (56%) had pulmo nary artery pressures greater than or equal to 40 mmHg (pulmonary hype rtension). The mean preoperative left ventricular ejection fraction wa s 18.7% +/- 4.4% (range, 10% to 25%), and the mean pulmonary artery pr essure was 45.6 +/- 15.8 mmHg. The average of number of grafts per pat ient was 4.5 +/- 1.5. Five patients underwent simultaneous repair of a left ventricular aneurysm. The hospital mortality rate was 4.7% (2/43 ). Transient low cardiac cutout occurred postoperatively in 13 patient s (30%). Sixteen patients (37%) had no postoperative complications. Th e average follow-up of the 41 hospital survivors was 6 months (range, 1 to 32 months). One patient died 8 months after surgery for an overal l mortality rate of 7%. Another 2 patients had graft occlusions that d id not require reoperation. In the 40 surviving patients, follow-up ec hocardiography revealed that 37 patients (93%) had either no mitral va lve regurgitation or only very mild mitral valve regurgitation (grade Il. Three patients had grade II mitral valve regurgitation, but none r equired mitral valve surgery. The New York Heart Association functiona l class improved significantly in all hospital survivors (from 3.4 +/- 0.6 to 1.7 +/- 0.7; p > 0.001), and left ventricular ejection fractio ns rose from 19.0% +/- 4.6% to 42.0% +/- 8.3%. Coronary artery bypass grafting is possible in patients with very low left ventricular ejecti on fractions who present with 2- or 3-vessel disease, significant coro nary artery stenoses (greater than or equal to 70%), and angina. The m ortality rate is acceptable and morbidity is low If there is no ruptur e of papillary muscle or chordae, concomitant ischemic mitral regurgit ation (grades I through III) seems to return to normal after coronary artery bypass grafting and, therefore, does not need to be corrected s urgically during the primary operation.