Partial left ventriculectomy: Which patients can be expected to benefit?

Background. Although some patients with end-stage heart disease will benefi t from a partial left ventriculectomy, no criteria have been found for iden tifying this group preoperatively. Our experience with partial left ventric rulectomy at two institutions-the Texas Heart Institute in Houston, TX, USA , and Dedinje Cardiovascular Institute in Belgrade, Yugoslavia-showed a hig her survival rate and better postoperative myocardial function in the Yugos lavian patients. Methods. We reviewed data from 42 patients (21 at each center) who had idio pathic cardiomyopathy, a left ventricular end-diastole dimension of more th an 70 mm, wall thickness of 1 cm or greater, and New York Heart Association class III or IV symptoms. The only significant difference in preoperative status between the two groups was duration of symptoms. Histologic specimen s, blinded as to origin, were graded with regard to myocyte hypertrophy, cy toplasmic vacuolation, and fibrosis. Computer-assisted myocyte and nuclear morphometry was also performed. Results. Immediately postoperatively, there were no significant intergroup differences in the reduction in cardiac dimension or in corrections of mitr al regurgitation. During 6-month follow-up, however, the Texas Heart Instit ute patients had a lower cardiac index (1.8 versus 3.0 L.min(-1).m(-2); p = 0.001) and left ventricular ejection fraction (24% versus 34%; p = 0.006) than the Dedinje Cardiovascular Institute patients. The Texas Heart Institu te patients differed from the Dedinje Cardiovascular Institute patients in the degree of severe or moderate changes in myocyte hypertrophy (90% versus 29%; p = 0.0003) and fibrosis (71% versus 29%; p = 0.006), as well as in t he measurements of median myocyte diameter (35 +/- 7 pm versus 27 +/- 4 mu m; p = 0.0002) and median nuclear size (15 +/- 4 mu m versus 12 +/- 2 mu m; p = 0.0029). Conclusions. In the Texas Heart Institute patients, the significant intergr oup difference in clinical outcome may have been related to increased myocy te hypertrophy and fibrosis. Further studies should be performed to determi ne the usefulness of these criteria in selecting patients for partial left ventriculectomy. (C) 2000 by The Society of Thoracic Surgeons.