The implications for cardiac recovery of left ventricular assist device support on myocardial collagen content

BACKGROUND: To define the beneficial cellular changes that occur with chron ic ventricular unloading, we determined the effect of left ventricular assi st device (LVAD) placement on myocardial fibrosis. METHODS: We obtained paired myocardial samples (before and after LVAD impla ntation) from 10 patients (aged 43 to 64 years) with end-stage cardiomyopat hy. We first determined regional collagen expression of an explanted heart by a computerized semiquantitative analysis of positive picro-sirius red st ained areas. RESULTS: We found that there was no statistically significant difference in collagen content between regions of the failed heart studied. Next we dete rmined collagen content in these paired myocardial biopsies pre- and post-L VAD implantation. All 10 patients had significant reductions in collagen co ntent after LVAD placement with a mean reduction of 82% (percent of tissue area stained decreased from 32% +/- 4% to 4% +/- 0.8%, P < 0.001). CONCLUSION: In summary, these data demonstrate that chronic mechanical circ ulatory support significantly reduces fibrosis in the failing myocardium. ( C) 2001 by Excerpta Medica, Inc.