Time course of reverse remodelling of the left ventricle during support with a left ventricular assist device

Background: Support with a left ventricular assist device leads to normaliz ation of left ventricular chamber geometry, regression of myocyte hypertrop hy alterations in left ventricular collagen content, and normalized express ion of genes involved with excitation-contraction coupling in patients with heart failure. The objective of this study was to investigate the time cou rse of these processes, Methods: Passive left ventricular pressure-volume relationships were obtain ed from explanted hearts of 19 patients with heart failure undergoing trans plantation without left ventricular assist device support, 25 patients with heart failure supported before transplantation (duration Of support rangin g between S and 155 days), and 5 normal human hearts not suitable for trans plantation, left ventricular size was indexed by the volume at which left v entricular pressure reached 30 mm Mg, Left ventricular tissue samples were probed for sarcoplasmic endoreticular calcium adenosine triphosphatase 2a e xpression and processed for analysis of myocyte diameter and relative myoca rdial collagen content. Results: The volume at which left ventricular pressure reached 30 mm Hg was not significantly different between hearts without and with assist device support for less than 40 days, However, the volume at which left ventricula r pressure reached 30 mm Ha in patients with assist devices supported for m ore than 40 days was significantly smaller than that of the hoar ts without assist devices but was larger than that of normal hearts, A similar patter n was observed for myocyte diameter Sarcoplasmic endoreticular calcium aden osine triphosphatase 2a expression increased to normal levels by about 20 d ays of support with an assist device. Relative collagen content was signifi cantly increased in hearts supported for more than 40 days, Conclusion: Maximum structural reverse remodeling by left ventricular assis t devices is complete by about 40 days, Molecular reverse remodeling of sar coplasmic endoreticular calcium adenosine triphosphatase 2a expression is q uicker? being complete by about 20 days.