Search

Introduction: Magnitude of functional recovery of the left ventricle (LV) is one of the critical determinants of prognosis post-implantation of ventricular assist device (iVAD) for non-ischemic dilated cardiomyopathy (NIDCM). Although predictive factors of the functional recovery are not fully understood, presence of immunocompetent cells in the myocardium is reported to be associated with the pathological stage and/or the myocardial viability. Hypothesis: There are some relationships between functional recovery post-iVAD implantation and distribution of the immunocompetent cells in NIDCM. Methods: In the last 5 years, iVAD such as HeartMateII was implanted in 50 cases with NIDCM for bridge-to-transplantation purpose, followed by β blocker and/or ACE inhibitor in the aim to enhance functional recovery. Of them, 46 cases, who were examined by echocardiography at 6 months post-iVAD implantation, were enrolled in this study. Results: Six cases (13%) showed improvement of EF by 5-10% at 6 months postoperatively, while 4 cases (9%) showed improvement of EF by 10% or more in the same interval. Reduction of LV dimension was more prominent in the cases showing greater recovery of EF. Serum level of brain natriuretic peptide was predominantly reduced in the cases showing EF improvement by 10% or more (-1044 pg/ml), as compared to the cases showing EF improvement by 5-10% (-627 pg/ml) or the other cases that failed to show EF improvement more than 5% (-528 pg/ml). In the pathological analysis of LV apex at the time of iVAD implantation, immunocompetent cells, such as CD3-positive T cells or CD68-positive macrophages, were predominantly present in the cases showing EF improvement by 10% or more, as compared to the other cases (Figure). Conclusions: Despite aggressive medical treatments post-iVAD implantation, functional recovery was not frequently seen in advanced stage of NIDCM. Immunocompetent cells in the LV myocardium might be a key to predict myocardial viability of this pathology. [ABSTRACT FROM AUTHOR]