Novacor left ventricular assist system versus heartmate vented electric left ventricular assist system as a long-term mechanical circulatory support device in bridging patients: A prospective study

AbstractObjective: Long-term mechanical circulatory support as a bridge-to-transplantation procedure and bridge to recovery is of increasing importance. The implantable left ventricular assist devices, Novacor N100 left ventricular assist system (Baxter Healthcare Corporation, Berkeley, Calif) and TCI HeartMate vented electric left ventricular assist system (Thermo Cardiosystems Inc, Woburn, Mass), have proved to be efficient devices in bridge-to-transplantation settings and for prolonged support. The two systems were compared with regard to reliability and morbidity. Methods: Between October 1996 and March 1998, a prospective, single-center study was done that included 40 patients, 20 of whom were treated with the Novacor system and 20 of whom were treated with the HeartMate device. The diseases were mainly dilated cardiomyopathy (13/9) and ischemic cardiomyopathy (6/10). There were no statistically significant differences between the two groups regarding age, sex, preoperative clinical blood chemistry values, hemodynamic data, or risk factors. Results: There were no statistically significant differences between the two groups with regard to postoperative hemodynamics, organ recovery, out-of-hospital support, and survival to heart transplantation. Mean duration of support was 235.3 ± 210 days for the Novacor group and 174.6 ± 175 days for the HeartMate group and mean out-of-hospital support was 241 ± 179 days and 166 ± 152 days for the two groups, respectively. Neurologic complications occurred significantly more often among the Novacor group, whereas the HeartMate group had a higher prevalence of infections and technical problems, which was statistically significant. Survival to transplantation was 65% for the Novacor group and 60% for the HeartMate group. Conclusions: Most patients had organ recovery with left ventricular assist system support, and a considerable number of patients in both groups underwent transplantation. However, both devices need revision to address the current problems, that is, thromboembolism for the Novacor device and infection and reliability for the HeartMate device. (J Thorac Cardiovasc Surg 2000;119:581-7

The structural examination of myocardial samples from patients with end-stage heart failure supported by ventricular assist devices using electron-microscopy and amino acid analysis reveals low degree of reverse remodeling

Milting H, Jacob M, Kassner A, et al. The structural examination of myocardial samples from patients with end-stage heart failure supported by ventricular assist devices using electron-microscopy and amino acid analysis reveals low degree of reverse remodeling. JOURNAL OF HEART AND LUNG TRANSPLANTATION. 2004;23(4):396-404.Background: Chronic heart failure is a multifactorial, progressive disease of many causes and is associated with complex ventricular remodeling. Deposition of extracellular matrix proteins and sarcomeric disarray of the myocytes occur in end-stage heart failure. Ventricular assist devices (VAD), implanted as bridge to transplantation, may reverse ventricular remodeling. Although successfully weaning patients from VAD support has been reported, it is not clear to what degree reversal of remodeling,occurs in unloaded failing hearts. Because collagen deposition, and ultrastructural disarray are hallmarks of myocardial remodeling, we analyzed the myocardial ultrastructure and collagen content of VAD-supported hearts before and after mechanical unloading. Methods: We used amino acid analysis to measure collagen content (4-hydroxyproline content) in 24 transplant candidates receiving VAD support. We used transmission electron microscopy to examine the ultrastructure in 6 patients receiving VAD support. Results: The 4-hydroxyprohne content increased significantly at VAD implantation and was not altered by mechanical unloading. The ultrastructure showed signs of persisting. cardiomyopathy. Conclusion: Mechanical unloading does not alter the total collagen content of the supported, failing heart. Thus, structural reversal of the remodeling process associated with heart failure is not a general phenomenon in mechanically unloaded hearts